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EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 Natural Hazards Natural Hazards www.nat-hazards-earth-syst-sci.net/13/625/2013/ doi:10.5194/nhess-13-625-2013 and Earth System and Earth System © Author(s) 2013. CC Attribution 3.0 License. Sciences Sciences Discussions Open Access Open Access Atmospheric Atmospheric Chemistry Chemistry and and Physics Extreme events in : 14 680 BP–2012 Discussions Open Access Open Access Atmospheric Atmospheric L. O’Brien1, J. M. Dudley2, and F. Dias1,3 Measurement Measurement 1School of Mathematical Sciences, University College Dublin, Dublin, Ireland 2Institut FEMTO-ST, UMR 6174 CNRS-Universite´ de Franche-Comte,´ Besanc¸on, France Techniques Techniques 3Centre de Mathematiques´ et de Leurs Applications (CMLA), Ecole Normale Superieure´ de Cachan, Cachan, France Discussions Open Access Open Access Correspondence to: F. Dias ([email protected]) Biogeosciences Biogeosciences Received: 9 July 2012 – Published in Nat. Hazards Earth Syst. Sci. Discuss.: – Discussions Revised: 15 January 2013 – Accepted: 31 January 2013 – Published: 11 March 2013 Open Access Open Access Abstract. The island of Ireland is battered by from all ern Ireland. From an oceanographic perspective, however, it Climate sides, most ferociously on the west coast as the first port of is necessary to consider the full designatedClimate call for waves travelling across the Atlantic . However, of Ireland, which is of courseof very the much Past bigger and which of the Past when discussing ocean events relevant to the nation of Ire- indeed is one of the largest territories in Europe, as Discussions land, one must actually consider its significantly larger desig- shown in Fig. 1. Open Access nated continental shelf, which is one of the largest seabed ter- But even when it is possible to delimit a geographical area, Open Access ritories in Europe. With this expanded definition, it is not sur- a problem that arises immediately when attempting to pre- Earth System prising that Ireland has been subject to many oceanic events pare a catalogue of eventsEarth is that of System the particular time frame which could be designated as “extreme”; in this paper we of interest, and the differing fidelityDynamics of the observations. In Dynamics present what we believe to be the first catalogue of such the interest of completeness, we have tried to include as many Discussions events, dating as far back as the turn of the last ice age. events as we have been able to document, albeit that some- times we summarise observations from the distant past and Open Access Open Access from testimonials where theGeoscientific reliability of the observations Geoscientific cannot be verified. ButInstrumentation when viewed as a whole, it is clear Instrumentation 1 Introduction that there is a great deal ofMethods evidence supporting and a long his- Methods and tory of large ocean wavesData and currents Systems on the sur- The study of extreme wave events on the ocean is a rounding Ireland as well as on its coast. This said, of course Data Systems rapidly expanding area of research worldwide that links to- such a study cannot be exhaustive, but we have attempted Discussions Open Access gether sailors, marine officers, oceanographers, physicists Open Access to be as complete as possible at the time of preparation. In Geoscientific and mathematicians around a common aim of understand- fact, our desire to be comprehensiveGeoscientific has encouraged us to in- ing the formation and dynamics of large ocean waves and clude in this overview a short section including results from Model Development currents. Although much work in this area is based on mod- Model Development legend, and whilst the scientific basis of such events is less Discussions elling and experiments in controlled wave tanks, the starting certain than the other results we present, we believe that such point of all studies in this field is of course observation in Open Access results are complementary to the more reliableOpen Access observations the natural world. To this end, several reviews of observa- described in the rest of thisHydrology paper. and Hydrology and tional ocean events which could be classed as extreme have This paper is organised as follows. In Sect. 2, we first clar- appeared in the literature (Kharif and Pelinovsky, 2003; Tinti ify our use of terminologyEarth to describe System different categories of Earth System et al., 2004; Ambraseys and Synolakis, 2010; Nikolkina and “wave” events as storm waves,Sciences and rogue waves. Sciences Didenkulova, 2011), but there is clearly the need for as much In Sect. 3, we present the main catalogue of documented detailed cataloguing as possible. The purpose of this paper is Discussions Open Access wave events in Ireland listed under these threeOpen Access categories, to present such an overview for the nation of Ireland. whilst Sect. 4 presents additional related descriptions, includ- Ireland of course refers to the well-known island situated ing those from legend. Section 5 presents a discussion of how Ocean Science on the western edge of Europe, which we consider here in Ocean Science these wave events may relate to boulder deposits in Ireland, Discussions its entirety including both the and North- Open Access Published by Copernicus Publications on behalf of the European Geosciences Union. Open Access Solid Earth Solid Earth Discussions Open Access Open Access

The Cryosphere The Cryosphere Discussions Manuscript prepared for Nat. Hazards Earth Syst. Sci. with version 4.2 of the LATEX class copernicus.cls. Date: 15 January 2013

Extreme wave events in Ireland: 14,680 BP - 2012

Laura O’Brien1, John M. Dudley2, and Fred´ eric´ Dias1,3 1School of Mathematical Sciences, University College Dublin, Dublin, Ireland 2Institut FEMTO-ST, UMR 6174 CNRS-Universite´ de Franche-Comte,´ Besanc¸on, France 3Centre de Mathematiques´ et de Leurs Applications (CMLA), Ecole Normale Superieure´ de Cachan, Cachan, France

Abstract. The island of Ireland is battered by waves from all necessary to consider the full designated continental Shelf sides, most ferociously on the west coast as the first port of of Ireland which is of course very much bigger and which call for waves travelling across the Atlantic Ocean. However, 35 indeed is one of the largest seabed territories in Europe, as when discussing ocean events relevant to the nation of Ire- shown in Fig. 1. 5 land, one626 must actually consider its significantly larger des- L. O’Brien et al.: Extreme wave events in Ireland ignated continental shelf which is one of the largest seabed territorieswhich in Europe. are of particular With this relevance expanded to cliff-top definition, deposits it on is the The$Porcupine$Basin$ The$Barra$Fan$ not surprisingwest coast.that Ireland Finally has in Sect. been 6 subject we present to many an overall oceanic conclu- events whichsion could and make be designated suggestions asfor “extreme”; further directions in this of paper research. 10 we present what we believe to be the first catalogue of such events, dating2 Categories as far back of as ocean the wavesturn of the last ice age.

We consider “extreme wave” events in Ireland in three broad categories that we discuss in more detail below: storm waves, 1 Introductiontsunamis, and rogue waves. In the context of quoting from various sources as we do in the following section, it must be The studyrecognized of extreme that the wave descriptions events used on by the the public ocean and is media a 15 rapidly-expandingdo not always area follow of research precise scientific worldwide definitions, that links but to- we at- gether sailors,tempt to marine – wherever officers, possible oceanographers, – refer back to the physicists definitions in and mathematiciansthis section when around commenting a common on the aim results of understand- in the catalogue below. ing the formation and dynamics of large ocean waves and Storms are very common in Ireland (driven by the strong 0"""""60""""120"""180"""240"""300"km" currents. Althoughwinds on the much west work coast in in this particular), area is but based tsunamis on mod- are not 20 eling andcommon experiments due to in the controlled location of wave Ireland tanks, relative the to starting the tectonic Fig. 1. A snapshot from The Real Map of Ireland from the Irish point of allplate studies boundaries. in this In field fact, is the of number course of observation docu-in Fig.Marine 1. A Institute, snapshotwww.marine.ie from The Real, with Map the locations of Ireland of the from Barra The Fan Irish the naturalmented world. in Ireland To this since end, 1760 several is just reviews over 100, of and observa- the largest Marineand the Institute, Porcupinewww.marine.ie Basin overlaid., with The red the line locations indicates of the the current Barra Fan tional oceanof these events has which a magnitude could of be only classed 4.4. However, as extreme earthquakes have anddesignated the Porcupine Irish continental Basin overlaid. shelf, which The red is one line of indicatesthe largest the seabed current appeared inand the literature very (Kharif far from and Ireland Pelinovsky, itself can 2003; still Tinti generate designatedterritories Irish in Europe. continental shelf which is one of the largest seabed tsunamis that travel great distances without losing much en- 25 et al., 2004; Ambraseys and Synolakis, 2010; Nikolkina and territories in Europe. Didenkulova,ergy, 2011), and events but like there this is have clearly affected the need Ireland for in as the much past. There are two historical submarine mass movement events 2.1 Storm waves detailed cataloguing as possible. The purpose of this paper is of particular interest: the first occurred in the Barra Fan, off- But even when it is possible to delimit a geographical area, to presentshore such north-west an overview of Ireland for the (Owen nation et of al. Ireland., 2010), and the sec- Storm waves are surface waves that reach unusually Irelandond of course in the Porcupine refers to theBasin, well-known offshore south-west island situated of Ireland a problemlarge amplitude that arises due to immediately forcing by strong when . attempting For exam- to pre- pare a catalogue of events is that of the particular timeframe 30 on the western(Huvenne edge et of al. Europe,, 2002). Both which of wethese consider locations here are indicatedin its ple, gale to hurricane force winds ranging from 8 to 12 on entirety includingin Fig. 1. Furthermore,both the Republic a phenomenon of Ireland referred and Northern to as “meteo-40 ofthe interest, Beaufort and scale the can differing produce fidelity maximum of wavethe observations. heights from In ≥ Ireland. Fromtsunami” an (a oceanographic meteo- perspective,is an atmospherically however, induced it is de- the7 interest.5 m to of16 completeness, m (Metoffice.gov.uk we have, 2012 tried). to include as many structive ocean wave in the tsunami frequency band) could eventsThe as climate we have in Ireland been able is dominated to document, by the Atlantic albeit that Ocean, some- Correspondencealso pose to: a threatFred´ eric´ to Ireland, Dias and since this has been docu- timesand weits associated summarise wind observations patterns are fromresponsible the distant for the past gen- and ([email protected])mented in England (Haslett et al., 2009), it is reasonable to fromeration testimonials of a large population where the of reliability storm waves. of The the polar observations front assume that meteo-tsunamis may also have impacted Irish (transition between warm dense air moving north and cold shores in the past and pose a threat for the future. Rogue dry air moving south) is a feature that plays an important waves or freak waves refer to a particular class of wave role in Irish weather, and winds generally blow from the events that has only recently been accepted as a distinct wave south and west. The Atlantic low-pressure systems move class (Nikolkina and Didenkulova, 2011). However, as we eastwards across Ireland in December and January bringing describe here, it is possible that many fatalities in Ireland strong winds. Occasionally, in late summer and early autumn may well have arisen from events that could be considered tropical depressions mixing with North Atlantic depressions as rogue waves. can produce severe storms such as the one that occurred dur- The vast majority of waves on the ocean are surface grav- ing the in August 1979. From 1961 to 1990 the ity waves generated by the wind blowing over a large stretch mean number of days per year with gales at , of water surface. After the (wind ) phase of generation Co. , was 66 (met.ie, 2012). This highlights just how by local winds, the propagation of surface waves away from prevalent strong winds are in Ireland, and motivates our con- the generation area yields ocean . In general, surface sideration of storm waves as an important category of ex- waves at any particular point on the ocean are a combination treme ocean events in this catalogue. of locally generated waves from a local wind sea and swell Even though storm surges are obviously associated with generated remotely (mixed sea states). Extreme sea levels oc- storms, we prefer to include them in the next section on cur when particular wave generation or propagation dynam- tsunamis, the reason being that storm surges can be con- ics yield surface elevations that are larger than expected for sidered as long-period waves with a typical of the particular area considered. several tens of kilometers like tsunamis.

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ L. O’Brien et al.: Extreme wave events in Ireland 627

2.2 Tsunamis acteristics. Meteo-tsunamis are very sensitive to generated by local coastal geometry and topography which Tsunami waves are one of the most catastrophic events that can cause large , for example inlets, bays, and har- can naturally occur. They have devastated countries at severe bours (Haslett and Bryant, 2009). Multiple events have been human cost, wiping out miles of coastline, towns and villages analysed along the coast of southern Britain, in particular by on a path of destruction. The recent events in Japan in 2011 Haslett and Bryant (2009). Also, Dawson et al. (2000) have and Indonesia in 2004 are a stark reminder of their destruc- documented abnormal sea-surface fluctuations in South West tive power (Synolakis and Bernard, 2006). England. Tsunamis are generated from a sudden impact on the On 27 June 2011, a 0.5–0.8 m high tsunami struck approx- ocean caused by earthquakes, landslides or volcanoes dis- imately 200 miles of coastline on the south-west of England. placing large volumes of water. We note that although the Eyewitness reports said that the weather was extremely warm geological origin of tsunamis is that most often cited, the and humid at the time and the sea was “as calm as a mill effects of landslides and volcanoes can be as equally de- pond.” Then the sea retreated and suddenly rushed back in. structive (Okal and Synolakis, 2003). In the open ocean a Also there was a feeling of static in the air and people’s “hair tsunami is usually only a few tens of centimeters high, trav- was standing on end” (The Guardian, 29 June 11). Based on els at around 800 km h−1, the speed of a commercial jet air- the range of impact and lack of height variation, the British plane, with a wavelength of the order of 100 km. The basic Geological Survey (BGS) indicated that it was likely to have physics of tsunamis on the open ocean follows that of a linear been a meteo-tsunami caused by a squall, or several squalls, shallow water wave. that developed during a summer storm. If meteo-tsunamis Tsunamis conserve energy well until reaching the shore can explain some large wave events in England, then maybe where they are compressed because of shoreline similar events in Ireland can be linked to meteo-tsunamis. and they drastically grow in height as they slow down. It is Mecking et al. (2009) carried out numerical simulations of common that the first sign of a tsunami is an extreme with- Tropical Storm Helene (2000) driven by atmospheric pres- drawal of the sea followed by a wave that seems small in the sure and surface winds. They were able to capture the ob- distance, but which grows rapidly and which can be followed served response of unexpected “rapid ” along the coast by successive waves sometime after. The first wave is not al- of Newfoundland during this storm. This rapid rise in ways the largest (Stefanakis et al., 2011). Without the proper can be compared to a tsunami and so could be categorized infrastructure and education on the warning signs and evac- as a meteo-tsunami. This study highlights the importance of uation methods, tsunamis can have deadly effects on coastal capturing the atmospheric pressure effects when modelling communities. the response to a storm and may be a first step to- wards modelling meteo-tsunamis. 2.2.1 Storm surges and meteo-tsunamis 2.3 Rogue waves A is an increase in the level of sea surface asso- ciated with low atmospheric pressure, and as such is a long- Rogue or freak waves are large, unpredictable and highly period wave. Storm surges can have particularly destructive powerful waves that have the potential to cause huge damage effects in coastal areas where there is a significant difference (Kharif and Pelinovsky, 2003). They seem to appear from between low tide and high tide. A meteo-tsunami is also a nowhere with a height 2–3 times that of the surrounding sea long-period wave that possesses tsunami like properties but state, exist for a short time and then disappear. is meteorological in origin. The meteo-tsunami phenomenon There is no universal definition of a , but one has much in common with storm surges (Levin and Nosov, often used is that of a wave which is at least twice as high 2009). The period of storm surges can range from several (trough to crest) as the significant (four times minutes up to several days. It is important to emphasize that the standard deviation of the surface elevation) of the sur- even though storm surges and locally generated wind waves rounding waves. Until recently, stories of rogue waves were can be present together, we consider them separately, since thought to be folklore or exaggerated because they could wind waves and choppy are characterised by periods not be explained scientifically, but there is now acceptance smaller than a minute. The only formal difference between that they constitute an important class of wave, although a storm surge and a meteo-tsunami consists in the difference there is unlikely to be only one unique generation mecha- between their maximum periods. The maximum period for nism. Rogue waves occur in both deep and shallow waters, a tsunami does not exceed several hours, while storm surges and may act as a single wave or a group of waves. It is al- may last several days. most certainly the case that different mechanisms may con- In recent years more attention has been paid to tsunamis tribute to the formation of rogue waves, including both lin- of meteorological origin (Rabinovich et al., 2009). Extreme ear and nonlinear processes influencing waves both in the wave formation in coastal waters may be considered as a local vicinity of a wind sea, as well as propagating swell. meteo-tsunami if it takes on long-period tsunami like char- For example, linear superposition and directional focussing www.nat-hazards-earth-syst-sci.net/13/625/2013/ Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 628 L. O’Brien et al.: Extreme wave events in Ireland

Mullet##Pen.#(S1)# T1,#T2#(off#map)#

Eagle#Island# T12# R13#(M4)# R4#R6# R8# R7# Mullaghmore# Aran#Islands##S1# S7,#S10,#R1# R9# Blacksod#Pt.## T9# M6# R5#S6# Clew#Bay#(T9)# (off#map)# Dublin#T4,#T10# M1# T7# S5# M2# Cliffs#of#Moher# T11# Westport# R10# Quay# T3b,#T10# S9,#R3# S14# S11,#T10# R12# S8# Bandon# S4,#R11# R2# S2# T8# # T3a# M5# S12,#T5,#T6# T7## M3# (off#map)# Ilfracombe#T10# Fastnet## Southampton#T10# ##S15# #(T3a)#

New#Ross# Fastnet#Race#S13#

Waterford# Jersey#T10# Dungarvan#

Waterford#&## The$Extreme$Waves$Map$of$Ireland$ #(T3b)#

Fig. 2. Location of extreme wave events in Ireland (see Table 1). effects could readily increase local wave height in the pres- deep water waves and light propagation has indeed been able ence of local wind, whilst nonlinear instabilities could in- to confirm many predictions (Peregrine, 1983) of nonlinear crease local wave group amplitude for a propagating swell. deep water wave growth and decay in an optical environment To our knowledge, the first plausible explanation of how an (Kibler et al., 2010, 2012). This work has since motivated di- extraordinary (abnormal) wave condition can be realized in rect observation of nonlinear waves in water tanks, and thus it the ocean was provided through analyses of the Suwa-Maru seems likely that a more complete picture of the role of non- incident on 23 June 2008 (Tamura et al., 2009). Crossing linearity in water wave growth and shaping will soon emerge sea conditions were a precursor to the development of a nar- (Chabchoub et al., 2011, 2012). row spectrum. When the resulting unimodal wave spectrum is sufficiently narrow and nonlinear, a freak wave might oc- cur due to . 3 Events It is important to state that rogue waves are intrinsically random in nature, and thus deterministic ocean processes We use the Before Present (BP) timescale, as is common in such as tsunami and storm surge should probably not be in- archaeology and geology, to specify when events in the past cluded in the category of rogue waves. In the context of non- occurred, and we adopt the standard practice to use 1 Jan- linear wave theories which are currently being considered in uary 1950 as the origin of the age scale. great detail, it is interesting to remark that many of the theo- In this section extreme wave events in Ireland are cat- retical ideas underlying nonlinear water wave formation have alogued in terms of the three categories described above: not actually been confirmed in the hydrodynamic environ- storm waves, tsunamis, and rogue waves. This categoriza- ment. However, recent work using analogies between ocean tion is made based on an overall assessment of the available

