Reminiscences of the Great Tsunami of July 1627 in the Frentana Coast
Total Page:16
File Type:pdf, Size:1020Kb
Mem. Descr. Carta Geol. d’It. XCVi (2014), pp. 349-356, figg. 7 Reminiscences of the great tsunami of July 1627 in the Frentana coast: the case of Lanciano-San Vito Chietino port Reminiscenze del grande tsunami del luglio 1627 sulla costa Frentana: il caso di Lanciano e il porto di San Vito Chietino StoppA f. (*) AbStrACt - Chronicles and legends related to the telluric riASSUnto - Cronache e leggende legate a sommovimenti upheavals frentana dot the coast in the province of Chieti. tellurici costellano la Costa frentana in provincia di Chieti. these myths fable describing the mountains and cities that tali miti favolistici descrivono monti e città che si inabissano plunge into the sea, migration, persistent fear of the sea and nel mare, migrazioni, una persistente paura del mare e atti di acts of faith of the people who invoke the protection of sea fede popolare che invocano la protezione di divinità marine gods and telluric. While many of these legends are probably e telluriche. Mentre molte di queste leggende sono probabil- exaggerated and magnified, objective, however, is the scope mente esagerate ed ingigantite, oggettiva è invece la portata of historical changes that have occurred. in fact, in the hi- di mutamenti storici avvenuti. infatti, nel contesto storico storical context in which these legends have formed a corpus durante il quale queste leggende hanno formato un corpus of oral tradition, we are witnessing a drastic change of use di tradizione orale, si assiste a un drastico cambio di destina- of land and habits related to a change in the pattern of socio- zione d’uso del territorio e di abitudini legate a una mutata economic. these changes are supported by direct and indi- configurazione socio-economica. tali mutamenti trovano rect in the quantification of the costs of repair, in the deeds conferme dirette ed indirette nelle quantificazioni dei costi of sale and in the records of the variations of trade and the di riparazione, negli atti di compravendita e nelle registrazioni movement of the community. on the basis of historical re- delle variazioni dei traffici commerciali e degli spostamenti ferences and mythopoeic interpretation, these phenomena di comunità. Sulla base dei riferimenti storici e della inter- may be associated with the overall effects of the earthquake pretazione mitopoietica, tali fenomeni possono essere nel and, above all, the tsunami of 1627. thereafter, it introduces complesso associati agli effetti del terremoto e, soprattutto, new coastal economic systems more “terrestrial” and the old dello tsunami del 1627. dopo tale data, vengono introdotti fabric and commercial political will contract for nearly a cen- nuovi sistemi economici costieri più “terricoli” e il vecchio Atti dellA ConferenzA nAzionAle 6, 7, 8 ottobre 2010 ottobre 8 7, 6, nAzionAle ConferenzA dellA Atti tury, dismembered and redistributed. A substantial undere- tessuto commerciale e politico viene contratto per quasi un stimation of the possible effects of the earthquake and secolo, smembrato e ridistribuito. Una sostanziale possibile tsunami comes from two factors. the first is that historians sottostima degli effetti di tale terremoto e tsunami deriva da generally have a low sensitivity to the influence of the phy- due fattori. il primo è che gli storici hanno in genere una sical phenomena on human society and, second, that the am- scarsa sensibilità per l’influenza del fenomeni fisici sulla so- plitude of the geological phenomenon is still uncertain. cietà umana e, il secondo, che l’ampiezza del fenomeno geo- However, the effect documented by cultural anthropological logico è ancora incerta. tuttavia, l’effetto culturale documen- study leads to a reconsideration of the immediate risk of a tato dallo studio antropologico induce a una immediata ri- tsunami on the Abruzzo coast, especially in light of an irra- considerazione del rischio tsunami sulle coste abruzzesi, tional structure of bathing facilities and recreational facilities anche alla luce di una irrazionale strutturazione degli impianti associated with a disorder and vulnerability of escape routes balneari e delle installazioni da diporto associate a un disor- and emergency. dine e vulnerabilità delle vie di fuga e di soccorso. Key WordS: Abruzzi region, Anthropology, Geomithology, pArole CHiAVe: Abruzzo, Antropologia, geomitologia, 1627 Adriatic tsunami, feast of our lady of thee Sea tsunami adriatico del 1627, festa di nostra Signora del Mare (*) Centro di Antropologia territoriale degli Abruzzi, Science department, UdA - [email protected] 350 f. StoppA 1 - introdUCtion and increases sensibly the risk also in terms of exposed artifacts and human beings (StoppA, 2010a). poor sus- the Abruzzi mainland region is all classified for the tainable governance of the territory multiplies different seismic hazard even if the real hazard may be underes- hazards increasing vulnerability and the amount of ar- timated as demonstrated by the occurrence and conse- tifacts, goods and human beings in the hazardous area. quence of l’Aquila earthquake on 6 April 2009. the Moderate tsunamis have occurred frequently along seismic hazard of the coastal area is practically uneval- the coast. the effect of the ingression of a iV-V in- uated due to the fact that seismogenetic structures, pos- tensity tsunami (0.5-1m high) is certainly less spectac- sibly identified by seismic profiles and weak seismicity, ular and destructive than a high wave (2-4 m high) do not break out at the surface ad remain buried all the impacting on the beach and moving inland for kilome- time in this area. Historical off-shore seismicity is ters in flat areas, but is still able to trigger strong cur- largely unknown and based on a few event occurred in rents interfering with the coastal morphology and any the last century (boSCHi et alii, 1997). oldest