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ O’BrienL. O’Brienet al. et: al.:Extreme Extreme wave wave events events in Ireland in Ireland 629 7

outIn of 1837 bed into there water.” is an She account tells how of a a huge terrible wave: gale “An was oceanblow- ingwave all (there night being and how no hurricane the “Green at the Seas time). were . . going swept over over our the houses.”island, the The lightkeepers door to their with room their was families broken taking down, refuge and all in 345 thethe rooms tower, “filled just in with time the to sea”. save The their sea lives, was when raging the outside, roofs theof the “window dwelling frames, homes roofs were and carried all theaway” house (The was Irish going Times to, pieces”15 October and 1869). the “slates were being lifted off like flies”. At a neighbouringOn 11 March house 1861 the another sea “ran huge over wave the did house considerable smashing thedamage. door in The the Commissioners hall, filling to rooms” of Irish and Lights was coming (CIL, 2012 in the) 350 chimneydescribe putting the event: the fire“On out. the The 11 houseMarch “got 1861 all at broken midday down, the up-stairslight room got of knocked the East into tower one. was The struck windows by the all sea broken smash- in, theing staircase 23 panes, carried washing away.” some As of for the the lamps lighthouse down the tower stairs, the “lightsand damaging were put the out reflectors several withtimes, broken all the glass panes beyond in the repair. tower windowsIt must have were been put an in.” incredible The store wave houses to have “were come levelled up 133 to 355 thefeet ground, [40.5 m] pantries of rock and and everything then a further smashed”. 87 feet She [26. also5 m] de- of scribeslighthouse paving tower stones to cause (flags) so muchbeing damage.” transported: “Flags were tornOn up 29 and December tossed around 1894 a like storm marbles”. “damaged She the finishes dwellings by Fig.Fig. 3. 3. EagleEagle Island Island, (picture picture from Nationalfrom National Geographic, Geographictravel. sayingof the East “the stationLower station beyond is repair a complete and also wreck.” broke On the the lantern 25th nationalgeographic.com/travel/countries/ireland-photos/). travel.nationalgeographic.com/travel/countries/ireland-photos/ Januaryglass, put 1935 out another the light storm and struck damaged the light the protecting putting it out wall” of 360 action(CIL, 2012 (CIL).). In January a letter writtenof 1987 by and one February of the of inhabitants 1988, “sub- of stantialEagle Island, damage Polly was Ryan again describes done by tostorms” her sister (CIL). Kate the hor- descriptions, although of course there is uncertainty when the rorLighthouse of what happened photographer that night John (Ryan Eagle, 1895 (Eagle)). She describes and the 310 3.1wave Storm descriptions Waves are based on eyewitness accounts. There someothers of in the her damage house were that wokenhas been “at done half atpast Eagle two Island: to jump “On out could well be some overlap between our categorizations, and oneof bed occasion into water.” a rock wasShe throwntells how up a the terrible high cliffs gale by was a severe blow- 3.1.1 1837, 1861, 1894, 1935, 1987, 1988, 1989: The in cases where there may be more than one possibility, it is 365 storm,ing all it night smashed and how the glass the “Green and then Seas the were tower going filled over up with our noted. However,, our aim is Co. to provide Mayo [S1] an important first step waterhouses.” [...]. The The door door to had their to be room drilled was to broken let the water down, before and all it in developing as complete a catalogue as possible for extreme couldthe rooms be opened.” “filled with Given the the sea.” description, The seathis was was raging most outside, likely Thewave Eagle events Island in Ireland. and Blacksod Point on the Mul- duringthe “window the 1861 frames, or 1894 roofs event. and all the house was going to letTwo peninsula of the in Co.events Mayo we (see describe first inset – the of Peach Fig. 2 Slide for map in pieces”Although and thewe “slateshave included were being these lifted events off here like flies.”as storm At 315 location and Fig. 3 for a picture of Eagle Island) have been 14 680 BP and the Storegga Slide in 8200 BP – occurred 370 waves,a neighbouring a wave height house theof 67 sea m “ran is extraordinary. over the house It smashing is likely hitaround by extreme the end waves of the on multiple last glacial occasions. period. Eagle These Island are both lies thatthe door such in a wave the hall, height filling represents to rooms” the and water was height coming after in pro- the justlarge-scale off the Mulletsubmarine peninsula landslides, close and to the it is continental speculated shelf. that jectionchimney at putting the base the of fire the out. lighthouse. The house But “got even all if broken this was down, the Thetsunamis light is generated67 m above by thesealevel. slides Built mayin have 1835, reached the light- Ire- caseup-stairs or if got the knockeddamage was into induced one. The by windows projected all rocks, broken these in, houseland. originallyAll other had events two date towers from but only1755 one until remains present today. day wouldthe staircase remain carried remarkable away.” events. As for the lighthouse tower the 320 andIn are 1837 backed there by is an documented account of eyewitness a huge wave accounts, : “An oceannews- 375 “lightsAt Blacksod were put Point out several Lighthouse, times, built all the in panes 1864, in there the wastower a wavepaper (there reports, being published no hurricane papers at or the tsunami time) [...] databases. swept over The hugewindows wave were during put ain.” storm The in store 1989 houses that caused“were levelled serious to dam- the thetwo island, tsunami the databases lightkeepers used with are their the families Russian taking Academy refuge of ageground, to the pantries lighthouse. and everything This lighthouse smashed.” is 13 Shem above also describessea level. inSciences’ the tower, Tsunami just in Laboratory time to save Historical their lives, Tsunami when theDatabase roofs Apaving description stones is(flags) given being by a transported: school group “Flags who were were giventorn up a of(RAS the, dwelling2012) and homes the US were National carried Oceanic away and [...].” Atmospheric (The Irish tourand tossedof the lighthouse around like from marbles.” the lightkeeper She finishes Vincent by saying Sweeney: “the 325 TimesAdministration’s, 15/10/1869). National Geophysical Data Center Tsunami 380 “WhenLower station the storm is a came complete to the wreck.” lighthouse On it 25 smashed January every- 1935 EventOn 11 Database March ( 1861NOAA another, 2012). huge The wave catalogue did considerable describes 22 thinganother in storm its path. struck It was the solight strong putting that it it out blew ofaction a barrel (CIL full, damage.storm wave The events, Commissioners 15 tsunamis of Irish and 13 Lights rogue (CIL) wave describe events, of2012 oil). in In the January window of 1987 down and the February hall and of into 1988, the “substan- kitchen. thewith event: Fig. 2 “Ongiving the 11ththeir March locations. 1861 at midday the light room Thetial damage storm flooded was again the whole done by house.” storms” The (CIL wave, 2012 also). knocked of the East tower was struck by the sea smashing 23 panes, downLighthouse a 4 m high photographer granite wall. John Eagle (Eagle, 2012) de- 330 washing3.1 Storm some waves of the lamps down the stairs, and damaging scribes some of the damage that has been done at Eagle Is-

the reflectors with broken glass beyond repair. It must have 385 3.1.2land: “On 1869 one and occasion 1881: aCalf rock Rock, was thrown Co. Cork up the [S2] high cliffs been3.1.1 an 1837, incredible 1861, wave 1894, to 1935,have come 1987, up 1988,133 feet 1989: [40.5 m] of by a severe storm, it smashed the glass and then the tower rock andthe then Mullet a further Peninsula,87 feet Co. [26. Mayo5 m] of [S1] lighthouse tower Onfilled the up 27th with November water. . . . 1881 The doorthe lighthouse had to be at drilled Calf Rock, to let sit-the to cause so much damage”. uatedwater offbefore the it southwestern could be opened.” tip of the in the 335 TheOn Eagle the Island 29th andDecember Blacksod 1894 Point a lighthouses storm “damaged on the Mul- the westGiven of Co. the description, Cork (see Fig. this was 2) wasmost destroyed likely during in a the violent 1861 dwellingslet Peninsula of inthe Co. East Mayo station (see beyond first inset repair of Fig. and2 for also map broke lo- storm.or 1894 The event. tower was completely severed. The Comman- thecation lantern and Fig.glass,3 for put a out picture the light of Eagle and damaged Island) have the beenprotect- hit 390 derAlthough of HMS Salamis we have reported included that these they events had seen here five as men storm on ingbyextreme wall” (CIL). waves Inon a letter multiple written occasions. by one of Eagle the inhabitants Island lies thewaves, rock a who wave had height written of in67 red mis on extraordinary. the remaining It portion is likely of ofjust Eagle off the Island, Mullet Polly peninsula Ryan describes close toto the her continental sister Kate shelf. the thethat lighthouse such a wave “NO height ONE represents HURT WANTthe water TO height LEAVE after THE pro- 340 horrorThe light of what is 67 happened m above seathat level. night Built (Ryan, in 1895). 1835, the She light- and ROCK”.jection at Due the base to the of the the severity lighthouse. of the But weather, even if it this was was nearly the thehouse others originally in her house had two were towers woken but “at only half one past remains two to today. jump two weeks before six men were rescued from the rock by

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Table 1. Legend corresponding to Fig. 2.

Label Event Notes S1 1837, 1861, 1894, 1935, 1987, 1988 and 1989: See inset the Mullet Peninsula, Co. Mayo S2 1869 and 1881: Calf Rock, Co. Cork S3 1839: Night of the Big Wind Not shown (whole country) S4 1864: Valentia, Co. Kerry S5 1877: Railway Lines, Co. Dublin and Co. Wicklow S6 1899: Greenore, Carlingford Lough, Co. Louth S7 1941: Lighthouse, the S8 1945: Rosslare, Co. Wexford S9 1951: Kilkee, Co. Clare S10 1953: the Aran Islands S11 1962: Co. Cork S12 1974: Kilmore, Co. Wexford S13 1979: Fastnet Race S14 1982: Ventry, Co. Kerry S15 1985: Fastnet Rock Lighthouse T1 14 680 BP: the Barra Fan, Peach Slide Off map, see Fig. 1 T2 8200 BP: Storegga Slide Off map, see Fig. 8 T3 1755, 1761, 1941 and 1975: the Lisbon, Portugal, tsunamis See insets T4 1767: The River Liffey, Dublin T5 1841: Kilmore, Co. Wexford T6 1854: Kilmore, Co. Wexford T7 1894: Bay & the Atlantic Locations off map: (Festina Lente and Manhattan, off map) (50◦120 N, −35◦230 W), (51◦260 N, −27◦310 W) T8 1922: , Co. Cork T9 1909: Westport Quay, Co. Mayo See inset T10 1910: Cork, Waterford, Southampton, Jersey, Dublin and Ilfracombe T11 1912: Bray, Co. Wicklow T12 1932: , Co. Donegal R1 1852: Inis Mor,´ the Aran Islands R2 1883: , Co. Cork R3 1899: Kilkee, Co. Clare R4 1914: Iniskeeragh, off Donegal R5 1936: , Co. Louth R6 1972: Mullaghderg, Donegal R7 2004: L.E. Rois´ ´ın, off Donegal coast R8 2006: off , Co. Antrim R9 2006: Ardglass, Co. Down R10 2007: , Co. Clare R11 2007: , Co. Kerry R12 2011: Swanland, off Bardsey Island, the Irish Sea R13 2011: Largest wave recorded in Ireland M4 data buoy M1–M6 Locations of data buoys case or if the damage was induced by projected rocks, these of Co. Cork (see Fig. 2), was destroyed in a violent storm. would remain remarkable events. The tower was completely severed. The Commander of HMS At Blacksod Point Lighthouse, built in 1864, there was a Salamis reported that they had seen five men on the rock who huge wave during a storm in 1989 that caused serious dam- had written in red on the remaining portion of the lighthouse age to the lighthouse. This lighthouse is 13 m above sea “NO ONE HURT WANT TO LEAVE THE ROCK.” Due to level. A description is given by a school group who were the the severity of the weather, it was nearly two weeks be- given a tour of the lighthouse from the lightkeeper Vin- fore six men were rescued from the rock by HMS Seahorse. cent Sweeney: “When the storm came to the lighthouse it Calf Rock lighthouse was originally established in 1866. The smashed everything in its path. It was so strong that it blew lighthouse was 31 m high from ground level to the vane and a barrel full of oil in the window down the hall and into the was made from cast iron plates bolted together. It was hit by kitchen. The storm flooded the whole house.” The wave also a storm on 30 January 1869 which washed away 2.4 m of the knocked down a 4 m high granite wall. balcony (Costeloe, 2000) (see Fig. 4). Strong currents from the north and south rush together 3.1.2 1869 and 1881: Calf Rock, Co. Cork [S2] at Calf Rock, producing a local region of highly agitated sea that makes it extremely dangerous to land on the rock (Harrington, 2000–2001). On 27 November 1881 the lighthouse at Calf Rock, situated off the south-western tip of the Beara Peninsula in the west

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ 8L. O’Brien et al.: Extreme wave events in Ireland O’Brien et al.: Extreme wave events in Ireland 631

“awhich dreadful lingered sea liftedin houses the whole for weeks, brig clear seaweed off the carried ” inland (The Galwaygreat distances Weekly and Advertiser fish found, 19 miles January from 1839). the shore. 430 Bunbury (2005) describes the Night of the Big Wind, in 3.1.4particular 1864: the Valentiaferocity of Harbour, the ocean: Co. “ [...]Kerry the [S4] waves actually broke over the tops of the [...] the ocean Ontossed 26 huge November boulders onto1864, the two cliff lifeboats tops of the experienced Aran Islands.” a “great.Note that . . wave” boulders during moved a trial by in waves Valentia have Harbour, been identified Co. Kerry. on The weather was particularly bad at the time, with force 435 cliffs up to 50 m high on the Aran Islands (Williams, 2010). 10A winds log book and account a “tremendous of a sea that was was running thrown and onto break- a reef ingstates wildly.” that “a The dreaded wave squallis described came “gathering on them, the itself brig about drove a milebroad seaward”, side on a and reef as of it rocks met the [...] lifeboat, the sea “its threw crest her towering off her 25beam feet ends”. [8 m] Theyabove had her, a and lucky overhanging” escape two ( hoursThe Irish later Times when, 12 December 1864). 440 “a dreadful sea lifted the whole brig clear off the reef” (The GalwayThough Weekly this could Advertiser be considered; 19/01/1839). a rogue wave, judging Fig. 4. Calf Rock, off the coast of Cork (www.begleys.com/ from the description given, it is more likely to have been an Fig. 4. Calf Rock, off the coast of Cork Boating%20album.htm). overly animated description of what happened to a particu- (www.begleys.com/Boating%20album.htm) 3.1.4 1864: Valentia Harbour, Co. Kerry [S4] larly small boat in a rough sea. On 26th November 1864, two lifeboats experienced a “great 3.1.5 1877: railway lines, Co. Dublin–Co. Wicklow 3.1.3 1839: O´ıche na Gaoithe Moire´ – [...] wave” during a trial in Valentia harbour, Co. Kerry. [S5] 395 HMS Seahorse.The Night Calf of the Rock Big lighthouse Wind [S3] was originally estab- 445 The weather was particularly bad at the time, with force lished in 1866. The lighthouse was 31 m high from ground In10 winds January and 1877, a “tremendous the train sea line was running between and Kingstown breaking levelThe night to the of vane 6–7 January and was 1839, made now from referred cast iron to as plates “The bolted Night (Dwildly”.un´ Laoghaire) The wave andis described Bray was “gathering “considerably itself about damaged a mile together.of the Big It Wind”, was hit “probably by a storm caused on 30th more January widespread 1869 which dam- byseaward”, recent and floods, as it rains met theand. lifeboat, . . waves” “its ( crestThe Irish towering Times25, washedage in Ireland away than2.4 m any of other the stormbalcony in recent(Costeloe, centuries. 2000). Winds See 25feet January [8 m] 1877).above her, and overhanging” (The Irish Times, 400 Fig.reached 4. hurricane force and between a fifth and a quarter of 450 12/12/1864). allStrong houses currents in Dublin from experienced the north some and southdamage, rush ranging together from at 3.1.6Though 1899: this Greenore, could be Carlingford considered a Lough, rogue wave, Co. Louth judging Calfbroken Rock, windows producing to complete a local destruction” region of highly (see Met.ie/wind agitated sea, from the[S6] description given, it is more likely to have been an that2012 makes, in the it list extremely of References). dangerous to land on the rock (Har- overly animated description of what happened to a particu- rington,The sea 2000-2001). played a big part in the damage caused that night, Inlarly early small January boat in 1899, a rough during sea. a bad storm in Greenore, including 42 shipwrecks (Forsythe et al., 2000). Shields and Carlingford Lough, Co. Louth, a boat trying to enter the

Fitzgerald (1989) describe freak phenomena that were docu- 455 harbour3.1.5 1877: “was Railway unable to Lines, do so, Co. and Dublin in the - Co. severe Wicklow storm 405 3.1.3 1839: O´ıche na Gaoithe Moire´ - The Night of the mented at the time or have survived through oral tradition. A that followed[S5] was lost sight of.” The following day it was Big Wind [S3] rare sea bird was found 90 miles from the sea, herrings were reported that the “waves in the Channel ran mountains found 6 miles inland and it was said that trees 12 miles inland high.In January . . a vessel 1877, had the been train wrecked line between off Holyhead” Kingstown (The (DIrishun´ Thewere night covered of the with 6-7th salty January brine. 1839, Sand now banks referred at to as ‘The TimesLaoghaire), 3 January and Bray 1899 was and “considerably 4 January 1899). damaged by recent NightHarbour, of the Co. Big Donegal, Wind’, were “probably eroded caused and “carts more of widespread sand could floods, rains and [] waves” (The Irish Times, 25/01/1877). damagebe gathered” in Ireland nearly than two anymiles other inland. storm in recent centuries. 3.1.7 1941: Inisheer Lighthouse, the Aran Islands, 410 Winds reached hurricane force and between a fifth and a Furthermore, three acres of bog in Cork between Newmar- 460 3.1.6Galway 1899: Greenore, Bay [S7] Carlingford Lough, Co. Louth quarterket and Kanturkof all houses were movedin Dublin nearly experienced a mile and some across damage, a rapid [S6] rangingriver (likely from to broken be the Riverwindows Dalua to complete that flows destruction” between the (see two During a severe flooding in January 1941, the force of the Met.ie/windtowns). Another in the account list of References). from Delaney (1996) recounts sea seaIn early rolled January a giant 1899, rock, during estimated a bad to storm be 84 in Greenore, tonnes, up Car- on waterThe being sea played carried a big inland part and in the pouring damage down caused the chimneys,that night, thelingford shelving Lough, flat Co. rock Louth, a south-west boat trying of to theenter tower the harbour (Scan- lan, 1993). The platform was 2 m above sea level and wave 415 includingthe smell of 42 salt shipwrecks which lingered (Forsythe in houses et al., for 2000). weeks, Shields seaweed and “was unable to do so, and in the severe storm that followed heights were sufficient to flood the lighthouse, ≥ 5 m above Fitzgeraldcarried inland (1989) great describe distances freak and phenomena fish found that miles were from docu- the 465 was lost sight of”. The following day it was reported that the mentedshore. at the time or have survived through oral tradition. A sea“waves level in (Williams the Channel and ran Hall mountains, 2004). high [...] a vessel had rareBunbury sea bird(2005 was found) describes90 miles the from Night the of sea, the herrings Big Wind, were in been wrecked off Holyhead” (The Irish Times; 03/01/1899 & 3.1.8 1945: Rosslare, Co. Wexford [S8] foundparticular6 miles the inland ferocity and of it the was ocean: said that “[T]he trees 12 wavesmiles actually inland 04/01/1899). 420 werebroke covered over the with tops saltyof the brine. Cliffs Sandof Moher. banks . . atthe Ballyshannon ocean tossed Gales and high tides were experienced in coastal towns harbour,huge boulders Co. Donegal, onto the were cliff erodedtops of and the “cartsAran Islands.” of sand could Note around3.1.7 1941: Ireland Inisheer on 18 Lighthouse, December the1945. Aran A Islands, steamer Gal- was bethat gathered” boulders movednearly bytwo waves miles have inland. been Furthermore, identified on cliffsthree 470 “severelyway battered Bay [S7] before she reached shelter in Rosslare”, acresup to 50of bog m high in Cork on the between Aran Islands Newmarket (Williams and, Kanturk2010). were Co. Wexford. Also an “exceptionally high tide” washed movedA log nearly book accounta mile and of a across ship that a rapid was thrown river (likely onto a to reef be awayDuring part a severe of the flooding cliffs in in Rosslare January Bay 1941 (The the Irishforce Times of the, 425 thestates river that Dalua “a dreaded that flows squall between came the on twothem, towns). the brig Another drove 19sea December rolled a giant 1945). rock, estimated to be 84 tonnes, up on accountbroad side from on Delaney a reef of (1996) rocks. recounts . . the sea sea threw water her being off car- her the shelving flat rock beach south west of the tower (Scan- riedbeam inland ends.” and They pouring had a down lucky the escape chimneys, two hours the smell later of when salt lan, 1993). The platform was 2 m above sea level and wave

www.nat-hazards-earth-syst-sci.net/13/625/2013/ Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 10 O’Brien et al.: Extreme wave events in Ireland

Significant wave height 13th−15th August 1979 (51.37N, −9.6W) 6

5.5

5

4.5

4

(m) 3.5 s H 3

2.5

2

1.5

1 13−08−1979 14−08−1979 15−08−1979 16−08−1979 Date

Fig. 5. Fastnet Rock yachtpals.com/files/news/fastnet-rock-boat.jpg Fig. 7. ECMWF model data every 6 hours from ERA Interim re- analysis: Significant Wave Height in the Irish Sea (51.37N, −9.6W) 10632 L. O’Brien O’Brien et al.:et al. Extreme: Extreme wave wave events events in in Ireland Ireland during the Fastnet Race 1979 disaster 13th-15th August.

Significant wave height 13th−15th August 1979 (51.37N, −9.6W) 6 3.2 Tsunamis 5.5

5

4.5 3.2.1 14,680 BP: The Barra Fan and Peach Slide, off

4 North West coast of Ireland [T1]

(m) 3.5 s H 3 590 A large underwater , called the Peach slide, took

2.5 place on the Barra Fan, about 250 km off the North West

2 coast of Ireland (see Fig. 1 for location). Holmes et al. (1998)

1.5 suggest that four large-scale submarine landslides make up

1 the Peach Slide. 13−08−1979 14−08−1979 15−08−1979 16−08−1979 Date 595 Owen et al. (2010) sampled and analysed cores from the area. They concluded that the Peach 4 debrite, the most re- cent in a series of large scale mass transport deposits, has Fig. 6. Overturned yacht during 1979 race (www.gerry.odonoghue. Fig. 5. Fastnet Rockyachtpals.com/files/news/fastnet-rock-boat.jpg (yachtpals.com/files/news/fastnet-rock- Fig. 7. 6.ECMWF modelOverturned data every yacht 6 hours during from ERA 1979 Interim race re- a minimum age of 14,680 years BP, was formed through a Fig. 5. Fastnet Rock com/images/fastnetNS.jpg). boat.jpg). www.gerry.odonoghue.com/images/fastnetNS.jpganalysis: Significant Wave Height in the Irish Sea (51.37N, −9.6W) combination of blocky and muddy debris flows and affects 2 during the Fastnet Race 1979 disaster 13th-15th August. 600 an area of 700 km . This is about 3/4 the size of Dublin county. 3.1.9 1951: Kilkee, Co. Clare [S9] and sea wall.” The harbour had undergone improvements A landslide of such proportion could very well have gen- only 16 months previously. Local fishermen said the high 3.2 Tsunamis erated a large scale tsunami that would have undoubtedly Damage was caused by a “storm and. . . wave” in Kilkee, Co. tides3.1.14 were 1982: recurring Co. Kerry because [S14] of constant strong winds, and Clare, in December 1951 (The Irish Times, 22 May 1952). reached Irish shores given its location. the3.2.1 islands 14,680 of Inishbofin, BP: The Inisturk BarraFan and Inisturbot and Peach were Slide, cut off off 575 (InThe October IrishNorth Times of West1982, 12 February“hugecoast of waves Ireland 1974). [...] [T1] split open the wreck 3.1.10 1953: the Aran Islands and the Irish Sea [S10] of the Spanish container ship, Ranga” off the cliffs near 605 3.2.2 8,200 BP (before 1950): Storegga slide [T2] 3.1.13Coumeenole 1979: beach, Fastnet in Ventry,Race [S13] Co. Kerry (The Irish Times; A storm in 1953 halted the construction of the slipway at 590 A large underwater landslide, called the Peach slide, took 16/10/1982). The Storegga slide is one of the world’s largest known sub- place on the Barra Fan, about 250 km off the North West Gort Na gCapall on the Aran Islands and also sank the The Fastnet race is a famous offshore yacht race that takes marine landslides and occurred off the west coast of Norway Princess Victoria in the Irish Sea when “the stern gates to placecoast of every Ireland second (see yearFig. 1 in for August location). over Holmes 4–5 days, et al. starting (1998) generating a huge tsunami, see Fig. 8. Recent studies such as 3.1.15 1985: Fastnet Rock Lighthouse [S15] the car deck were forced open in heavy seas”, with the nearsuggest the Islethat of four Wight large-scale in England, submarine rounding landslides the Fastnet make Rock up that from Bryn et al. (2005) estimate that the slide removed loss of 132 people (The Irish Times, 5 June 2003, and BBC 3 offthe the Peach south-west Slide. coast of Ireland and finishing at 610 between 2500 and 3500 km of sediment from the slide scar News, 1 January 1953). 595580 inInOwen1985, England the et al.(see Fastnet (2010) the Rock dashed sampled lighthouse line and inanalysedFig. keeper2). at The coresthe time, 1979 from Dick race the approximately 8,200 years BP. It is thought that inundation Williams and Hall (2004) document eyewitness accounts beganO’Driscoll,area. They on 11 recallsconcluded August, a storm a sunnythat wave the day Peach reaching in calm 4 debrite, waters,as high the asbut the most stormy light re- was as high as 30 m and reached Norway, Shetland, Scotland from Gort Na gCapall. The storm caused the total destruction conditionsandcent crashing in a series put through competitors of large the glass, scale into sendingmass great transport difficulty, the poisonous deposits, resulting vat has ofin and the Faroes. Fig.of the 6.constructionOverturned machinery andyacht a large during number 1979 of mega- race 15mercurya minimum deaths, pouring 24 age boats ofdown lost 14,680 the or abandoned,stairs. years The BP, Fastnet was and aformed total light of stands through 194 out49 a The length of the headwall of the slide scar is 290 km and clasts (up to 2 m in length and 15 m above sea level) were www.gerry.odonoghue.com/images/fastnetNS.jpg ofmcombination above303 boats mean of not sea blocky finishing. level. and He Rescue muddy said that workersdebris suddenly flows picked afterwardsand up affects 140 615 the slide travelled 300 km to the northwest down into the transported so that there was no longer access to the slip- 2 600585 survivorstherean area was of (see a700 great Figs.km calmness5.and This6). is (The about Economist3/4 the, size 18/12/08 of Dublin and Norway Basin, and then more than 500 km beyond that in way for boat launching. Waves reached breaking heights of www.cil.iecounty.Matthew). Sheaha, one of the competitors, said about the the form of a giant turbidity current (Bugge et al., 1988). approximately 12 to 15 m. conditionsA landslide “[a] of lot such has proportion been made could out very about well the have strength gen- oferated the wind. a large . . but scale it was tsunami the sea that state would that have was undoubtedly the real is- 3.1.143.1.11 1982: 1962: Co. Co. KerryCork [S11] [S14] sue.reached The Irish waves shores were. given . . 40–50 its location. ft [∼ 12–15 m] tall and very steep sided, but coming from all kinds of different an- 575 InIn October early March of 1982 1962, “huge storms waves and flooding [...] split across open the the country wreck gles and breaking. It was like being in the middle of mul- ofwere the reported Spanish along container with “a. ship, . . wave Ranga” which off had the flooded cliffs every near 605 3.2.2 8,200 BP (before 1950): Storegga slide [T2] tiple avalanches. Quite extraordinary” (BBC Sport, 9 Au- Coumeenolesea port in the beach, south-east in Ventry, of Ireland.” Co. Kerry Cork was (The worst Irish affected Times; because of its position (The , 9 March 1962, gustThe Storegga2009). A slide report is on one the of exceptional the world’s weather largest known during sub- the 16/10/1982). ´ and The Irish Times, 9 March 1962). Two years later it was racemarine from landslides Met Eireann and occurred (Met.ie-Fastnet off the west, unknown coast) of contains Norway reported that “the Memorial Park in Youghal was almost recordsgenerating of force a huge 10 tsunami, winds in see some Fig. areas 8. Recent with recorded studies such wave as 3.1.15washed 1985: away byFastnet a. . . wave. Rock . .Lighthouse years ago.” [S15] This may be re- heightsthat from of Bryn 7.5 m et off al. the (2005) coast estimate of Waterford, that the and slide a maximum removed of 14.5 m. The report also describes3 how the weather sys- ferring to the 1962 incident (The Irish Times, 12 Septem- 610 between 2500 and 3500 km of sediment from the slide scar tem originated from a depression near Newfoundland late on 580 Inber 1985, 1964). the This Fastnet event Rock could lighthouse alternatively keeper be atclassified the time, Dick as a approximately 8,200 years BP. It is thought that inundation the 11th that moved eastward and started to deepen rapidly O’Driscoll,storm surge. recalls a storm wave reaching as high as the light was as high as 30 m and reached Norway, Shetland, Scotland on the 13th. This turned north-eastwards coming in over and crashing through the glass, sending the poisonous vat of and the Faroes. the south-west of Ireland late on the 13th and centring over mercury3.1.12 pouring 1974: Kilmore, down the Co. stairs. Wexford The Fastnet [S12] light stands 49 The length of the headwall of the slide scar is 290 km and Wexford early on the 14th. It was during this period (13th– m above mean sea level. He said that suddenly afterwards 615 the slide travelled 300 km to the northwest down into the On 11 February 1974, storm waves at Kilmore Quay, Co. 14th) that the worst damage occurred. Records of the wind at 585 there was a great calmness (The Economist, 18/12/08 and Norway Basin, and then more than 500 km beyond that in Wexford, “tore a 35-ft [10.7 m] gap in the new concrete pier the show that south-south-easterly gales www.cil.ie). the form of a giant turbidity current (Bugge et al., 1988).

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ 10L. O’Brien O’Brien et al.: Extremeet al.: Extreme wave events wave in eventsIreland in Ireland 633

Significant wave height 13th−15th August 1979 (51.37N, −9.6W) 6

5.5

5

4.5

4

(m) 3.5 s H 3

2.5

2

1.5

1 13−08−1979 14−08−1979 15−08−1979 16−08−1979 Date

Fig. 7. ECMWF model data every 6 h from ERA-Interim reanalysis: significant wave height in the Irish Sea (51.37◦ N, −9.6◦ W) during Fig. 5. Fastnet Rock yachtpals.com/files/news/fastnet-rock-boat.jpg Fig.the 7. FastnetECMWF Race model 1979 disaster, data every 13–15 6 hoursAugust. from ERA Interim re- analysis: Significant Wave Height in the Irish Sea (51.37N, −9.6W) during the Fastnet Race 1979 disaster 13th-15th August. were recorded ahead of the depression on the evening of the 13th, which became westerly storm force in the early hours 3.2of Tsunamis the 14th and developed into north-westerly gale force winds which eased during the afternoon. Model data from the European Center for Medium-Range 3.2.1Weather 14,680 Forecasts BP: (TheECMWF Barra, 2012 Fan) by and ERA-Interim Peach Slide, reanal- off ysis isNorth shown West in Fig. coast7 (every of Ireland 6 h) on [T1] 13, 14 and 15 Au- gust 1979. The data has been bilinearly interpolated to a lat- Fig. 8. Figure taken from Bryn et al. (2005) showing the location of ◦ ◦ the Storegga submarine slides on the mid-Norway margin. 590 A largeitude/longitude underwater position landslide, of (51.37 calledN, the−9.6 PeachW), which slide, lies took placeapproximately on the Barra 2 km Fan, south about of Fastnet250 km Rock. off The the Northsignificant West wave height peaks at 5.8 m on the morning of the 14th at coast of Ireland (see Fig. 1 for location). Holmes et al. (1998) sonous vat of mercury pouring down the stairs. The Fastnet 6 a.m. (local time). Reanalysis is a process by which a nu- suggest that four large-scale submarine landslides make up light stands 49 m above mean sea level. He said that sud- merical model and observations of many different sorts are the Peach Slide. denly afterwards there was a great calmness (The Economist, combined in an optimal way to produce a best estimate of 595 18 December 2008 and www.cil.ie). Owenthe various et al. atmospheric, (2010) sampled wave and and analysed oceanographic cores parame- from the area. They concluded that the Peach 4 debrite, the most re- ters. The ERA-Interim reanalysis is the latest global atmo- 3.2 Tsunamis centspheric in a seriesreanalysis oflarge produced scale by mass ECMWF. transport deposits, has Fig. 6. Overturned yacht during 1979 race a minimumClearly, age the ofdriving 14,680 force years of this BP, disaster was formed was the through storm a 3.2.1 14 680 BP: the Barra Fan and Peach Slide, off www.gerry.odonoghue.com/images/fastnetNS.jpg combinationthat came in of across blocky the and Atlantic, muddy and debris so most flows of theand waves affects north-west coast of Ireland [T1] 2 600 anencountered area of 700 werekm large. This storm is waves.about 3 However,/4 the size rogue of waves Dublin county.cannot be ruled out given the indications of the significant A large underwater landslide, called the Peach Slide, took ´ Awave landslide heights of of such 5.8–7.5 proportion m (Met Eireann could very and ECMWF) well have and gen- place on the Barra Fan, about 250 km off the north-west coast reports of maximum wave heights approximately twice as of Ireland (see Fig. 1 for location). Holmes et al. (1998) sug- 3.1.14 1982: Co. Kerry [S14] erated a large scale tsunami that would have undoubtedly high 12–15 m (Met Eireann´ and Matthew Sheaha). gest that four large-scale submarine landslides make up the reached Irish shores given its location. Peach Slide. 3.1.14 1982: Co. Kerry [S14] 575 In October of 1982 “huge waves [...] split open the wreck Owen et al. (2010) sampled and analysed cores from the of the Spanish container ship, Ranga” off the cliffs near 605 3.2.2 8,200 BP (before 1950): Storegga slide [T2] area. They concluded that the Peach 4 debrite, the most re- In October of 1982 “huge waves. . . split open the wreck Coumeenole beach, in Ventry, Co. Kerry (The Irish Times; cent in a series of large-scale mass transport deposits, has a Theof Storegga the Spanish slide container is one of ship, the world’sRanga” offlargest the knowncliffs near sub- minimum age of 14 680 yr BP, was formed through a combi- 16/10/1982). Coumeenole Beach, in Ventry, Co. Kerry (The Irish Times, marine landslides and occurred off the west coast of Norway nation of blocky and muddy debris flows and affects an area 16 October 1982). 2 generating a huge tsunami, see Fig. 8. Recent studies such as of 700 km . This is about 3/4 the size of Dublin county. 3.1.15 1985: Fastnet Rock Lighthouse [S15] A landslide of such proportion could very well have gen- that3.1.15 from Bryn 1985: et Fastnet al. (2005) Rock estimate lighthouse that [S15] the slide removed 3 erated a large-scale tsunami that would have undoubtedly 610 between 2500 and 3500 km of sediment from the slide scar reached Irish shores given its location. In 1985, the Fastnet Rock lighthouse keeper at the time, 580 In 1985, the Fastnet Rock lighthouse keeper at the time, Dick approximately 8,200 years BP. It is thought that inundation O’Driscoll, recalls a storm wave reaching as high as the light wasDick as high O’Driscoll, as 30 m recalls and reached a storm Norway, wave reaching Shetland, as highScotland as and crashing through the glass, sending the poisonous vat of andthe the light Faroes. and crashing through the glass, sending the poi- mercury pouring down the stairs. The Fastnet light stands 49 The length of the headwall of the slide scar is 290 km and m above mean sea level. He said that suddenly afterwards 615 thewww.nat-hazards-earth-syst-sci.net/13/625/2013/ slide travelled 300 km to the northwest down into the Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 585 there was a great calmness (The Economist, 18/12/08 and Norway Basin, and then more than 500 km beyond that in www.cil.ie). the form of a giant turbidity current (Bugge et al., 1988). 634 L. O’Brien et al.: Extreme wave events in Ireland

Fig. 9. Petrified forest, Bray, Co. Wicklow. Fig. 10. Petrified forest, Bray, Co. Wicklow.

3.2.2 8200 BP (before 1950): Storegga Slide [T2] ating another tsunami. This event was not as devastating as The Storegga Slide is one of the world’s largest known sub- the 1755 one, but the tsunami again travelled great distances, marine landslides and occurred off the west coast of Norway the furthest recorded being Barbados. Both tsunamis reached generating a huge tsunami (see Fig. 8). Recent studies such Irish shores (NOAA Tsunami Events Database). as that from Bryn et al. (2005) estimate that the slide removed An eyewitness account is given in Berninghausen (1968) between 2500 and 3500 km3 of sediment from the slide scar from Kinsale, Co. Cork, on 1 November 1755: “Between 3 approximately 8200 yr BP. It is thought that inundation was and 4 p.m., the water came over the quay with such violence as high as 30 m and reached Norway, Shetland, Scotland and as to throw many people down.” In a letter from L. Nicola (on the Faroes. the same day) (Nicola, 1755–1756), Kinsale is described in The length of the headwall of the slide scar is 290 km, and more detail: “[A] large body of water suddenly poured into the slide travelled 300 km to the north-west down into the this harbour, with such rapidity that it broke the cables of Norway Basin, and then more than 500 km beyond that in two sloops, each moor’d with two anchors, and of several the form of a giant turbidity current (Bugge et al., 1988). boats. . . carried up, then down, the harbour [...]. This was re- Rising sea level at the end of the last ice age cut Britain peated several times [...]. The bottom of the harbour. . . was and Ireland off from the rest of Europe. Fossilised trees that much altered. . . the perpendicular rise of the water. . . was five once stood on dry land can been seen in Bray, Co. Wicklow, feet and a half [1.7 m]. . . and I am told it was much higher at at low water (see Figs. 9 and 10). Numerous trigger mecha- the market-place, which it overflowed [...]. The successive nisms of the Storegga Slide related to the melting of the ice risings and fallings of the water continued about ten minutes sheets have been proposed, including sediment overloading [...]. By different accounts received here the water was af- and earthquakes, while gas hydrate melting is likely to have fected in the same manner along the coast, to the westward influenced sliding locally (Bryn et al., 2005). of this harbour, and it is reported, that, about nine o’clock in No reports of evidence of the tsunami reaching Irish shores the morning a shock of an was felt at Cork.” have been found. However, given the location and size of the Larkin (2010) relays the effects of the tsunami on In- wave, it is possible that remnants of the wave reached Ire- nishannon, Co. Cork. The wave rushed up the estuary of land, although Scotland would have sheltered Ireland some- the Bandon River towards the town, the original bridge be- what. ing completely destroyed. He says that the Bandon River was originally navigable from Kinsale up as far as Bandon 3.2.3 1755, 1761, 1941 and 1975: the Lisbon, Portugal, town, but the tsunami permanently lowered the depth of the tsunamis [T3] river (see third inset in Fig. 2). Larkin says that the course of the river allegedly changed through Innishannon Village, On 1 November 1755 a magnitude 11 MMI (see Ap- and the sand deposits at The Warren in and the pendix A) earthquake struck Lisbon, Portugal, and created a sand dunes at Long Strand at are a result of the tsunami that devastated Lisbon. The tsunami travelled to sur- tsunami. rounding European and African countries but also reached Traditionally, the 1755 tsunami is thought to have sepa- countries as far as Canada and Cuba. In 1761 a magnitude rated the small island of Aughinish, on the southern shores 9 MMI (see Appendix A) earthquake struck Lisbon gener- of from Co. Clare, and the Norman castle of

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ 12 O’Brien et al.: Extreme wave events in Ireland L. O’Brien et al.: Extreme wave events in Ireland 635 coast, to the westward of this harbour, and it is reported, that, Corranrue supposedly became victim of the same inundation 660 about nine o’clock in the morning a shock of an earthquake (The Irish Times, 14 January 2005). Further south, the sand was felt at Cork.” dunes at Barleycove in Co. Cork are believed to be a direct re- Larkin (2010) relays the effects of the tsunami on Innis- sult of the tsunami (cork-guide.ie, 2012). Also, it is believed hannon, Co. Cork. The wave rushed up the estuary of that the in Galway was damaged by the 1755 the Bandon river towards the town, the original bridge be- tsunami (galwaytourism.ie, 2012). 665 ing completely destroyed. He says that the Bandon River The 1761 tsunami occurred late on the 30th of March, was originally navigable from Kinsale up as far as Bandon and five run-up (the run-up is the tsunami amplitude when town, but the tsunami permanently lowered the depth of the it hits the shoreline and is defined as the wave height above river (see third inset in Fig. 2). Larkin says that the course the mean high tide level) observations in Ireland at Kin- ofsale, the Waterford, river allegedly Dungarvan changed and through Newross Innishannon are listed in villageNOAA 670 andTsunami the sand Events deposits Database at The for Warren the following in Rosscarbery day (see and third the sandand dunes fourth at insets Long of Strand Fig. 2 atto Castlefreke locate these are places). a result In of Kin- the tsunami.sale, a run-up of 0.6 m was recorded: “[A]bout six o’clock p.m.Traditionally near dead the low 1755 water, tsunami the tide is thought rose suddenly to have on sepa- the ratedstrand, the about small two island feet of [0 Aughinish,.6 m] higher on than the it southern was, and shores went 675 ofout Galway again in Bay the fromspace Co.of four Clare minutes and with the Norman great force, castle which of Corranruewas repeated supposedly several became times; but victim the of first the was same the inundation greatest.” Fig. 11. Figure taken taken from from Dawson Dawson et et al. al., (2000). 2000. Hydrograph Hydrograph show- show- (TheIn Waterford, Irish Times Co.; 14/01/2005). Waterford, Further “[t]he sea south, advanced the sand 30 dunes feet inging the the arrival arrival of the 1941 Portuguese tsunami tsunami at at Newlyn, Newlyn, Cornwall at[9 Barleycove.1 m] on the in Co.shore.” Cork In are Dungarvan, believed to Co. be aWaterford, direct result “five of (solid(solid line)line), and and the the tide tide gauges gauges on previous and and subsequent subsequent days days theebbings tsunami and (cork-guide.ie, flowings of the 2012). sea Also, were it observed is believed between that the 4 (dashed(dashed lines) (source(source: Proudman Proudman Oceanographic Oceanographic Institute) Institute). 680 Spanishand 9 p.m.” arch At in Ross, Galway [Newross] was damaged Co. Wexford, by the 1755 “a violent tsunami ag- (galwaytourism.ie,itation of the river 2012). there took place about 7 p.m.” In Carrick, 3.2.6 1854: Kilmore, Co. Wexford [T6] Co.The Antrim, 1761 tsunami a run-up occurred of 1.2 m late was on observed: the 30th March “[T]he and waters five Tsunami Database (1.8 m) and in the NOAA Tsunami Events run-upof the (the river run-up Suir rose is the about tsunami 4 p.m. amplitude to extentof when 4 feet it hits [1.2 the m] The RAS Historical Tsunami Database lists a questionable Database (1.5 m) . There is no known cause for this and it is shorelinein the space and of is 5 defined min.” Also as the in Cork wave City, height Co. above Cork, the an earth-mean tsunami in Kilmore, Co. Wexford, on 16 September 1854 listed as a questionable tsunami and very doubful tsunami in 685 highquake tide was level) felt observations for less than in a Irelandminute; at “between Kinsale, the Waterford, gates of (currently listed as 1864 but to be corrected). 715 each database respectively. However, it is interesting to note Dungarvanthe city it and was Newross more violent are listed than in that NOAA of November Tsunami Events 1755” At the harbour in Kilmore, Mr. William Campbell gives that a run up of 1.5 m is also listed on the NOAA Tsunami Database(Borlase, the1830 following). day (see third and fourth insets of an account of the “Phenomenon at Kilmore” as he saw it Database in Ostend, Belgium on the same day. Fig.More 2 to locaterecently, these in 1941 places). and In 1975, Kinsale, there a were run-up earthquakes of 0.6 m from his boat: “[O]n a sudden I heard a mighty rush of water isin recorded, the same area “about near six Portugal o’clock and P.M. small near tsunami dead waves low water, were against the back of a pier, and in a moment it came sweeping 3.2.5 1841: Kilmore, Co. Wexford [T5] 690 therecorded tide rose by suddenly the on the at strand, Newlyn, about located two on feet the [0 south-.6 m] round the pier head, full three feet [1.5 m] high and abreast higherwest corner than it of was, England. and went The tide out gauge again records in the space from Dawson of four [...]. The inner dock was crowded with the small sailing craft The RAS Historical Tsunami Database lists a questionable minuteset al. (2000 with) aregreat shown force, in which Figs. 11 wasand repeated12. several times; of the place, and quite dry [...]. In less than five minutes ev- but the first was the greatest”. In Waterford, Co. Waterford, 720 tsunamiery boat on was 12th afloat September and wehad 1841 high at Kilmore, water. In Co. five Wexford. minutes 3.2.4 1767: the River Liffey, Dublin [T4] “The sea advanced 30 feet [9.1 m] on the shore”. In Dun- Themore cause the water is unknown. ebbed again to the lowest spring tide. This 695 garvan, Co. Waterford, “five ebbings and flowings of the sea was repeated seven times in the course of two hours and a- wereRun-up observed observations between on 4 and the 9 River p.m.”. Liffey, At Ross, Dublin, [Newross] on 5 3.2.6 1854: Kilmore, Co. Wexford [T6] September 1767 are listed both in the RAS Historical half. St. Patrick’s Bridge was alternately dry and covered to Co Wexford, “a violent agitation of the river there took place Tsunami Database (1.8 m) and in the NOAA Tsunami Events the extent of a mile. At the same time the sea was not by about 7 p.m.” In Carrick, Co. Antrim, a run-up of 1.2 m was The RAS Historical Tsunami Database lists a questionable Database (1.5 m). There is no known cause for this, and it is any means rough or heaving. . . two different currents running observed, “the waters of the river Suir rose about 4 P.M. to tsunami in Kilmore, Co. Wexford on 16th September 1854 listed as a questionable tsunami and very doubtful tsunami in parallel and counter currents to these quite visible,. . . and the 700 extent of 4 feet [1.2 m] in the space of 5 min.” Also in Cork 725 (currently listed as 1864 but to be corrected). each database, respectively. However, it is interesting to note intervening colour of the original green hue, was station- city, Co. Cork, an earthquake was felt for less than a minute: At the harbour in Kilmore Mr. William Campbell gives an that a run-up of 1.5 m is also listed on the NOAA Tsunami ary [...]. I can only compare the current to the opening of “between the gates of the city it was more violent than that account of the “Phenomenon at Kilmore” as he saw it from Database in Ostend, Belgium, on the same day. a sluice gate [...]. Had the occurrence taken place at the pe- of November 1755” (Borlase, 1830). hisriod boat: of high “on water, a sudden the I result heard would a mighty have rush been of the water complete against the back of a pier, and in a moment it came sweeping round 3.2.5More 1841:recently, Kilmore, in 1941 Co. and Wexford 1975, there [T5] were earthquakes overflow of the land in the district and consequent immense 705 in the same area near Portugal and small tsunami waves were 730 theloss.” pier The head, journalist full three interviewing feet [1.5 Mr.m] high Campbell and abreast concludes, [...]. recordedThe RAS by Historical the tide gauge Tsunami at Newlyn, Database located lists a on questionable the south The“We inner have dock often was heard crowded old people with of the that small place sailing say that craft on of westtsunami corner on 12of England.September The 1841 tide at Kilmore, gauge records Co. Wexford. from Daw- The thethe place, Sunday and after quite Lisbon dry [...]. was destroyed In less than by five the earthquakeminutes every of soncause et al. is unknown.(2000) are shown in Figs 11 and 12. boat1 November was afloat 1755, and we the had day high being water. remarkably In five minutes fine, the more sea theat Kilmore water ebbed suddenly again rose to andthe lowest fell in likespring manner” tide. This (Nation was, 3.2.4 1767: The River Liffey, Dublin [T4] 735 repeated30 September seven 1854). times in the course of two hours and a-half. St. Patrick’s Bridge was alternately dry and covered to the 710 Run up observations on the River Liffey, Dublin, on the extent of a mile. At the same time the sea was not by any 5th September 1767 are listed both in the RAS Historical means rough or heaving [...] two different currents running

www.nat-hazards-earth-syst-sci.net/13/625/2013/ Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 O’Brien et al.: Extreme wave events in Ireland 13 636 L. O’Brien et al.: Extreme wave events in Ireland

the wave was heard some time before it was seen and then 760 seemed to be about 40 feet [∼ 12 m] high. The vessel never rose to it but was literally submerged for a time” (Berning- hausen, 1968). A newspaper report described the incident as follows: “During a gale [...] the SS Diamond was attacked by a 765 tremendous sea, which carried away her davits and boats, also the upper bridge, and smashed the lower bridge, broke the funnel, and carried© 1895 Nature away Publishing Group the mizzen mast. The cargo Fig.shifted, 13. Tabletaken and the from vesselStromeyer was(1895 thrown). on her beam ends. One of the sea men was washed overboard, but was thrown back 770 on deck by a wave. The captain was thrown down [...].” ing.Also, “She was another seen bysteamer the crew that of was the S.S. comingDiamond in atbefore the same time the wavewent struck missing. the latter, “She but was not seen afterwards. by the It crew is feared of the she Diamond has gonebefore down the with wave all struck hands” the(The latter, Irish Times but not, 24afterwards. Novem- It is ber 1894).feared she has gone down with all hands” (The Irish Times, Stromeyer (1895) gives information about the wave en- 775 24/11/1894). countered by the S.S. Diamond and waves encountered by two otherStromeyer , the (1895)Festina gives Lente and information the Manhattan about, in the the wave en- Northcountered Atlantic within by the a few Diamond days of and each waves other (see encountered Fig. 13). by two TheotherFestina ships, Lente encounter the Festina is described Lente and as follows: the Manhattan, “A steep in the sea fellNorth on board Atlantic from within both sides.” a few For days the Manhattan of each, other “[t]he (see Fig. 780sea was13). high, The but Festina fairly true Lente until encounter a mountainous is described wave broke as follows: on board“A steep from sea N. W.” fell on board from both sides”. For the Manhat- Thetan: locations “The sea of the was three high, ships but and fairly the volcano true until are shown a mountainous in Fig.wave14. broke Usingon the board locations from and N. times W. ”. of the three events, an estimate of the period of waves travelling between the The locations of the three ships and the volcano are shown Fig. 12. Figure taken from Dawson et al. (2000). Hydrograph show- ships was calculated using deep water wave theory. If the Fig.ing 12. theFigure arrivaltaken of the 1975from Portuguese Dawson et tsunami al., 2000. at Newlyn, Hydrograph Cornwall show- 785wavein was Fig. a 14.tsunami, Using we the should locations use the and shallow times water of the wave three events, ing(solid the arrival line), and of the the 1975 tide gauges Portuguese on subsequent tsunami days at Newlyn, (dashed Cornwall lines) theory,an but estimate the results of the obtained period below of waves with deep travelling water wave between the (solid(source: line) Proudman and the tide Oceanographic gauges on Institute). subsequent days (dashed lines) theoryships arewas quite calculated realistic. The using difference deep inwater distance wavedx theory.and If the (source Proudman Oceanographic Institute) timewavedt iswas deduced a tsunami, from Fig. we13 should. The group use the velocity shallow of the water wave wavetheory is then but taken the as resultscg = dx/dt obtained, and thebelow period with is given deep by water wave T = ( π/g)c 3.2.7 1894: Galway Bay [T7] 790 theory4 areg. quite realistic. The difference in distance dx and Atime wavedt travellingis deduced between from the Fig.Festina 13. Lente Theand group the velocityMan- of the parallelOn 21 and November counter 1894, currents a 12 to m these wave quite hit Galway visible, Bay. [...] It and hattanwavewould is then have taken a period as ofc approximately= dx/dt and 15the s, period which is given by is listed as a probable tsunami caused by a volcano in the characteristic of a storm wave.g However a wave travelling 740 the intervening colour of the original green hue, was station- T = (4π/g)c . middle of the North Atlantic on the NOAA Tsunami Events between these twog ships and the S.S. Diamond in Galway ary [...]. I can only compare the current to the opening of a Database (this is why we list it in this section), but we have Bay wouldA wave need travelling to have a between period of the 4–5 Festina s. Therefore, Lente andit is the Man- sluice gate [...]. Had the occurrence taken place at the pe- not found any evidence for the presence of this volcano. An 795probablehattan that would the Festina have Lente a periodand theof approximatelyManhattan encoun-15 seconds, riodeyewitness of high water, account the reads result “the would ship ‘S.S. haveDiamond been the’ lying-to complete teredwhich the same is characteristic wave system generated of a storm by wave. a storm, However but the a wave overflowawaiting of daylight the land to in enter the port, district reported and consequent that the wave immense was S.S.travellingDiamond encountered between these a different two ships wave. and We the discard Diamond the in Gal- 745 loss.”heard The some journalist time before interviewing it was seen Mr. and Campbell then seemed concludes: to be possibilityway Bay of a would tsunami need generated to have by the a period volcanic of eruption4 − 5 seconds. “Weabout have 40 often feet [∼ heard12 m] old high. people The vessel of that never place rose say to it that but on for atTherefore, least two reasons: it is probable (i) we found that the no evidence Festina Lentefor theand vol- the Man- was literally submerged for a time” (Berninghausen, 1968). canic eruption, and (ii) a tsunami is barely felt in the middle the Sunday after Lisbon was destroyed by the earthquake of 800 hattan encountered the same wave system generated by a 1st NovemberA newspaper 1755, report the day described being remarkably the incident fine, as the fol- sea of thestorm ocean. but the Diamond encountered a different wave. We lows: “During a gale. . . the S.S. Diamond was attacked by at Kilmore suddenly rose and fell in like manner” (Nation discard the possibility of a tsunami generated by the volcanic a tremendous sea, which carried away her davits and boats, 3.2.8 1922: Ballycotton, Co. Cork [T8] 750 (Newspaper), 30/09/1854). also the upper bridge, and smashed the lower bridge, broke eruption for at least two reasons: (i) we found no evidence the funnel, and carried away the mizzen mast. The cargo A largefor wavethe volcanic caught out eruption; a farmer (ii) and a two tsunami labourers is barely as they felt in the 3.2.7shifted, 1894: and Galwaythe vessel Bay was [T7] thrown on her beam ends. One 805weremiddle planting of potatoes the ocean. 250 yards from the shore near Bally- of the sea men was washed overboard, but was thrown back cotton, Co. Cork, in early May 1922: “[A] huge. . . wave sud- Onon the deck 21st by November a wave. The 1894, captain a was12 thrownm wave down.” hit Galway Also, an- Bay. denly3.2.8 came on 1922: them, Ballycotton, overwhelming Co. the farmer, Cork [T8] and making it Itother is listed steamer as athat probable was coming tsunami in at the caused same time by awent volcano miss- in a narrow escape for the others. The wave receded as quickly the middle of the North Atlantic on the NOAA Tsunami A large wave caught out a farmer and two labourers as they 755 EventsNat. Hazards Database Earth (this Syst. is why Sci., we 13, list 625– it648 in, this 2013 section) but were www.nat-hazards-earth-syst-sci.net/13/625/2013/ planting potatoes 250 yards from the shore near Bal- we have not found any evidence for the presence of this vol- lycotton, Co. Cork, in early May 1922: “a huge [...] wave cano. An eyewitness account reads “[...] the ship ‘S.S. Dia- 810 suddenly came on them, overwhelming the farmer, and mak- mond’ lying-to awaiting daylight to enter port, reported that ing it a narrow escape for the others. The wave receded as 14 O’Brien et al.: Extreme wave events in Ireland

Eyewitness Lyons (1993) describes how he and his brother and father were travelling by horse and cart when they heard a “loud rumbling noise like thunder”. The road flooded, split- ting the wall and the sea was “throwing these concrete blocks 840 as if they were pebbles”. They later learned that “the entire road all the way to Rosbeg was strewn with large pieces of broken sea-wall.” About a hundred yards down the road they were ploughing “through four feet [1.2 m] of water which had now reached the body of the cart.” Further down the road 845 “there was a sudden surge of water” that lifted them in the air and threw them against the wall. Afterwards the road was Fig. 13. Table taken from Stromeyer (1895). L. O’Brien et al.: Extreme wave events in Irelandcovered with pieces of broken sea wall, timber and the con- 637 tents of the local hotel. Boats also lay on the road and thou- sands of tons of sugar and treacle were destroyed along with cle were destroyed along with many other food and clothing 850 many other food and clothing supplies. He notes that there supplies. He notes that there was a dead calm everywhere was a dead calm everywhere and unusually the “telegraph and unusually the “telegraph wires leading towards the town wires leading towards the town were making a peculiar kind were making a peculiar kind of high, screaming noise.” This of high, screaming noise.” This description could imply that description could imply that the source of the wave was at- the source of the wave was atmospheric, like that of the 2011 mospheric, like that of the 2011 tsunami on the south-west 855 tsunami on the South West coast of England when people coast of England when people described there being a dead described there being a dead calm, and their hair standing on calm, and their hair standing on end. end. Another interesting feature of the location of this event is Fig. 14. MapMap from from Google Google Earth Earth showing locations of the three Another interesting feature of the location of this event is ships for for the the 1894 1894 events events and and the the volcano. volcano. The The coordinates coordinates of the of that it occurred in Clew Bay. A multitude of sunken drum- ◦ 0 00 ◦ 0 00 that it occurred in Clew Bay. A multitude of sunken drum- theships ships are: are: FestinaFestina Lente Lente (50(50 12 0012 N,00 35N, 23 35 0023 W),00 ManhattanW), Manhat- (51 lins (glacial ) are a distinctive characteristic of this ◦ 0 00 ◦ 0 00 ◦ 0 00 860 lins (glacial landforms) are a distictive characteristic of this tan26 00(51 N,26 2700 31N, 00 27 W),31 Diamond00 W), and (53 S.S. 09 00Diamond N, 09 52(53 0009 W).00 TheN, area. This may have funnelled and amplified the wave that ◦ 0 00 ◦ area. This may have funnelled and amplified the wave that 09volcano52 00 activityW). The is in volcano the vicinity activity of 49 is N, in 34.5 the W. vicinity of 49 N, inundated Westport Quay in 1909. See the second inset of 34.5◦ W. inundated Westport Quay in 1909. See second inset of Fig. 2 forFig. a2 satellitefor a view of view Clew of Bay. Clew Bay. 1910: Cork and Waterford [T10] In mid December of asquickly it came, as leavingit came, the leaving men in the a statemen inof wonder”a state of (The wonder” Irish 865 19101910: a Cork “Tragedy and at Waterford Sea” occurred [T10] resulting in the loss of five Times(The Irish, 3 May Times 1922).; 03/05/1922). vessels. The ships that left Waterford and Cork on the 15th Interestingly, an earthquake in Puerto Rico is documented DecemberIn mid-December 1910 were of 1910 reported a “Tragedy as lost. at They Sea” were occurred headed re- − 815 on NOAA NOAA Tsunami Tsunami Events Events Database Database at at 8:24 8:24pm p.m. (GMT (GMT− 4) tosulting Jersey, in Dublinthe loss and of five Southampton. vessels. The It ships was that suggested left Water- that on 2the May 2nd 1922. May 1922. A questionable A questionable tsunami tsunami due to due an earth- to an theyford had and been Cork “enveloped on 15 December by a [...] 1910 wave were off reported the South-West as lost. quakeearthquake is logged is logged with withtwo documented two documented run-up runup observations. observa- 870 coast”They were after headed a message to Jersey, was sent Dublin to Dublin and Southampton. that “a [...] Itwave was Thetions. first The is an first eyewitness is an eyewitness report of a report train of of three a train waves of three with hadsuggested been observed that theyby had the been people “enveloped at the Tuskar by a. . . Lighthouse,wave off the awaves period with of 45a period min at of Vieques 45 minutes Island, at Vieques Puerto Rico, Island, followed Puerto WexfordSouth-West on coast”the night after of athe message 15th December”. was sent to On Dublin the 16th that 820 eightRico, hours followed later eight by a hourssimilar later train by of a smaller similar waves. train of The smaller sec- “a“a. gale . . wave raged had with been exceptional observed fury”by the off people the South at the coast Tuskar of ondwaves. was Thea water second height was of a0. water64 m from height a tide of 0 gauge.64 m in from Texas a IrelandLighthouse, (The IrishWexford Times on, 25/02/1911). the night of the 15 December.” On overtide-gauge 3000 km in Texas away. over Maybe3000 thiskm was away. the Maybe source thisof the was wave the 875 theHaslett 16th “a and gale Bryant raged (2009) with exceptionalgive details offury” the off major the storm south insource Cork. of Using the wave ETOPO1 in Cork. bathymetry Using ETOPO1 data, the bathymetry average water data, thatcoast occurred of Ireland on (The the 16th Irish December Times, 25 February1910, accompanied 1911). by depththe average along thewater line depth connecting along the Puerto line Rico connecting and Ballycot- Puerto a uniqueHaslett large and Bryantwave that(2009 struck) give Ilfracombe details of in the North major Devon. storm 825 tonRico was and calculated Ballycotton as was3.553 calculated km using as 1003.553 points.km Assumingusing 100 Theythat occurred claim that on the 16 wave December possessed 1910, tsunami accompanied characteristics by a thatpoints. the wave Assuming travelled that across the wave the Atlantictravelled√ over across this the depth, At- andunique could large possible wave that have struck been Ilfracombe a meteo-tsunami in North related Devon. to −1 it would have an average speed of gh = 186.6 m s ac- 880 the excitation of large-amplitude seiches in a semi enclosed √lantic over this depth, it would have an average speed of They claim that the wave possessed tsunami characteristics cordinggh = 186 to shallow.6 m/s according water theory. to shallow Given that water the theory. distance Given from waterand could body, possibly such as havethe Bristol been aChannel. meteo-tsunami The locations related of to Puertothat the Rico distance to Ballycotton from Puerto is Rico approximately to Ballycotton 6217 is approxi- km, the thethe excitationorigins (Waterford of large-amplitude and Cork) seiches and the in supposed a semi-enclosed desti- 830 tsunamimately 6 would,217 km, have the reached tsunami Ballycotton would have after reached about Ballycot- 9 h and nationswater body, of the such 5 vessels as the in Bristol December Channel. 1910 The (Dublin, locations Jersey of 15ton min, after so about at approximately9 hrs and 15 mins, 09:40 so the at following approximately morning. 09:40 andthe origins Southampton) (Waterford are shown and Cork) in Fig. and 2. the Ilfracombe, supposed destina-Devon, the following morning. 885 wheretions of an the unusally 5 vessels large in wave December struck, 1910 is also (Dublin, indicated. Jersey and 3.2.9 Meteo-tsunamis and storm surges Southampton)1912: Bray, are Co. shown Wicklow in Fig. [T11]2. Ilfracombe,Local residents Devon, in whereBray, 3.2.9 Meteo-tsunamis and storm surges Co.an unusually Wicklow large believed wave they struck, experienced is also indicated. a tsunami on the 6th 1909: Westport Quay, Co. Mayo [T9] March 1912. They reported that the sea rose, flooding the Es- 1909: Westport Quay, Co. Mayo [T9] In November 1909 planade 6 feet (1.8 m), and the weather was not stormy at the 835 Inan November unusual wave 1909 and an flooding unusual occurredwave and in flooding Westport occurred Quay. 890 time.1912: They Bray, also Co. mention Wicklow feeling [T11] a shock like an earthquake, in Westport Quay. Eyewitness Lyons (1993) describes how he and his brother and father were travelling by horse and Local residents in Bray, Co. Wicklow, believed they expe- cart when they heard a “loud rumbling noise like thunder.” rienced a tsunami on 6 March 1912. They reported that The road flooded, splitting the wall, and the sea was “throw- the sea rose, flooding the esplanade 6 feet (1.8 m), and the ing these concrete blocks as if they were pebbles.” They weather was not stormy at the time. They also mention feel- later learned that “the entire road all the way to Rosbeg was ing a shock like an earthquake, which some attributed to the strewn with large pieces of broken sea-wall.” About a hun- force of the waves against the sea wall. Also, it was said dred yards down the road they were ploughing “through four that along Bray Head “a huge mass of large paving stones feet [1.2 m] of water which had now reached the body of the was lifted up and carried on the walk to a height of three cart.” Further down the road “there was a sudden surge of or four feet [1.1–1.5 m]” (The Irish Times, 20 March 1912 water” that lifted them in the air and threw them against the and 22 March 1912). However, a report a few days later (The wall. Afterwards the road was covered with pieces of broken Irish Times, 25 March 1912) put the event down to “an ex- sea wall, timber and the contents of the local hotel. Boats traordinarily high tide”, and although the heavy seas flooded also lay on the road and thousands of tons of sugar and trea- the road, it said “[n]one of the cottages was flooded and

www.nat-hazards-earth-syst-sci.net/13/625/2013/ Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 638 L. O’Brien et al.: Extreme wave events in Ireland the biggest paving-stone that was shifted by the seas was not heavier than 5lb weight.” It also reported that the fish- ermen “attributed the flood to the high spring tide”, although a telegram from respected seismologist Rev. Wm. O’Leary of Mungret College, Limerick is relayed in the same article indicating that an earthquake did in fact occur: “One small earthquake at 24 p.m. [midnight], 7th. Tremor. Storm experi- enced [between the] 5th to 8th would equally mask small dis- turbance.” This indicates that there was an earthquake around the time of the flooding which may suggest a tsunami, but there is also evidence of a strong storm which could have caused a storm surge (The Irish Times, 25 March 1912). Fur- thermore, there is no record of any seismic activity around this time on Dublin Institute of Advance Studies earthquake Fig. 15. L.E. Rois´ ´ın (source: www.military.ie/naval-service/fleet/ listings (DIAS, 2012). Finally, we emphasize that there is no large-patrol-vessel/le-roisin-p-51). tide data available for Bray in 1912! This event could be an example of an interaction between a tsunami and a storm surge. 3.3.3 1899: Kilkee, Co. Clare [R3] In July 1899 a “Marvellous Escape From Drowning” oc- 3.2.10 1932: Inishowen, Co. Donegal, and Strabrega curred in Kilkee, Co. Clare, when a wave came out of Bay [T12] nowhere. While a man was teaching his son how to swim, “an enormous. . . wave burst with extraordinary force over the Multiple incidents occurred during “Violent Gales” across adjoining rocks, completely submerging the two bathers in the country in January 1932. In particular Inishowen, Co. a cauldron of foaming water, and whirling them round for a Donegal, experienced a “tremendous storm of wind and rain considerable distance.” Another man was also washed off the [...]; the tide. . . rose to a height not seen for very many years.” rock (The Irish Times, 22 July 1899). In Strabrega Bay the tide was like a “tidal wave which ran in- land high up the surrounding fields, into the farm yards, and 3.3.4 1914: Iniskeeragh, off Donegal [R4] even into the farm houses.” Then the wind dropped suddenly, and within 45 min it was calm (The Irish Times, 15 Jan- In February 1914, the small island of Iniskeeragh, lying off uary 1932). , off the Donegal coast, was hit by a huge wave. Reports said the island was “almost entirely submerged” and 3.3 Rogue waves that the residents heard a roar of water before it arrived. There was severe loss of property (The Irish Times, 20 Febru- 3.3.1 1852: Inis Mor,´ the Aran Islands [R1] ary 1914).

On 16 August 1852 a “Melancholy Accident” occurred at 3.3.5 1936: Dundalk, Co. Louth [R5] the Glasson Rocks on Inis Mor´ resulting in the loss of fifteen lives. A group were fishing on the cliffs when “ a sudden On 4 July 1936 two unusually large waves were observed in swell of the Atlantic swept them off, when they perished be- Dundalk, Co. Louth. Local fishermen first thought they saw fore the slightest assistance could be rendered” (The Galway “whales, approaching rapidly up the seaway”, but it turned Vindicator, 18 August 1852). out to be “immense waves, which rushed at great speed” and made a “clean sweep on both banks” (The Irish Times, 3.3.2 1883: Youghal [R2] 6 July 1936).

In April 1883, “An Extraordinary Occurrence” occurred in 3.3.6 1972: Donegal [R6] Youghal Harbour, Co. Cork, when the water was “sud- denly agitated in a most violent manner for about ten min- On 13 July 1972, four schoolgirls were swept away by “a utes. . . accompanied by a roaring sound.” It was a localized freak wave” at Mullaghderg Beach, near Kincaslagh, Done- event since some of the boats “appeared to have been struck gal. A group of 200 school children had been swimming with by a furious hurricane”, but others a few hundred yards away their teachers at the beach which is “normally regarded lo- were not affected. Afterwards the water calmed down, and it cally as reasonably safe but subject to fast moving waters and was described by a sailor as “one of the most extraordinary dangerous undercurrents under certain tidal and wind condi- things he has ever seen in the harbour [...]” (The Irish Times, tions.” The incident occurred when two of the teachers got 28 April 1883). into trouble and the children “formed a human chain” to try

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ L. O’Brien et al.: Extreme wave events in Ireland 639

O’Brien et al.: Extreme wave events in Ireland 17 Fig. 17. Rathlin O’Birne Island.

Fig. 16. The approximate location of L.E. Rois´ ´ın (boat) when it re- ceived the pan-pan broadcast, and the location of Rathlin O’Birne Island close to where L.E. Rois´ ´ın encountered the two waves. to help them but the wave broke the chain and swept the four girls away (The Irish Times, 14 July 1972).1

3.3.7 2004: L.E. Rois´ ´ın, off the coast of Donegal [R7]

On 5 October 2004, an Irish naval ship was hit by two rogue waves on its way to help a Canadian submarine, HMS Chicoutimi, that got into trouble when a serious fire broke Fig. 18. M4 data buoy significant wave height readings on 5 Octo- out. L.E. Rois´ ´ın (see Fig. 15) had taken shelter in Donegal Fig.ber 18. 2004M4 from datawww.marine.ie/home/publicationsdata/data/IMOS/ buoy significant wave height readings on the 5th Fig. 20. M4 data buoy maximum gust readings on the 5th October Bay near due to bad weather when it responded to a OctoberIMOSDBObservations.htm 2004 from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. . 2004 from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. pan-pan broadcast. See Figs. 16 and 17 for location. Captain Lt. Cdr. Terence Ward gave an eyewitness account for the purpose of this research. There was a gale of about force 8 cident (see Figs. 18 and 19). However, it also recorded max- to 9 and a heavy swell with waves approximately 3 to 4 m. imum gusts of up to 47 knots (see Fig. 20). The ECMWF global wave model (ECMWF) estimates sig- As they came around Rathlin O’Birne Island, the ship began The ECMWF global wave model (ECMWF, 2012) es- nificant wave heights of ≤ 2.43 m using bilinear interpolation to climb a very large wave, pivoted on the crest, then fell timates a significant wave height of ≤ 3.6 m at Rathlin to a position on the coast off Ardglass (54.26N, −5.6W). down the other side and plunged into a second large wave. O’Birne Island (54.66◦ N, −8.8◦ W) on 5 October that year,

About one third of the ship was submerged for a time, until which is in line with the described by Lt. Cdr. Ter- 1050 3.3.10 2007: Doonbeg, Co. Clare [R10] the buoyancy pushed it back up through the wave. The two ence Ward. A 10–12 m wave definitely indicates a rogue waves were approximately 10–12 m with a very short period. wave in these circumstances. Possible causes may have been A Moldovan man died while fishing in the Blue Pool area The windscreen wipers were all detached, the flare cracked the strong gusts of wind or the tidal streams and bathymetry of Doonbeg, Co. Clare, on the 1st July 2007. It is thought and a piece of the deck broke away allowing water to get in. around Rathlin O’Birne Island (a possibility suggested by that a wave swept him off the rocks. The coastguard said that A decision was made to turn back for repairs. Lt. Cdr. Ward). weather conditions were bad at the time but that the area is Furthermore, an inquiry concluded that the fire on board the HMS Chicoutimi was caused by a wave, much higher 3.3.8 2006: off Portrush, Co. Antrim [R8] 1055 “notorious for freak waves” (RTE News; 01/07/07). than the four meter sea state, that overflowed the tower which Information from the M3, M4 and M6 databuoys (see Fig. was open during repairs (Murphy et al., 2004). On 21 May 2006 a 15 foot fishing boat “was capsized and to- 2) show that the significant wave height that day was ≤ 4.7 Fig. 19. The M4 data buoy located about 75 km off the north-west tally destroyedM4 data buoy by a freak wind speedwave” readings just off theon the coast 5th of October Portrush, 2004 m with the largest value occurring at the M3. Also the maxi- from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. coast of Ireland (see Fig. 2) recorded significant wave heights Co. Antrim. The unpredicted wave overturned the boat, trap- mum recorded values for wind speed and maximum gusts at of ≤ 4.5 m and wind speeds ≤ 27 knots on the day of the in- ping the fisherman underneath it. Luckily he managed to free 1060 the three buoys considered occurred at M3 with values of 20 himself and was close enough to swim to the shore without knots and 29 knots respectively. 1An anonymous referee suggested that the wave might have injury (The Belfast Telegraph, 22 May 2006, and Coleraine 1030 be noted that Portrush lies at the more exposed North coast been created by a . Times, 25 May 2006). of Ireland and the M2 databuoy is in a more sheltered posi- 3.3.11 2007: Valentia Island, Co. Kerry [R11] tion in the Irish sea. Additionally, the ECMWF global wave www.nat-hazards-earth-syst-sci.net/13/625/2013/model (ECMWF) Nat. Hazards estimates Earth the Syst. significant Sci., 13, wave 625–648 height, 2013 that On the 13th July 2007, internationally renowned rock day to be ≤ 1.42 m using bilinear interpolation to a position climber Michael Reardon was swept away by a large wave 1065 1035 off the coast of Portrush (55.38N, −6.67W). If the waves as he stood on the ledge of an inlet around the bottom of were approximately 1.5 m on the day of the incident, then a Wireless Point merely 15 feet [4.6 m] above the Atlantic. 3 to 4.5 m wave could be considered a rogue wave. After Reardon finished his two cliff climbs, his photographer who was with him at the time said: he “was waiting on an 3.3.9 2006: Ardglass, Co. Down [R9] algae-covered platform for the big swells to pass by so that 1070 he could walk back over to me on the opposite side of the A man was swept away by a wave as he leaned on pier wall inlet. A rogue wave came into the inlet and curved right- 1040 at the harbour talking to local men in Ardglass, Co. Down, wards as it crashed into Mike. He tried to stabilize himself on the 2nd December 2006. The wave “swept over the pier on the platform but the water was too powerful and sucked and dragged him into the waves”. The wind was particularly him in. The current pulled Mike out 150-plus meters in mere bad at the time, blowing with gale force in Ardglass (The1075 seconds” (Los Angeles Times, 19/07/07). Irish Independent; 4/12/2006). Gusts of up to 64.8 knots and The M3 databuoy (see Fig. 2) recorded significant wave 1045 storms were reported across the country caused by a deep heights ≤ 2.5 m on this day with wind speeds ≤ 18 knots depression from the Atlantic (The Irish Times; 4/12/2006). and maximum gusts of up to 25 knots. Therefore the waves O’Brien et al.: Extreme wave events in Ireland 17

Fig. 18. M4 data buoy significant wave height readings on the 5th Fig. 20. M4 data buoy maximum gust readings on the 5th October October 2004 from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. 2004 from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm.

64018 L. O’Brien et al.: Extreme wave events in Ireland O’Brien et al.: Extreme wave events in Ireland

Significant and max wave height 26th−27th Nov 2011 (52.76N −5.00W) The ECMWF global wave model (ECMWF) estimates sig- 10 H s ≤ 2.43 H nificant wave heights of m using bilinear interpolation 9 max

to a position on the coast off Ardglass (54.26N, −5.6W). 8

7

1050 3.3.10 2007: Doonbeg, Co. Clare [R10] 6

5 Height (m) A Moldovan man died while fishing in the Blue Pool area 4 of Doonbeg, Co. Clare, on the 1st July 2007. It is thought 3 that a wave swept him off the rocks. The coastguard said that 2

1 weather conditions were bad at the time but that the area is 00−00 06−00 12−00 18−00 00−00 06−00 12−00 18−00 Time HH−MM 1055 “notorious for freak waves” (RTE News; 01/07/07). Fig. 21. Swanland rescue (image from BBC news, 11 Decem- Fig.Information 21. Swanland from Rescue, the M3, image M4 from and BBC M6 databuoys news, 11/12/11 (see Fig.Fig. 23. ECMWF global wave model 6 hourly output of significant ber 2011 www.bbc.co.uk/news/uk-16055328). Fig. 19. M4 data buoy wind speed readings on 5 Octo- www.bbc.co.uk/news/uk-160553282) show that the significant wave height that day was ≤ 4.7and maximum wave heights, H and H respectively, bilinearly Fig. 19. M4 data buoy wind speed readings on the 5th October 2004 s max O’Brien et al.: Extreme wave events in Irelandber 2004 from www.marine.ie/home/publicationsdata/data/IMOS/ 17 m with the largest value occurring at the M3. Also the maxi-interpolated to a location in the region where the Swanland sank fromIMOSDBObservations.htmwww.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. . mum recorded values for wind speed and maximum gusts at(52.76N, −5.00W) on the 26-27th November 2011. and dragged him into the waves.” The wind was particularly 1060 the three buoys considered occurred at M3 with values of 20 bad at the time, blowing with gale force in Ardglass (The Irishknots Independent and 29 knots, 4 December respectively. 2006). Gusts of up to 64.8 1030 be noted that Portrush lies at the more exposed North coast knots and storms were reported across the country caused by and the largest recorded was 4.8 m. It also recorded wind 3.3.11 2007: Valentia Island, Co. Kerry [R11] of Ireland and the M2 databuoy is in a more sheltered posi- a deep depression from the Atlantic (The Irish Times, 4 De-1100 speeds and maximum gusts of ≤ 28.7 knots and ≤ 42.35 tion in the Irish sea. Additionally, the ECMWF global wave cember 2006). knots respectively. model (ECMWF) estimates the significant wave height that OnThe the ECMWF 13th global July 2007, wave model internationally (ECMWF, renowned2012) esti- rock The ECMWF global wave model (ECMWF) estimates sig- day to be ≤ 1.42 m using bilinear interpolation to a position matesclimber significant Michael wave Reardon heights was of ≤ swept2.43 m away using by bilinear a large in- wave ◦ nificant wave heights of ≤ 4.57 m over the 26-27th Novem- 1065 terpolation to a position on the coast off Ardglass (54.26 N, 1035 off the coast of Portrush (55.38N, −6.67W). If the waves as he stood on the ledge of an inlet around the bottom ofber 2011 when bilinearly interpolated to a position in the re- −5.6◦ W). were approximately 1.5 m on the day of the incident, then a Wireless Point merely 15 feet [4.6 m] above the Atlantic.1105 gion where the Swanland sank (52.76N, −5.00W). However, 3 to 4.5 m wave could be considered a rogue wave. After Reardon finished his two cliff climbs, his photographerthe model also gives a maximum wave height output and this 3.3.10 2007: Doonbeg, Co. Clare [R10] who was with him at the time said: he “was waiting on angave values up to 9.55 m. The largest values of both signif- algae-covered platform for the big swells to pass by so thaticant and maximum wave heights occur at midnight on the 3.3.9 2006: Ardglass, Co. Down [R9] A Moldovan man died while fishing in the Blue Pool area of 1070 26th, and considering it is a 6 hourly output, this coincides Fig.Doonbeg,he 22. couldSwanland, Co. walk Clare, image back on from 1over July BBC to 2007. me news. onIt is the thought opposite that a side wave of the 1110 well with the time the wave struck at approximately 2:00 am AFig. man 20. wasM4 swept data away buoy bymaximum a wave gust as he readings leaned on on 5pier Octo- wall sweptinlet. him A off rogue the wave rocks. came The coastguard into the inlet said and that curved weather right- Fig. 18. M4 data buoy significant wave height readings on the 5th on the 27th (see Fig. 23). 1040 atFig.ber the 20. 2004 harbourM4 from data talkingwww.marine.ie/home/publicationsdata/data/IMOS/ buoy maximum to local gustmen readings in Ardglass, on the Co. 5th October Down, conditionswards as were it crashed bad at the into time Mike. but that He thetried area to is stabilize “notorious himself October 2004 from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. on2004IMOSDBObservations.htm the from 2ndwww.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm December 2006.. The wave “swept over. the pier foron freak the waves” platform (RTE but News the water, 1 July was 2007). too powerful and sucked were probably not very high at the time, so a 5 m wave could 3.3.13 2011: Largest wave ever recorded in Ireland and dragged him into the waves”. The wind was particularly himInformation in. The current from the pulled M3, Mike M4 and out M6150-plus data buoys meters (see in mere 1080 be considered a rogue wave. [R13] bad at the time, blowing with gale force in Ardglass (The1075 Fig.seconds”2) show (Los that Angeles the significant Times, 19/07/07).wave height that day was IrishThe Independent M2 data buoy; 4/12/2006). located in Gusts the ofIrish up Sea to 64 (see.8 knots Fig. 2 and) ≤ 4.7The m, withM3 databuoy the largest (see value Fig. occurring 2) recorded at the significant M3. Also, wave recordedThe ECMWF significant global wave wave heights model≤ (ECMWF)1.5 m on 21 estimates May 2006. sig- 3.3.12 2011: Cargo Ship, Swanland, The Irish Sea On the 13th December 2011 the M4 weather buoy registered 1045 storms were reported across the country caused by a deep theheights maximum≤ 2 recorded.5 m on values this day for with wind wind speed speeds and maximum≤ 18 knots [R12] 1115 a 20.4 m wave (see Fig. 24) in a sea state with a signif- nificantFurthermore, wave heights the M2 of recorded≤ 2.43 m wind using speeds bilinear of interpolation≤ 22 knots gusts at the three buoys considered occurred at M3 with val- depression from the Atlantic (The Irish Times; 4/12/2006). and maximum gusts of up to 25 knots. Therefore the wavesicant wave height of 12.97 m. The M4 is located 75 km towith a position maximum on the gusts coast of ≤ off29 Ardglass knots. This (54 suggests.26N, − that5.6W). there ues of 20 knots and 29 knots, respectively. were not gale force winds on the given day. However, it On the 27th November 2011, the 81 m cargo ship, Swan- north of on the north west coast of Ireland (see land loaded with 3000 tonnes of limestone sank in heavy Fig. 2). Since this is an hourly observation we cannot tell 1050 3.3.10should be 2007: noted Doonbeg, that Portrush Co. lies Clare at the [R10] more exposed north 3.3.11 2007: Valentia Island, Co. Kerry [R11] coast of Ireland and the M2 data buoy is in a more sheltered1085 seas in the Irish Sea after she was struck by “an enormous exactly what happened leading up to this huge wave or after- wave”, rolled and broke her back (see Figs 21 and 22).1120 wards. This information cannot be analysed until the full set Aposition Moldovan in the man Irish died Sea. while Additionally, fishing in the the ECMWF Blue Pool global area On 13 July 2007, internationally renowned rock climber The Swanland sank off Bardsey Island about 16 km west of of data is retrieved from the buoy which is only done twice ofwave Doonbeg, model (Co.ECMWF Clare,, 2012 on the) estimates 1st July the 2007. significant It is thought wave Michael Reardon was swept away by a large wave as he the Lleyn peninsula, North Wales at approximately 2:20 am a year. However, it could be useful in determining how the thatheight a wave that sweptday to him be ≤ off1.42 the m rocks. using Thebilinear coastguard interpolation said that to stood on the ledge of an inlet around the bottom of Wire- ◦ − ◦ (lessBBC Point News merely; 27/11/11). 15 feet The [4. wave6 m] above was reported the Atlantic. to be 15 Afterm wave developed and whether or not it could be considered weathera position conditions off the coast were of bad Portrush at the (55 time.38 butN, that6.67 theW). area If is the waves were approximately 1.5 m on the day of the in-1090 (RAF,Reardon 2011). finished There his are two only cliff two climbs, known his survivors photographer from who the a rogue wave. Since the weather buoy network is relatively 1055 “notorious for freak waves” (RTE News; 01/07/07). cident, then a 3 to 4.5 m wave could be considered a rogue eightwas with originally him at on the board time the said ship. he “was waiting on an algae-1125 new (November 2000), it is likely that this is not the largest wave.Information from the M3, M4 and M6 databuoys (see Fig. coveredThe closest platform Irish for databuoy the big swells to the to Swanlandpass by so thatwhen he it could was wave that has developed in Irish waters. 2) show that the significant wave height that day was ≤ 4.7 hitwalk is back the M2 over which to me is on positioned the opposite northwest side of (see the Fig. inlet. 2) A In fact, on the 11th November 2010 the Belmullet Wave Fig. 19. M4 data buoy wind speed readings on the 5th October 2004 m3.3.9 with the 2006: largest Ardglass, value occurring Co. Down at [R9] the M3. Also the maxi- ofrogue the wave incident. came intoIt recorded the inlet significant and curved wave rightwards heights as of it Buoy, owned by the Sustainable Energy Authority of Ireland from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm. mum recorded values for wind speed and maximum gusts1095 at onlycrashed≤ 3 into.2 m Mike. over theHe 26th-27thtried to stabilize November himself 2011. on theThe plat- M5 with access provided through the Marine Institute, recorded 1060 theA threeman was buoys swept considered away by occurred a wave atas M3 he leaned with values on a pierof 20 databuoyform but the which water lies was southwest too powerful of the and incident sucked recorded him in. sig-The1130 some extremely high maximum wave height values. Consid- knotswall andat the29 harbourknots respectively. talking to local men in Ardglass, Co. nificantcurrent wavepulled heights Mike outof ≤ 150-plus4.6 m over meters the same in mere period. seconds” How- ering the zero down-crossing (trough-crest measurement) in- Down, on 2 December 2006. The wave “swept over the pier ever,(Los Angeles the M2 also Times recorded, 19 July maximum 2007). wave heights (hourly) stead of the zero up-crossing (crest-trough as the Marine In- 1030 be noted that Portrush lies at the more exposed North coast of Ireland and the M2 databuoy is in a more sheltered posi- 3.3.11 2007: Valentia Island, Co. Kerry [R11] tion in the Irish sea. Additionally, the ECMWF global wave Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ model (ECMWF) estimates the significant wave height that On the 13th July 2007, internationally renowned rock day to be ≤ 1.42 m using bilinear interpolation to a position climber Michael Reardon was swept away by a large wave 1065 1035 off the coast of Portrush (55.38N, −6.67W). If the waves as he stood on the ledge of an inlet around the bottom of were approximately 1.5 m on the day of the incident, then a Wireless Point merely 15 feet [4.6 m] above the Atlantic. 3 to 4.5 m wave could be considered a rogue wave. After Reardon finished his two cliff climbs, his photographer who was with him at the time said: he “was waiting on an 3.3.9 2006: Ardglass, Co. Down [R9] algae-covered platform for the big swells to pass by so that 1070 he could walk back over to me on the opposite side of the A man was swept away by a wave as he leaned on pier wall inlet. A rogue wave came into the inlet and curved right- 1040 at the harbour talking to local men in Ardglass, Co. Down, wards as it crashed into Mike. He tried to stabilize himself on the 2nd December 2006. The wave “swept over the pier on the platform but the water was too powerful and sucked and dragged him into the waves”. The wind was particularly him in. The current pulled Mike out 150-plus meters in mere bad at the time, blowing with gale force in Ardglass (The1075 seconds” (Los Angeles Times, 19/07/07). Irish Independent; 4/12/2006). Gusts of up to 64.8 knots and The M3 databuoy (see Fig. 2) recorded significant wave 1045 storms were reported across the country caused by a deep heights ≤ 2.5 m on this day with wind speeds ≤ 18 knots depression from the Atlantic (The Irish Times; 4/12/2006). and maximum gusts of up to 25 knots. Therefore the waves 18 O’Brien et al.: Extreme wave events in Ireland

Significant and max wave height 26th−27th Nov 2011 (52.76N −5.00W) 10 H s H 9 max

8

7

6

5 Height (m)

4

3

2

1 00−00 06−00 12−00 18−00 00−00 06−00 12−00 18−00 Time HH−MM

Fig. 21. Swanland Rescue, image from BBC news, 11/12/11 Fig. 23. ECMWF global wave model 6 hourly output of significant 18www.bbc.co.uk/news/uk-16055328 and maximum O’Brien wave heights,et al.:H Extremes and Hmax waverespectively, events bilinearly in Ireland L. O’Brien et al.: Extreme wave events in Irelandinterpolated to a location in the region where the Swanland 641 sank (52.76N, −5.00W) on the 26-27th November 2011. Significant and max wave height 26th−27th Nov 2011 (52.76N −5.00W) 10 H s H 9 max

and8 the largest recorded was 4.8 m. It also recorded wind

1100 speeds7 and maximum gusts of ≤ 28.7 knots and ≤ 42.35 knots respectively. 6 The ECMWF global wave model (ECMWF) estimates sig- 5 nificantHeight (m) wave heights of ≤ 4.57 m over the 26-27th Novem- ber4 2011 when bilinearly interpolated to a position in the re- 1105 gion3 where the Swanland sank (52.76N, −5.00W). However, the2 model also gives a maximum wave height output and this

gave1 values up to 9.55 m. The largest values of both signif- 00−00 06−00 12−00 18−00 00−00 06−00 12−00 18−00 icant and maximum waveTime heights HH−MM occur at midnight on the Fig. 22. Swanland (image from BBC news). 26th, and considering it is a 6 hourly output, this coincides Fig. 22. Swanland, image from BBC news. O’BrienFig. 23. ECMWFet al.: global Extreme wave model wave 6-hourly events output in Ireland of significant 19 1110 well with the time the wave struck at approximately 2:00 am Fig. 21. Swanland Rescue, image from BBC news, 11/12/11 Fig. 23.andECMWF maximum waveglobal heights, waveH models and H6maxhourly, respectively, output of bilinearly significant interpolatedon the 27th to (see a location Fig. 23). in the region where the Swanland sank www.bbc.co.uk/news/uk-16055328 and maximum wave heights, Hs and Hmax respectively, bilinearly (52.76◦ N, −5.00◦ W) on 26–27 November 2011. wereThe probably M3 data not buoy very (see high Fig. at the2) recordedtime, so a significant5 m wave could waveinterpolated3.3.13 to 2011: a location Largest in the wave region ever where recorded the Swanland in Ireland sank − 1080 beheights considered≤ 2.5 m a rogueon this wave. day with wind speeds ≤ 18 knots and(52.76N, 5.00W)[R13] on the 26-27th November 2011. maximum gusts of up to 25 knots. Therefore, the waves were 3.3.12probably 2011: not very Cargo high at Ship, the time, Swanland, so a 5 m The wave Irish could Sea be On the 13th December 2011 the M4 weather buoy registered considered[R12] a rogue wave. 1115 a 20.4 m wave (see Fig. 24) in a sea state with a signif- and theicant largest wave height recorded of 12 was.97 m.4.8 Them. M4 It also is located recorded75 km wind On the 27th November 2011, the 81 m cargo ship, Swan- north of Belmullet on the north west coast of Ireland (see 1100 speeds and maximum gusts of ≤ 28.7 knots and ≤ 42.35 land3.3.12 loaded 2011: with Cargo3000 Ship,tonnesSwanland of limestone, the Irish sank Sea in [R12] heavy Fig. 2). Since this is an hourly observation we cannot tell knots respectively. 1085 seas in the Irish Sea after she was struck by “an enormous exactly what happened leading up to this huge wave or after- wave”,On 27 rolledNovember and broke2011, herthe back81 m (see cargo Figs ship, 21Swanland and 22).1120Thewards. ECMWF This information global wave cannot model be analysed (ECMWF) until estimates the full set sig- Theloaded Swanland with 3000 sank tonnes off Bardsey of limestone Island sank about in 16 heavy km west seas ofinnificantof data wave is retrieved heights from of ≤ the4.57 buoym which over the is only 26-27th done twice Novem- the Lleyn Irish Sea peninsula, after she North was Wales struck at by approximately “an enormous 2:20 wave”, amber 2011a year. when However, bilinearly it could interpolated be useful in to determining a position how in the re- (BBC News; 27/11/11). The wave was reported to be 15 m wave developed and whether or not it could be considered rolled and broke her back (see Figs. 21 and 22). The1105Swan-gion where the Swanland sank (52.76N, −5.00W). However, 1090 (RAF,land sank 2011). off BardseyThere are Island only two about known 16 km survivors west of fromthe Ll theynˆ the modela rogue also wave. gives Since a maximum the weather wave buoy networkheight output is relatively and this eight originally on board the ship. 1125 new (November 2000), it is likely that this is not the largest Peninsula, North Wales, at approximately 2:20 a.m. (BBCgave values up to 9.55 m. The largest values of both signif- NewsThe, 27 closest November Irish databuoy 11). The waveto the was Swanland reported when to be it 15 was m wave that has developed in Irish waters. Fig. 26. Aileen’s wave from www.cliffsofmoher.ie icantFig. and 24. maximumMarine Institute’s wave data heights for maximum occur waveat midnight height at M4 on the hit(RAF is, the2011 M2). There which are is onlypositioned two known northwest survivors (see from Fig. the 2) weatherIn fact, buoy on on the 13/12/11. 11th November Retrieved 2010 from thewww.marine.ie/home/ Belmullet Wave Fig. 22. Swanland,ofeight the image originally incident. from on BBC Itboard recorded news. the ship. significant wave heights of26th,publicationsdata/data/IMOS/IMOSDBObservations.htmBuoy, and consideringowned by the Sustainable it is a 6 hourly Energy output, Authority this. of Ireland coincides 1095 onlyThe≤ closest3.2 m over Irish the data 26th-27th buoy to the NovemberSwanland 2011.when The1110 it was M5wellwith access the time provided the wave through struck the Marine at approximately Institute, recorded 2:00 am Fig. 24. Marine Institute’s data for maximum wave databuoyhit is the which M2, which lies southwest is positioned of the north-west incident recorded (see Fig. sig-2)1130 some extremely high maximum wave height values. Consid- on theheight 27th at (see M4 Fig. weather 23). buoy on 13/12/11. Retrieved from nificantof the incident. wave heights It recorded of ≤ 4. significant6 m over the wave same heights period. of How- only 3.3.13ering the 2011: zero down-crossing largest wave ever (trough-crest recorded measurement) in Ireland [R13] in- ever,≤ . the M2 also recorded maximum wave heights (hourly) www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htmstead of the zero up-crossing (crest-trough as the. Marine In- were probably not3 2 very m over high the at 2–27 the Novembertime, so a 2011.5 m wave The M5 could data buoy,3.3.13 2011: Largest wave ever recorded in Ireland which lies south-west of the incident, recorded significant On 13 December 2011 the M4 weather buoy registered a 1080 be consideredwave a rogue heights wave. of ≤ 4.6 m over the same period. However, the 20.4[R13] m wave (see Fig. 24) in a sea state with a significant M2 also recorded maximum wave heights (hourly), and the wave height of 12.97 m. The M4 is located 75 km north of 3.3.12 2011:largest Cargo recorded Ship, was Swanland, 4.8 m. It also recorded The Irish wind speedsSea andOn theBelmullet 13th December on the north-west 2011 the coast M4 of weather Ireland buoy (see Fig. registered2). ≤ ≤ [R12]maximum gusts of 28.7 knots and 42.35 knots, respec-1115 a 20.Since4 m thiswave is an(see hourly Fig. observation, 24) in a seawe cannot state with tell exactly a signif- tively. icantwhat wave happened height leading of 12. up97 tom. this The huge M4 wave is or located afterwards.75 km On the 27th NovemberThe ECMWF 2011, global the 81 wavem model cargo (ECMWF ship, Swan-, 2012) es-northThis of Belmullet information on cannot the be north analysed west until coast the of full Ireland set of (see timates significant wave heights of ≤ 4.57 m over the 26– data is retrieved from the buoy which is only done twice a Fig. 27. The Cliffs of Moher from www.cliffsofmoher.ie land loaded with27 November3000 tonnes 2011 of when limestone bilinearly sank interpolated in heavy to a po-Fig.year. 2). SinceHowever, this it is could an hourly be useful observation in determining we how cannot the tell ◦ 1085 seas in the Irishsition Sea in after the region she was where struck the Swanland by “an enormoussank (52.76 N,exactlywave what developed happened and whetherleading or up not to itthis could huge be wave considered or after- ◦ wave”, rolled− and5.00 brokeW). However, her back the model (see alsoFigs gives 21 a and maximum 22).1120 wavewards.a rogue This wave. information Since the cannot weather be buoy analysed network until is relatively the full set The Swanlandheight sank output,off Bardsey and this Island gave values about up 16 to km 9.55 west m. The of largestof datanew is (November retrieved 2000), from itthe is likelybuoy that which this is is notonly the done largest twice the Lleyn peninsula,values of North both Walessignificant at approximately and maximum wave 2:20 heights am oc-a year.wave However, that has developed it could in be Irish useful waters. in determining how the 4 Other waves cur at midnight on the 26th, and considering it is a 6-hourly In fact, on 11 November 2010 the Belmullet wave buoy, (BBC News; 27/11/11). The wave was reported to be 15 m output, this coincides well with the time the wave struck atwaveowned developed by the Sustainableand whether Energy or not Authority it could of Ireland, be considered with 1090 (RAF, 2011). There are only two known survivors from the a rogue wave. Since the weather buoy network is relatively approximately 2 a.m. on the 27th (see Fig. 23). access provided through the Marine Institute, recorded some 1140 4.1 Surf Waves eight originally on board the ship. 1125 new (November 2000), it is likely that this is not the largest The closestwww.nat-hazards-earth-syst-sci.net/13/625/2013/ Irish databuoy to the Swanland when it was wave that has Nat. developed Hazards in Earth Irish Syst. waters. Sci., 13, 625–648, 2013 hit is the M2 which is positioned northwest (see Fig. 2) In fact, on the 11th November 2010 the Belmullet Wave As an island exposed on the west coast to the Atlantic, Ire- of the incident. It recorded significant wave heights of Buoy, owned by the Sustainable Energy Authority of Ireland land boasts some of the best big wave/tow-in surfing in Eu- 1095 only ≤ 3.2 m over the 26th-27th November 2011. The M5 with access provided through the Marine Institute, recorded rope. Although surfing in Ireland is still a relatively recent databuoy which lies southwest of the incident recorded sig-1130 some extremely high maximum wave height values. Consid- development, it is attracting an international group of surfers. nificant wave heights of ≤ 4.6 m over the same period. How- ering the zero down-crossing (trough-crest measurement) in- 1145 Some of the most famous big wave spots are listed below. Fig. 25. Marine Institute’s data for the free surface elevation at the ever, the M2 also recorded maximum wave heights (hourly) stead of the zero up-crossing (crest-trough as the Marine In- Two of the most well known surf spots, Mullaghmore, Co. Belmullet Wave Buoy on 11/11/10. Retrieved from Brendan Cahill at HMRC, UCC. The time span of the data shown is 150 s. The Sligo and the Cliffs of Moher, Co. Clare are shown in Fig. 2. surface elevation ranges from −10 m to +15 m. 4.1.1 Aileen’s Wave, off the Cliffs of Moher, Co. Clare

Aileen’s Wave is named after “Aill na Serracht”, meaning 1150 the “Leap of the Foals”. This is Ireland’s most famous big wave surf spot located at The Cliffs of Moher, Co. Clare, stitute does), the extreme wave shown in Fig. 25 (B. Cahill, and has been compared to world famous big waves such as personal communication) can actually be considered to be Teahupoo in Tahiti, Jaws in Maui, and Belharra in France. 1135 23.87 14.12 − −9.75 m ( m ( ) m). Swells usually reach a height of about 8 m, but have been 1155 surfed up to 12 m. The wave is created by a submerged reef. Note that wave buoys may actually be underestimating the The experience level given by yoSurfer (www.yosurfer.com) crests of very large waves so it is likely that larger waves may is ‘pros and nutters’ (see Figs 26 and 27 for images of the actually have occurred in Ireland. wave and its location). O’Brien et al.: Extreme wave events in Ireland 19

Fig. 26. Aileen’s wave from www.cliffsofmoher.ie

Fig. 24. Marine Institute’s data for maximum wave height at M4 weather buoy on 13/12/11. Retrieved from www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm.

O’Brien et al.: Extreme wave events in Ireland 19

642O’Brien et al.: Extreme wave events in Ireland L. O’Brien et al.: Extreme wave events in Ireland 19

Fig. 27. The Cliffs of Moher from www.cliffsofmoher.ie

4 Other waves

1140 4.1 Surf Waves

Fig.As 26. anAileen’s island waveexposed from onwww.cliffsofmoher.ie the west coast to the Atlantic, Ire- land boasts some of the best big wave/tow-in surfing in Eu- Fig. 26. Aileen’s Wavewave from(fromwww.cliffsofmoher.iewww.cliffsofmoher.ie). rope. Although surfing in Ireland is still a relatively recent Fig. 24. Marine Institute’s data for maximum wave Fig.height 25. atMarine M4 Institute’s weather buoy data for on the 13/12/11. free surface Retrieved elevation at from the development, it is attracting an international group of surfers. Belmulletwww.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm wave buoy on 11 November 2010.. Retrieved from Bren-1145 Some of the most famous big wave spots are listed below. Fig. 25.Fig.Marine 24. Institute’sMarine data Institute’s for the free data surface for maximum elevation at wave the danheight Cahill at atM4 HMRC, weather UCC. buoy The on time 13/12/11. span of the Retrieved data shown from is Two of the most well known surf spots, Mullaghmore, Co. Belmullet Wave Buoy on 11/11/10. Retrieved− from Brendan+ Cahill 150www.marine.ie/home/publicationsdata/data/IMOS/IMOSDBObservations.htm s. The surface elevation ranges from 10. m to 15 m. at HMRC, UCC. The time span of the data shown is 150 s. The Sligo and the Cliffs of Moher, Co. Clare are shown in Fig. 2. surface elevation ranges from −10 m to +15 m. extremely high maximum wave height values. Considering 4.1.1 Aileen’s Wave, off the Cliffs of Moher, Co. Clare the zero down-crossing (trough–crest measurement) instead of the zero up-crossing (crest–trough, as the Marine Institute Fig. 27. The Cliffs of Moher (fromfrom www.cliffsofmoher.iewww.cliffsofmoher.ie). does), the extreme wave shown in Fig. 25 (B. Cahill, per- Aileen’s Wave is named after “Aill na Serracht”, meaning sonal communication, 2012) can actually be considered to Fig. 27. The Cliffs of Moher from www.cliffsofmoher.ie 1150 4.1.2the “Leap Prowlers, of the off Foals”. the coast This of Mullaghmore, is Ireland’s most Co. Sligo famous big − be 23.87 m (14.12 m–( 9.75) m). wave surf spot located at The Cliffs of Moher, Co. Clare, Note that wave buoys may actually be underestimating the stitute does), the extreme wave shown in Fig. 25 (B. Cahill, A4and surf Other has spot been waves deemed compared the “Prowlers” to world can famous be found big about waves 3 km such as personalcrests communication) of very large waves can so actuallyit is likely be that considered larger waves to may be off the coast of Mullaghmore, Co. Sligo. Though the exact actually have occurred in Ireland. Teahupoo in Tahiti, Jaws in Maui, and Belharra in France. 1135 23.87 m (14.12 m − (−9.75) m). location4 Other has waves not been revealed by the group of surfers who 1140 4.1Swells Surf usually Waves reach a height of about 8 m, but have been first surfed the wave in 2009 (Neil Britton, Richie Fitzgerald, 1155 Mikesurfed Hamilton up to 12 andm. Aaron The wave Pierce), is they created describe by a the submerged area as reef. 4 Other waves 1140 4.1 Surf Waves Note that wave buoys may actually be underestimating the anAsThe underwater an experience island exposed mountain level on giventhat the westfocuses by coast yoSurfer the to wave the (www.yosurfer.com asAtlantic, it emerges Ire- ) crests4.1 of very Surf large waves waves so it is likely that larger waves may fromlandis ‘pros boasts 40–50 and somem open nutters’ of ocean the best(see into big Figs approximately wave/tow-in 26 and 27 surfing2–3 for m images depths. in Eu- of the actually have occurred in Ireland. However,rope.Aswave an Although island and because its exposed location). surfing this on area in the Ireland is west usually coast is still affected to a the relatively Atlantic, by crossing recent Ire- As an island exposed on the west coast to the Atlantic, Ire- swells,development,land boasts surfers some it must is attractingof thewait best months an big international wave/tow-in at a time forgroup surfing good of surfers. surfing in Eu- land boasts some of the best big wave/tow-in surfing in Eu-1145 conditionsSomerope. Althoughof the (www.northcore-europe.com/surf-videos.html most surfing famous in Irelandbig wave is spotsstill a are relatively listed below. recent). Fig. 25. Marine Institute’s data for the free surface elevation at the rope. Although surfing in Ireland is still a relatively recent de- Twodevelopment,See of Figs. the most28 it isand well attracting29 knownfor images an surf international spots, of the Mullaghmore, wave group and of the surfers. sur- Co. Belmullet Wave Buoy on 11/11/10. Retrieved from Brendan Cahill velopment, it is attracting an international group of surfers.1145 roundingSligoSome and of thearea. the mostCliffs famous of Moher, big Co. wave Clare spots are are shown listed in Fig.below. 2. atFig. HMRC, 25. Marine UCC. Institute’s The time data span for of the the free data surface shown elevation is 150 s. at The the Some of the most famous big wave spots are listed below. Two of the most well known surf spots, Mullaghmore, Co. surfaceBelmullet elevation Wave Buoy ranges on from 11/11/10.−10 m Retrieved to +15 m. from Brendan Cahill 4.1.3 2011: Surf competitions Twoat HMRC, of the UCC. most The well time known span surfof the spots, data shown Mullaghmore, is 150 s. Co.The Sligo and the Cliffs of Moher, Co. Clare are shown in Fig. 2. Sligo, and the Cliffs of Moher, Co. Clare, are shown in Fig. 2. 4.1.1 Aileen’s Wave, off the Cliffs of Moher, Co. Clare surface elevation ranges from −10 m to +15 m. In February 2011, “Tow-in Surf Session”, Ireland’s first 4.1.1 Aileen’s Wave, off the Cliffs of Moher, Co. Clare big4.1.1 wave Aileen’s invitational Wave, surf off contest, the Cliffs was of held Moher, in Mullghmore Co. Clare Co.Aileen’s Sligo. Wave Wave is heights named reached after “Aill 6–7 na m Serracht”, (Irish Independent meaning, 1150 the “Leap of the Foals”. This is Ireland’s most famous big Aileen’s Wave is named after “Aill na Serracht”, meaning the 15 February 2011). waveAileen’s surf Wave spot islocated named at after The Cliffs“Aill na of Serracht”, Moher, Co. meaning Clare, “Leapstitute ofdoes), the Foals.” the extreme This iswave Ireland’s shown most in Fig. famous 25 (B. big Cahill, wave From 23 September to 2 October 2011, the European Surf- 1150 andthe “Leap has been of the compared Foals”. to This world is Ireland’sfamous big most waves famous such big as surf spot, located at the Cliffs of Moher, Co. Clare, and has ing Championships were held in Ireland for the first time, in personal communication) can actually be considered to be Teahupoowave surf inspot Tahiti, located Jaws at inThe Maui, Cliffs and of Belharra Moher, Co. in France. Clare, 1135 been23stitute.87 compared does),14.12 the to extreme world− −9 famous.75 wave shown big waves in Fig. such 25 as (B. Teahupoo Cahill, , Co. Donegal. m ( m ( ) m). Swellsand has usually been compared reach a height to world of famousabout 8 bigm, wavesbut have such been as inpersonal Tahiti, communication)Jaws in Maui, and can Belharra actually in be France. considered Swells to usu- be 1155 4.1.4surfedTeahupoo up 2012 to in12 Big Tahiti,m. waves The Jaws wave in isMaui, created and by Belharra a submerged in France. reef. 1135 ally23.87 reachm (14 a. height12 m − of(− about9.75) 8 m). m, but have been surfed up to Note that wave buoys may actually be underestimating the TheSwells experience usually reach level given a height by yoSurferof about (8www.yosurfer.comm, but have been) 12 m. The wave is created by a submerged reef. The expe- crests of very large waves so it is likely that larger waves may1155 Alissurfed ‘pros Mennie up and to and12 nutters’m. Andrew The (see wave Cotton, Figs is 26created two and of 27by the afor submerged world’s images top of reef. bigthe rience level given by yoSurfer (www.yosurfer.com) is “pros actuallyNote that have wave occurred buoys in may Ireland. actually be underestimating the waveThe experience and surfers, its location). claim level to given have by found yoSurfer two (www.yosurfer.com surf spots off Ire-) and nutters” (see Figs. 26 and 27 for images of the wave and crests of very large waves so it is likely that larger waves may landis ‘pros that and could nutters’ produce (see 120 Figs foot 26 (≈ and37 27m) for waves. images One of is theoff its location). actually have occurred in Ireland. Donegalwave and and its location). the other off Antrim, both crashing down on

Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ 20 O’Brien et al.: Extreme wave events in Ireland

4.1.3 2011: Surf competitions

In February 2011, ‘Tow-in Surf Session’, Ireland’s first big wave invitational surf contest was held in Mullghmore Co. 20L. O’Brien et al.: Extreme wave events in Ireland O’Brien et al.: Extreme wave events in Ireland 643 1175 Sligo. Wave heights reached 6 − 7 m (Irish Independent, 15/02/11). 4.1.3London)From 2011: 23rd suggests September Surf that competitions Cumbre to 2nd October,Vieja Volcano 2011, on the the European island of SurfingLa Palma Championships in the Canary were Islands held may in Ireland experience for the a firstmajor time, vol- inIncanic Bundoran, February slide along 2011, Co. Donegal. its ‘Tow-in western Surf flank Session’, during Ireland’sa future eruption, first big wavepotentially invitational depositing surf 150–500 contest was km3 heldof rock in Mullghmore into the sea. Co.

1175 The Cumbre Vieja has been the6 − most7 activeIrish volcano Independent in the 1180 4.1.4Sligo. 2012 Wave Big heights Waves reached m ( , 15/02/11).Canary Islands for most of the past 125 000 yr; its peak lies ◦ Al2 kmFrom Mennie above 23rd and sea September levelAndrew and Cotton,to has 2nd average October, two ofslopes the 2011, world’sof 15–20 the European top(Ward big waveSurfingand Day surfers, Championships, 2001 claim). Day to et havewere al. (1999 heldfound in) observe twoIreland surf for that spots the the first off volcano time, Ire- Fig. 28. Prowlers, off the coast of Mullaghmore, Co. Sligo landinhas Bundoran, undergone that could Co. producemajor Donegal. structural120 foot changes (≈ 37 m) over waves. the past One sev- is theundergroundcandy.blogspot.com/2010/11/prowlers-irelands- offeral Donegal thousand and years the andother argue off Antrim, that this both is due crashing to stress down pat- unknown-secret-spot.html 11851180 on4.1.4terns rocky associated 2012 reefs Big at with aWaves depth the as growth shallow of a as detachment5 feet [1.5 faultm]. They under saythe that western90% flank.of theWard waves and are Day unridable(2001) but believe they are that wait- a fu- ingAlture Mennie for eruption perfect and near conditions Andrew the summit Cotton, which is might likely two of onlyto the trigger happen world’s a flank twice top fail- big a year.waveure and Al surfers, Mennieconclude claim said that tothat the have he developing looked found for two detachment the surf same spots character- underlies off Ire- Fig. 28. Prowlers, off the coast of Mullaghmore, Fig. 28. Prowlers, off the coast of Mullaghmore, Co. Sligo isticslandmost that inif not Ireland could all of as produce the that western in120 theflank USfoot and ( of≈ theHawaii37 volcano.m) waves. and now They One they sug- is theundergroundcandy.blogspot.com/2010/11/prowlers-irelands-Co. Sligo (from http://blog.surf-prevention.com/2010/11/12/ 1190 haveoffgest Donegal thatfound a wedgewaves and the in shaped Irelandother slide off that Antrim, block are bigger with both dimensions and crashing better down and (15– unknown-secret-spot.htmlal-mennie-prowlers-irlande-surf-casque/). 1185 couldon20 km)rocky be× the reefs(15–25 biggest at km)a depth in× the(1–2 as world. shallow km) may Unfortunately as break5 feet off [1. and5 theym]. create Theywill a notsaymega-tsunami release that 90% theof exactthat the could locations waves propagate are for unridable safety across reasons butthe whole they (Irish are Atlantic Inde- wait- pendentingbasin. for; perfect 09/01/12). conditions which might only happen twice a year.They Al model Mennie the said tsunami that he that looked could for be the generated same character- by such 4.2isticsa 500 Potential in km Ireland3 slide tsunami: as block that in travellingCumbre the US and at Vieja, a Hawaii maximum La and Palma, now speed Ca- they of −1 11951190 have100 mnary found s , Islands wavestravelling in Ireland 60 km that out are to seabigger over and a better period and of could10 min, be from the biggest the western in the flank world. of Unfortunately Cumbre Vieja. they Run-up will Althoughnotheights release of no the the historical exact order locations of records hundreds for exist safety of of meters lateral reasons arecollapses (Irish predicted Inde- of islandpendentaround volcanoes,; neighbouring 09/01/12). around Canary the world Islands evidence within minutes exists of of this the typeslide. of Waves collapse 50–100 in the m form in ofheight scars are on thepredicted seafloor. to These hit the types4.2AfricanPotential of mainlandevents couldtsunami: within pose the Cumbre a threat first hour, of Vieja, catastrophic while La 5–7 Palma, m propor- waves Ca- 12001195 tionsare expected becausenary Islands to of reach the landslide England and and the Spain subsequent within 3–6 tsunami h. La thatPalma such Island collapses blocks would most generate. of the radiation In particular, in this sea north-floor mappingAlthougheasterly arounddirection. no historical the Along Hawaiian records the Islands coastlines exist of in lateral the of Pacific the collapses Americas, Ocean of Fig.Fig. 29. 29.Mullaghmore,Mullaghmore, Co. Sligo. Sligo andislandwaves the volcanoes,up Canary to 25 Islands m around are estimated in the the Atlantic world approximately evidence Ocean have exists 6 h revealed after of this the thesetypelandslide of types collapse occurs of scars in(see andthe Fig. form landslide30). of scars deposits. on the Research seafloor. carried These 3 rocky reefs at a depth as shallow as 5 feet (1.5 m). They say1205 outtypesNote by of Stephen that events for Wardthis could simulation, (UC pose Santa a threat theCruz) slide of and catastrophic volume Simon of Day 500 propor- (UC km London) suggests that Cumbre Vieja Volcano on the island that 90 % of the waves are unridable, but they are waiting for1200 tionswas a because worst case of the estimate landslide of how and much the subsequent material could tsunami po- perfect4.1.2 conditionsProwlers, offwhich the might coast ofonly Mullaghmore, happen twice Co. a year. Sligo Al ofthattentially La such Palma break collapses in away the Canary would from the generate. Islands volcano, may In but experience particular, the block seaa velocity major floor volcanicmappingof 100 m slide saround−1 was along the not its Hawaiian a worst western case Islands flank estimate during in the and a Pacific whenfuture this Oceanerup- ve- Fig.Mennie 29. Mullaghmore, said that he looked Co. Sligo for the same characteristics in Ire- 3 tion,andlocity the potentially is Canary increased Islands depositing to 150 in m the150 s− Atlantic1−the500 maximumkm Oceanof rockhave wave into revealed heights the 1160 landA surf as spot thatdeemed in the US the and “Prowlers” Hawaii, and can nowbe found they about have found 3 km 1210 sea.these types of scars and landslide deposits.2 Research carried wavesoff the in coast Ireland of Mullaghmore, that are bigger Co. and Sligo. better Though and could the be exact the towards America double (Day, 2011). For Ireland, the risk 1205 outThe by CumbreStephen WardVieja (UChas been Santa the Cruz) most and active Simon volcano Day (UC in biggestlocation in has the not world. been Unfortunately, revealed by the they group will of not surfers release who the would be around the south and west coasts, and judging from theLondon) Canary suggests Islands that for Cumbre most of Vieja the past Volcano125000 onyears, the island its exactfirst surfed locations the wave for safety in 2009 reasons (Neil Britton,(Irish Independent Richie Fitzgerald,, 9 Jan- Fig. 30, they would be of the same order as that of England peak lies 2 km above sea level and has average slopes of 4.1.2uaryMike 2012). Hamilton Prowlers, and off Aaron the coast Pierce), of Mullaghmore, they describe the Co. area Sligo as of(5–7 La m). Palma Since in these the Canary type of Islands events occur may experiencevery rarely, a approx- major 15volcanicimately− 20 ° of slide (Ward the along order and Day, ofits thousands western 2001). flank Day of years, etduring al. if(1999) a Cumbre future observe erup- Vieja 1165 an underwater mountain that focuses the wave as it emerges 1215 that the volcano has undergone major structural3 changes in 4.2from Potential 40-50 m open tsunami: ocean Cumbre into approximately Vieja, La Palma, 2-3 m depths. tion,were potentially to experience depositing a major150 collapse− 500 it maykm notof rock happen into for the a 1160 A surf spot deemed the “Prowlers” can be found about 3 km over the past several thousand years and argue that this is due Canary Islands 1210 sea.very long time. However, there is presently no way to accu- offHowever, the coast because of Mullaghmore, this area is Co. usually Sligo. affected Though by the crossing exact torately stressThe predict Cumbre patterns when Vieja associated it might has been with happen. the the growth most active of a detachment volcano in locationswells, surfers has not must been wait revealed months by at the a time group for of good surfers surfing who Although no historical records exist of lateral collapses of faultthe Canary under the Islands western for flank. most Ward of the and past Day125000 (2001)years, believe its firstconditions surfed the(www.northcore-europe.com/surf-videos.html wave in 2009 (Neil Britton, Richie Fitzgerald,). island volcanoes, around the world evidence exists of this thatpeak4.3 a liesLegends future2 km eruption above near sea the level summit and has is likely average to triggerslopes aof Mike Hamilton and Aaron Pierce), they describe the area as 1170 typeSee of Figs collapse 28 and in the 29for form images of scars of theon the wave seafloor. and the These sur-1220 flank15 − 20 failure° (Ward and and conclude Day, 2001). that the Day developing et al. (1999) detachment observe 1165 anrounding underwater area. mountain that focuses the wave as it emerges underlies most if not all of the western flank of the volcano. types of events could pose a threat of catastrophic propor-1215 thatIreland the has volcano a rich has literary undergone tradition, major and structuralas might be changes expected, in from 40-50 m open ocean into approximately 2-3 m depths. tions because of the landslide and the subsequent tsunami overthe ocean the past has several played thousand a central years place and in argue many that of this its ismyths due However, because this area is usually affected by crossing that such collapses would generate. In particular, sea floor toand stress legends. patterns Although associated there with are the clearly growth problems of a detachment in mak- swells, surfers must wait months at a time for good surfing mapping around the Hawaiian Islands in the Pacific Ocean faulting clear under scientific the western associations flank. Ward between and Day tales (2001) or legend believe and conditions (www.northcore-europe.com/surf-videos.html). and the Canary Islands in the Atlantic Ocean have revealed that a future eruption near the summit is likely to trigger a 2 1170 theseSee types Figs of 28 scars and29 and for landslide images deposits. of the wave Research and the carried sur-1220 flankRecurrent failure anddebates conclude take place that in the tsunami developing community detachment to dis- roundingout by Stephen area. Ward (UC Santa Cruz) and Simon Day (UC underliescuss the validity most ofif notsuch all high of speeds. the western flank of the volcano.

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awaycific wave“one fine classes, summer’s we include day” by a short a “terrible summary wave of fifty legendary feet [15waves.2 m] here high.” for The completeness. legend says that he cried out as he was taken “there will be coals coming to Triagh Praisce [“beside Ballinaskelligs4.3.1 The Creation Island”] of as the long Aran as I Islands live in Gleann Smoil”´ and that half burnt sods of turf were washed up at Balli- naskelligs for fourteen years after. It is said that Skellig and 1260 ValentiaThere is were a tradition separated of the from “bursting” the mainland of Galway after Bay this when event. the HaydenAran Islands(2012 were) describes joined howto Clare Domahnall by a sickle Ua shaped Murchadha penin- justifiessula. An how area “B ofothar´ flag na and Scairte” slate, like was that destroyed of Moher, by an may earth- have quakeonce extended and tsunami. towards Inisheer but was removed in early hu- man times (The Irish Times; 18/07/1956). Irish annals record Fig. 30. Simulation of potential tsunami created by collapse of La Fig. 30. Simulation of potential tsunami created by collapse of La1265 4.3.5an incident>1670: between Grafton 799 St. and 804 A.D.: (i) “Violent thun- Palma Island (snapshot of figure taken from Ward and Day (2001)). Palma Island, snapshot of Figure taken from Ward and Day (2001). der, accompanied by wind and fire, on the night before St. InPatrick’s a speech Day, given which in Georgian destroyed Dublin, many a persons, reference i.e. is made one thou- of asand girl who and ten was in drowned Corcu Baiscinn; “in a. . . wave and at the the sea foot divided of Grafton the is- specific wave classes, we include a short summary of leg- street” sometime after 1670 (The Irish Times, 21 Febru- endary waves here for completeness. land of Fita into three parts, and covered the land of Fita They suggest that a wedge shaped slide block with dimen-1270 arywith 1970). sand, that is as much land as would support 12 cows.” sions4.3.1 (15 The−20 Creationkm)×(15 of− the25 Arankm)× Islands(1−2) km may break off (U804.11); (ii) “There happened great wind, thunder, and and create a mega-tsunami that could propagate across the lightning, on the day before the festival of Patrick of this year, 1225 wholeThere Atlanticis a tradition basin. of the “bursting” of Galway Bay when the 5so Boulderthat one thousanddeposits and ten persons were killed in the ter- AranThey Islands model were the tsunamijoined to that Clare could by a be sickle generated shaped by penin- such ritory of Corca Bhaiscinn, and the sea divided the island of 3 asula.500 Ankm areaslide of block flag and travelling slate, like at a that maximum of Moher, speed may of have1001275 BoulderFitha into deposits three parts.” are of course(M799.11). not waves, but their presence m/sonce traveling extended60 towardskm out Inisheer to sea over but a was period removed of 10 minutes, in early provides impressive evidence for the impact of extreme wave fromhuman the times western (The flank Irish of Times Cumbre, 18 Vieja. July 1956). Run up Irish heights annals of events of some sort, and thus it is natural to include them in 4.3.2 The Buried City of Bannow 1230 therecord order an of incident hundreds between of meters 799 are and predicted 804 AD: around (i) “Violent neigh- a catalogue of extreme waves, especially in an Irish context. bouringthunder, Canary accompanied Islands by within windminutes and fire, of on the the slide. night before Waves It is well accepted that boulders can be transported and de- 50St.− Patrick’s100 m in Day, height which are predicted destroyed to many hit the persons, African i.e. main- one positedLegend by has the it ocean that the and island many ofexamples Bannow, can off be the found south across coast landthousand within and the ten first in hour, Corcu while Baiscinn;5−7 andm waves the sea are divided expected the theof Wexfordglobe. However, appeared the after way the in which “Buried this City occurs of Bannow” is a contro- had toisland reach of England Fita into and three Spain parts, within and covered3 − 6 hours. the land La of Palma Fita versialbeen engulfed matter. Most by a research wave in points olden to times either ( stormThe Irish waves Times or ; 1235 Islandwith sand, blocks that most is as of much the radiation land as would in this support northeasterly 12 cows” di-1280 tsunamis06/10/1951). as the source mechanism, though none of the re- rection.(U804.11 Along, 2012 the). (ii) coastlines “There happened of the Americas, great wind, waves thunder, up to search seems to consider rogue waves as a possibility. Bour- and lightning, on the day before the festival of Patrick of this geois (2009), Dominey-Howes (2007) and Paris et al. (2009) 25 m are estimated approximately 6 hours after the landslide 4.3.3 1014: The Battle of Clontarf occurs,year, so see that Fig. one 30. thousand and ten persons were killed in the give examples of boulder deposits documented all over the territoryNote that of Corcafor this Bhaiscinn, simulation, and the the slide sea volume divided of the500 islandkm3 world. The standard mechanism for determining the initia- tionLegend conditions has it that of boulder at “the Wartransport of the is Gaedhil given by withMassel the Gaill” and 1240 wasof Fitha a worst into case three estimate parts” ( ofM799.11 how much, 2012 material). could poten- tially break away from the volcano, but the block velocity of Doneone of(1993 Brian) and Boru’sNott grandsons,(1997, 2003 Turlough). The basis was of killed this con- when 4.3.2 The Buried City of Bannow 100 m/s was not a worst case estimate and when this velocity dition“the rushing relies on [...] calculating wave struck the inertia, a blow drag, against lift and the gravity weir of 1285 forcesCluaintairbh, acting on and the boulder so he was and determining drowned” ( whenThe Irish the clock- Times; isLegend increased has toit that150 them/s island the maximum of Bannow, wave off heights the south towards coast America double (Day, 2011).2 For Ireland, the risk would be wise10/01/1961). torque is greater than the anticlockwise torque, thus ini- of Wexford, appeared after the “Buried City of Bannow” had tiating the boulder to turn. 1245 around the South and West coasts and judging from Fig. 30, been engulfed by a wave in olden times (The Irish Times, In an Irish context, Hansom and Hall (2009) and Williams they would be of the same order as that of England (5−7 m). 4.4 Kerry Tsunami: ‘Bothar´ na Scairte’ 6 October 1951). (2010) report accumulations of large boulders on cliff tops Since these type of events occur very rarely, approximately up to 50 m high on the deep water coasts. They attribute the of4.3.3 the order 1014: of The thousands Battle of of Clontarf years, if Cumbre Vieja were to emplacementA folk tale of related these megaclasts in Domahnall to extreme Ua Murchadha’s storm waves; story in experience a major collapse it may not happen for a very long particular,‘Bothar´ naWilliams Scairte’( (Road2010) arguesof the Cataclysm) that there was (Hayden, no tsunami 2012) 1250 time.Legend However, has it that there at “The is presently War of the no Gaedhil way to withaccurately the Gaill” pre- 1290 actiontells of involved. the greatHall hurler et al. Clusach(2006)O’F´ identifyailbhe´ cliff-top who was storm swept dictone when of Brian it might Boru’s happen. grandsons, Turlough, was killed when “the rushing. . . wave struck a blow against the weir of Clu- depositsaway ‘one as ones fine summer’s that are typically day’ by located a ‘terrible on exposed wave fifty deep feet water[15.2 coastsm] high’. characterised The legend by says the presence that he cried of angular out as clasts he was 4.3aintairbh, Legends and so he was drowned” (The Irish Times, 10 Jan- uary 1961). >taken1 m in ‘there diameter will be asboulder coals coming spreads to or Triagh organised Praisce into [‘beside cliff- Ireland has a rich literary tradition, and as might be expected, topBallinaskelligs ridges. Cliff-top Island’] megaclast as long ridges as I live on the in Gleannwest coast Sm ofoil’´ Ire- and 1295 land demonstrate a pronounced imbrication on the seaward the4.3.4 ocean Kerry has tsunami:played a central“Bothar´ place na Scairte” in many of its myths that half burnt sods of turf were washed up at Ballinaskelligs marginsfor fourteen of the years ridges. after.Williams It is( said2010 that) attributes Skellig this and organ- Valen- 1255 and legends. Although there are clearly problems in making A folk tale related in Domahnall Ua Murchadha’s story isation of boulders to the repetitive impact of large storm clear scientific associations between tales or legend and spe- tia were separated from the mainland after this event. Hay- “Bothar´ na Scairte” (Road of the Cataclysm) (Hayden, 2012) wavesden (2012) and suggests describes that how storm Domahnall waves areUa Murchadha unlikely to justifiestrans- ´ tells2Recurrent of the great debates hurler take Clusach place in theO’F tsunamiailbhe,´ community who was swept to dis- porthow such ‘Bothar´ clasts na more Scairte’ than was a few destroyed tens of bymeters an earthquake inland. Hall and cuss the validity of such high speeds. 1300 tsunami. Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 www.nat-hazards-earth-syst-sci.net/13/625/2013/ L. O’Brien et al.: Extreme wave events in Ireland 645 et al. (2006) characterise the waves that generate cliff-top 6 Conclusions boulder accumulations as ones that come from deep water offshore with full exposure to the storm and have limited on- The survey provided in this paper has attempted to cover the shore attenuation. Williams and Hall (2004) also point out most well-known (or at least the most accessible) reports of that the waves impacting the cliff top where deposits are extreme wave events in Ireland over the last 15 000 yr, but found in western Ireland have not been enhanced by con- this list cannot, of course, be considered exhaustive. In fact, striction in bays and suggest that amplification of waves due since this is the first such survey of its nature (to our knowl- to constructive interference of incoming waves with waves edge), it may well be that we have missed a number of im- reflected from the cliffs may need to be considered. These portant events that have occurred in the past. This may be effects have been demonstrated by Hu et al. (2000). especially the case when records have been made and kept Despite the proven existence of extreme waves in the locally. One of the main objectives of this paper therefore is ocean greater than 35 m, none have been described as > to stimulate others to search and add to the list of extreme 50 m, so an alternative mechanism of movement must be in- events reported here. In this way, Ireland will establish an volved for the case of Ireland. Overtopping waves can be ac- accurate database of its past ocean environment, which will celerated in a landward direction by high landward wind ve- be increasingly necessary in order to accurately inform the locities. Kharif et al. (2008) showed that extreme wave events future development of this precious natural resource. may be sustained longer by the air flow separation occurring Our work leads us to draw a number of conclusions that on the leeward side of the crests. However, it has also been will be important to in mind for future work in under- suggested that overtopping of waves on cliffs results in the standing the occurrence and risks of extreme wave events in formation of a landward moving high velocity bore which Ireland. One initial point that is immediately apparent are the transports megaclasts (some tens of tonnes) across cliff-top problems raised by the imprecise way in which wave events platforms (Williams, 2010). Cox and Ortega (2002) demon- are understood and described by non-scientists. For exam- strated the downward collapse of overtopping waves onto a ple, the expression “tidal wave” has been used inaccurately suspended platform experimentally and showed that the wa- in the past to describe all kinds of flooding, due not only to ter column above the platform is transformed into a landward tsunamis but also due to storm surges. The tsunami risk for propagating turbulent bore with a velocity up to 2.4 times Ireland is of course very low, however, and we have con- that of the initial wave velocity. Since turbulent bores may cluded that the flooding often described as “tidal waves” has be likened to tsunamis in terms of their method of propaga- really been due to other mechanisms such as storm surges. tion, Williams (2010) believes it is this process that could On the other hand, concerning unpredictable and destruc- explain the movement of boulders at such extreme heights tive rogue waves, the relatively recent access to wave data above sea level. Furthermore, Hu et al. (2000) carried out in Ireland shows that the probability of occurrence of rogue numerical simulations of a wave surge crossing an underwa- waves is larger than expected, especially on the west coast ter step, showing that the step increased the forward velocity of Ireland. It is indeed quite extraordinary that with only a of the surge by up to 40 % (Williams and Hall, 2004). Hall handful of wave buoys over a few years one has been able et al. (2006) propose that platforms and ramps on cliff tops to record the occurrence of rogue waves (those satisfying are swept by wave-derived bores of water, parts of which quantitative criteria), because rogue waves are by definition can move up to 14 m s−1 (avg. 7 m s−1) while transporting localized in space and the number of buoy sampling points boulders of up to 40 m3. Since megaclast ridges at 50 m on are few. This points to further directions of study examining the north coast of Ireland are separated from the sea by a whether Irish wind patterns and/or factors such as currents number of platforms, Williams and Hall (2004) believe that and bathymetry may be favouring rogue wave formation off these may have accelerated incoming waves sufficiently to the Irish coast. emplace clasts at this height. Concerning long term trends in the nature of waves around Although there are those who believe that tsunamis are the Ireland, at this stage and based on our data, it is not possible most probable explanation of boulder ridges in these areas to conclude whether the number of extreme wave events in (Kelletat, 2008; Scheffers et al., 2009, 2010), a new study Ireland is increasing or decreasing. As discussed earlier, the by Cox et al. (2012) concludes that boulders ridges on the data we used to establish this catalogue is sometimes from Aran Islands have been caused by storm waves. They jus- untrained observers, and thus it is dangerous to draw firm tify this through radiocarbon dating of shells indicating post- conclusions. Yet it is clear that the west coast is more vulner- 1950 emplacement, eyewitness accounts of boulders appear- able, and this already identifies a geographical area where ing after a storm on 5 January 1991, repeated photography of future research efforts can be concentrated. However, this the area and comparison with Ordnance Survey maps from highlights how it is important to educate the public to de- 1839. This evidence points to recent boulder movement ac- scribe accurately what they observe. Of course it is difficult tivity, and due to the lack of significant tsunami evidence in to give quantitative measurements when one observes an ex- the North Atlantic since the 1755 Lisbon event, they believe treme event, but a few important characteristics such as short that storm waves are the only plausible cause. vs long and widespread vs localized are essential to know. www.nat-hazards-earth-syst-sci.net/13/625/2013/ Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 646 L. O’Brien et al.: Extreme wave events in Ireland

Engaging the public in the observation of the behaviour of kindly acknowledged. The authors would also like to thank Owen the marine environment will also bring many other benefits Sinnott for providing information about the Kilmore events, of course, increasing awareness of its vital planetary impor- Michael Williams for helping with some of the references and tance. Brendan Cahill for providing the data shown in Fig. 25. Last but At the same time of course, developments in quantitative not least, the authors are grateful to the significant contribution of measuring devices such as buoys are to be encouraged and the referees to the improvement of the paper. increased. It is only with accurate physical measurement that Edited by: S. Tinti a more complete picture will emerge of the nature and fre- Reviewed by: two anonymous referees quency of wave events around Ireland. It is important to re- call in this context how, despite centuries of anecdotal ev- idence, it was only after the quantitative wave record of the References Draupner New Year’s Wave was measured in 1995 that rogue waves were accepted as a genuinely separate class of waves Ambraseys, N. and Synolakis, C. E.: Tsunami Catalogs for the meriting detailed study. Eastern Mediterranean, Revisited, J. Earthq. Eng., 14, 309–330, We also wish to stress the great potential of new devel- 2010. Berninghausen, W. H.: Tsunamis and Seismic Seiches reported opments in land-based observation of wave data. Specifi- from the Western North and South Atlantic and the Coastal Wa- cally, ocean waves generate pressure changes at the sea bed ters of Northwestern Europe, Informal report, Naval Oceano- which generate continuous background seismic noise or mi- graphic Office Washington, D.C. 20390, 1968. croseisms. These are associated with ocean wave activity Borlase, W.: On the Extraordinary Agitation of the Waters in and are generally stronger in coastal areas, although they Mounts Bay, and Other Places, 31 March, 1761, The Royal Soci- are recorded on terrestrial seismic stations throughout the ety of London, Philosophical Transactions, reproduced in Read- world. Background seismic noise levels increase during pe- ings in Natural Philosophy, compiled by: Rev. C.C. Clarke, 2nd riods of increased ocean wave activity and, since Ireland is Edn., London, 397–399, 1830. now equipped with an extensive seismic network, this rep- Bourgeois, J.: The Sea: Tsunamis, Vol. 15, Chap. 3: Geological Ef- resents an exciting opportunity to deploy a new set of in- fects and Records of Tsunamis, 53–91, Harvard University Press, struments for understanding ocean wave phenomena (Moni 2009. Bryn, P., Berg, K., Forsberg, C. F., Solheim, A., and Kvalstad, T. J.: et al., 2012). Explaining the Storegga Slide, Mar. Petrol. Geol., 22, 11–19, 2005. Bugge, T., Belderson, R. H., and Kenyon, N. H.: The Storegga Slide, Appendix A Phil. Trans. R. Soc. Lond. A, 325, 357–388, 1988. Bunbury, T.: The Night of the Big Wind 6th-7th January 1839, web- Earthquake magnitude site, www.turtlebunbury.com/history/history irish/history irish bigwind.htm (last access: February 2012), historian, 2005. – Modified Mercalli Intensity Scale of 1931 (NOAA) Chabchoub, A., Hoffmann, N. P., and Akhmediev, N.: Rogue Wave Observation in a Water Wave Tank, Phys. Rev. Lett., 106, 2, 6 pp., – 9: Damage considerable in specially designed doi:10.1103/PhysRevLett.106.204502, 2011. structures; well-designed frame structures thrown Chabchoub, A., Hoffmann, N. P., Onorato, M., and Akhme- out of plumb; great in substantial buildings, with diev, N.: Super rogue waves: Observation of a higher- partial collapse. Buildings shifted off foundations. order breather in water waves, Phys. Rev. X, 2, 6 pp., Ground cracked conspicuously. Underground pipes doi:10.1103/PhysRevX.2.011015, 2012. broken. CIL: Commissioners of Irish Lights, website, www. commissionersofirishlights.com/cil/aids-to-navigation/ – 11: Few, if any (masonry), structures remain stand- lighthouses.aspx, last access: February, 2012. ing. Bridges destroyed. Broad fissures in ground. cork-guide.ie: Cork-Guide, website, www.cork-guide.ie/ Underground pipelines completely out of service. barleycove/index.html (last access: February 2012), 2012. Earth slumps and land slips in soft ground. Rails Costeloe, M.: Calf Rock, Tech. rep., Commisioners of Irish Lights, bent greatly. provided by: Robert Sparkes of the Commissioners of Irish Lights, 2000. Cox, R., Zentner, D. B., Kirchner, B. J., and Cook, M. S.: Boulder Ridges on the Aran Islands (Ireland): Revent movements casued Acknowledgements. This work was funded by IRCSET under by storm waves, not tsunamis, The Journal of Geology, 120, 249– the Postgraduate Research Scholarship Scheme, ERC under the 272, 2012. research project ERC-2011-AdG 290562-MULTIWAVE and Cox, T. D. and Ortega, J. A.: Laboratory observations of green water SFI under the programme ERC Starter Grant – Top Up, Grant overtopping on a fixed deck, Ocean Eng., 29, 1827–1840, 2002. 12/ERC/E2227. Fruitful discussions with the Marine Institute, Dawson, A., Musson, R., Foster, I., and Brunsden, D.: Abnormal Lieutenant Commander Terry Ward from the Irish Naval Service historic sea-surface fluctuations, SW England, Mar. Geol., 170, and Robert Sparks from the Commissioners of Irish Lights are 59–68, 2000.

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Day, S.: Testing tsunami models with historical and instrumental 200, 166–183, Sediment. Geol., 211, 87–91, 2008. records of recent tsunamis, Presentation at UCL workshop Au- Kharif, C. and Pelinovsky, E.: Physical mechanisms of the rogue gust 2011, 2011. wave phenomenon, Eur. J. Mech. B-Fluids, 22, 603–634, 2003. Day, S., Carracedo, J., Guillou, H., and Gravestock, P.: Recent struc- Kharif, C., Giovanangeli, J.-P., Touboul, J., Grare, L., and Peli- tural evolution of the Cumbre Vieja volcano, La Palma, Canary novsky, E.: Influence of wind on extreme wave events: experi- Islands: volcanic rift zone reconfiguration as a precursor to vol- mental and numerical approaches, J. Fluid Mech., 594, 209–247, cano flank instability?, J. Volcanol. Geotherm. Res., 94, 135– doi:10.1017/S0022112007009019, 2008. 167, 1999. Kibler, B., Fatome, J., Finot, C., Millot, G., Dias, F., Genty, G., Delaney, G. M.: The Night of the Big Wind in Co. Mayo, Mayo Akhmediev, N., and Dudley, J. M.: The Peregrine in non- Alive Magazine, website, www.mayoalive.com/MagApr23/ linear fibre optics, Nat. Phys., 6, 790–795, 2010. BigWind.htm (last access: February 2012), 1996. Kibler, B., Fatome, J., Finot, C., Millot, G., Genty, G., Wetzel, DIAS: Dublin Institute for Advanced Studies Seismic Network, B., Akhmediev, N., Dias, F., and Dudley, J. M.: Observation of website, www.dias.ie/irish seismicity/, last access: 2012. Kuznetsov-Ma soliton dynamics in optical fibre, Scientific Re- Dominey-Howes, D.: Geological and historical records of tsunmai ports, 2, 463, doi:10.1038/srep00463, 2012. in Australia, Mar. Geol., 239, 99–123, 2007. Larkin, J.: Innishannon’s Tsunami, Innishannon Candlelight (Can- Eagle, J.: Irish Lighthouses by John Eagle, website, indigo.ie/ dlelight), 2010. ∼eaglejr/, last access: February, 2012. Levin, B. and Nosov, M.: Physics of Tsunamis, chap. 4: The ECMWF: European Centre for Medium-Range Weather Forecasts, Physics of Tsunami Formation by Sources of Nonseismic Ori- Weather Forecasting Model, www.ecmwf.int/ (last access: June gin, Springer, 2009. 2012), 2012. Lyons, M. J.: Tidal Wave at Westport Quay, from notes made by the Forsythe, W., Breen, C., Callaghan, C., and McConkey, R.: Historic late Michael J. Lyons about his early experiences in Westport, storms and shipwrecks in Ireland: a preliminary survey of severe Cathair na Mart- Journal of Westport Historical Society, 13, 135– synoptic conditions as a causal factor in underwater archaeology, 136, 1993. Int. J. Naut. Archaeol., 29, 247–259, 2000. M799.11: Annal of the Four Masters, CELT: The Corpus of Elec- galwaytourism.ie: www.galwaytourism.ie/ tronic Texts (via UCC), www.ucc.ie/celt/published/T100005A/ pgalway-city-landmarks.html (last access: February 2012), index.html, last access: February, 2012. 2012. Massel, S. and Done, T.: Effects of cyclone waves on massive coral Hall, A., Hansom, J., Williams, D., and Jarvis, J.: Distribution, geo- assemblages on the Great Barrier Reef: meteorology, hydrody- morphology and lithofacies of cliff-top storm deposits: Examples namics and demography, Coral Reefs, 12, 153–166, 1993. from the high-energy coasts of Scotland and Ireland, Mar. Geol., Mecking, J. V., Fogarty, C. T., Greatbatch, R. J., Sheng, J., and Mer- 232, 131–155, 2006. cer, D.: Using atmospheric model output to simulate the meteo- Hansom, J. and Hall, A.: Magnitude and frequency of extra-tropical rological tsunami response to Tropical Storm Helene (2000), J. North Atlantic cyclones: A chronology from cliff-top storm de- Geophys. Res., 114, doi:10.1029/2009JC005290, 2009. posits, Quaternary Int., 195, 42–52, 2009. Met.ie: Met Eireann,´ website, www.met.ie, last access: February, Harrington, G.: The Harringtons and Calf Rock, Beam: 2012. The Journal of the Irish Lighthouse Service, 29, Met.ie-Fastnet: Exceptional weather events, Storm – The www.commissionersofirishlights.com/cil/publications/ Fastnet Disaster August 1979, Met Eireann,´ www.met.ie/ beam-magazines/volume-29/the-harringtons-and-calf-rock. climate-ireland/weather-events/Aug1979 Storm.PDF, unknown. aspx, 2000–2001. Met.ie/wind: Climate-Wind-Notable Storms, website, www.met.ie/ Haslett, S. K. and Bryant, E. A.: Meteorological tsunamis in South- climate/wind.asp, last access: 2012. ern Britain: an historical review, Geolog. Rev., 99, 146–163, Metoffice.gov.uk: The Beaufort Scale, webpage, www.metoffice. 2009. gov.uk/media/pdf/4/4/Fact Sheet No. 6 - Beaufort Scale.pdf, Haslett, S. K., Mellor, H. E., and Bryant, E. A.: Meteo-tsunami haz- last access: March, 2012. ard associated with summer thunderstorms in the United King- Moni, A., Donne, S., Bean, C., Craig, D., Mollhoff,¨ M., Hauser, F., dom, Phys. Chem. Earth, Parts A/B/C, 34, 1016–1022, 2009. Braiden, A., Lambkin, K., Creamer, C., and White, M.: Towards Hayden, A.: Clusach O’Failbhe,´ ‘Bothar´ ne Scairte’ and Church Is- ocean wave energy-potential quantification from a terrestrially- land: Evidence of a Kerry Tsunami?, To appear in: Kerry Ar- based seismic observation system, in: Proceedings of the Fourth chaelogical and Historical Society, 2012, 2012. International Conference on Ocean Energy, 2012. Holmes, R., Long, D., and Dodd, L. R.: Large-scale debrites and Murphy, C. R., Finn, C. N. P., Krause, L.-C. W., Wamback, C. A., submarine landslides on the Barra Fan, west of Britain, Geolog- and Cooper, C. P. O. F. C. R.: HMCS CHICOUTIMI Fires and ical Society, London, Special Publications, 129, 67–79, 1998. Casualties Board of Inquiry Final Report, Tech. Rep., National Hu, K., Mingham, C., and Causon, D.: Numerical simulation of Defence and the Canadian Forces, www.forces.gc.ca/site/focus/ wave overtopping of coastal structures using the non-linear shal- chicoutimi/es-resume-eng.asp, 2004. low water equations, Coastal Eng., 41, 433–465, 2000. Nicola, L.: A letter to James Simon, Esq, F. R. S. 7th of December Huvenne, V. A. I., Croker, P. F., and Henriet, J.-P.: A refreshing 1755, Kinsale, Phil. Transa. (1683–1775), 49, 351–398, 1755– 3D view of an ancient sediment collapse and slope failure, Terra 1756. Nova, 14, 33–40, 2002. Nikolkina, I. and Didenkulova, I.: Rogue waves in 2006–2010, Nat. Kelletat, D.: Comments to Dawson, A.G. and Stewart, I. (2007), Hazards Earth Syst. Sci., 11, 2913–2924, doi:10.5194/nhess-11- Tsunami deposits in the geological record.-Sedimentary Geology 2913-2011, 2011.

www.nat-hazards-earth-syst-sci.net/13/625/2013/ Nat. Hazards Earth Syst. Sci., 13, 625–648, 2013 648 L. O’Brien et al.: Extreme wave events in Ireland

NOAA: NOAA/WDC Tsunami Event Database, National Oceanic Shields, L. and Fitzgerald, D.: The “Night of the Big Wind” and Atmospheric Administration Website, www.ngdc.noaa.gov/ in Ireland, 6–7 January 1839, Irish Geography, 22, available nndc/struts/form?t=101650\&s=70\&d=7, last access: Febru- at: www.met.ie/climate-ireland/weather-events/Jan1839 Storm. ary, 2012. PDF, 1989. Nott, J.: Extremely high-energy wave deposits inside the Great Bar- Stefanakis, T. S., Dias, F., and Dutykh, D.: Local Run-Up Ampli- rier Reef, Australia: determining the cause- tsunami or tropical fication by Resonant Wave Interactions, Phys. Rev. Lett., 107, cyclone, Mar. Geol., 141, 193–207, 1997. 124502, doi:10.1103/PhysRevLett.107.124502, 2011. Nott, J.: Tsunami or Storm Waves? – Determining the Origin of a Stromeyer, C. E.: Abnormal Atlantic Waves, Nature, 51, 437–438, Spectacular Field of Wave Emplaced Boulders Using Numeri- 1895. cal Storm Surge and Wave Models and Hydrodynamic Transport Synolakis, C. E. and Bernard, E. N.: Tsunami science before and Equations, J. Coast. Res., 19, 348–356, 2003. beyond Boxing Day 2004, Phil. Trans. R. Soc. A, 364, 2231– Okal, E. A. and Synolakis, C. E.: A Theoretical Comparison of 2265, 2006. Tsunamis from Dislocations and Landslides, Pure Appl. Geo- Tamura, H., Waseda, T., and Miyazawa, Y.: Freakish sea phys., 160, 2177–2188, 2003. state and swell-windsea coupling: Numerical study of the Owen, M., Day, S., Long, D., and Maslin, M.: Investigations on Suwa-Maru incident, Geophys. Res. Lett., 36, L01607, the Peach 4 Debrite, a Late Pleistocene Mass Movement on doi:10.1029/2008GL036280, 2009. the Northwest British , in: Submarine Mass Tinti, S., Maramai, A., and Graziani, L.: The new catalogue of the Movements and Their Consequences, Series on Advances in Nat- Italian tsunamis, Nat. Hazards, 33, 439–465, 2004. ural and Technological Hazards Research by Springer, Austin, U804.11: The Annals of , CELT: The Corpus of Electronic Texas, USA, 2010. Texts (via UCC), www.ucc.ie/celt/online/T100001A/, last ac- Paris, R., Wassmer, P., Sartohadi, J., Lavigne, F., Barthomeuf, B., cess: February, 2012. Desgages, E., Grancher, D., Baumert, P., Vautier, F., Brunstein, Ward, S. N. and Day, S.: Cumbre Vieja Volcano – Potential collapse D., and Gomez, C.: Tsunamis as geomorphic crises: Lessons and tsunami at La Palma, Canary Islands, Geophys. Res. Lett., from the December 26, 2004 tsunami in Lhok Nga, West Banda 28, 3397, doi:10.1029/2001GL013110, 2001. Aceh (Sumatra, Indonesia), Geomorphology, 104, 59–72, 2009. Williams, D. M.: Mechanisms of wave transport of megaclasts on Peregrine, D. H.: Water Waves, Nonlinear Schrodinger¨ Equations elevated cliff-top platforms: examples from western Ireland rele- and Their Solutions, J. Aust. Math. Soc. B, 25, 16–43, 1983. vant to the storm-wave versus tsunami controversy, Irish J. Earth Rabinovich, A. B., Vilibic, I., and Tinti, S.: Meteorological Sci., 28, 13–23, 2010. tsunamis: Atmospherically induced destructive ocean waves in Williams, D. M. and Hall, A. M.: Cliff-top megaclast deposits of the tsunami frequency band, Phys. Chem. Earth, 34, 891–893, Ireland, a record of extreme waves in the North Atlantic-storms 2009. or tsunamis?, Mar. Geol., 206, 101–117, 2004. RAF: Royal Air Force, website, available at: www.raf.mod. uk/news/archive/ambassador-thanks-crew-28112011 (last ac- Newspaper references cess: February 2012), 2011. RAS: The Historical Tsunami Database for the World Ocean, web- BBC News: www.bbc.com/news page, Institute of Computational and Mathemat- BBC Sport: www.bbc.co.uk/sport/0/ ical Geophysics Siberian Division Russian Academy of Sci- Coleraine Times: www.colerainetimes.co.uk/ ences (RAS), Tsunami Labratory, Novosibirsk, Russia, available at: tsun.sscc.ru/nh/tsunami.php, last access: February, 2012. Los Angeles Times: www.latimes.com/ Ryan, P.: Eagle Island East storm December 29th 1894, Letter RTE News: www.rte.ie/news archive, provided by: Robert Sparkes of the Commissioners of The Belfast Telegraph: www.belfasttelegraph.co.uk/ Irish Lights, 1895. The Economist: www.economist.com Scanlan, B.: In Retrospect, Beam: The Journal of the Irish Light- The Galway Vindicator: Archives National Library of house Service, 25, available at: www.commissionersofirishlights. Ireland com/cil/publications/beam-magazines/volume-25/in-retrospect. The Galway Weekly Advertiser: Archives National Library of aspx (last access: February 2012), 1993. Ireland Scheffers, A., Scheffers, S., Kelletat, D., and Browne, T.: Wave- The Guardian: www.guardian.co.uk/ Emplaced Coarse Debris and Megaclasts in Ireland and Scot- land: Boulder Transport in a High-Energy Littoral Environment, The Irish Independent: Archives (www.irishnewsarchive.com) and J. Geol., 117, 553–573, 2009. www.independent.ie Scheffers, A., Kelletat, D., Haslett, S., Scheffers, S., and Browne, The Irish Times: The Irish Times digital archives and www. T.: Coastal boulder deposits in Galway Bay and the Aran Islands, irishtimes.com western Ireland, Z. Geomorphologie, 54, 247–279, 2010. The Nation: Archives (www.irishnewsarchive.com)

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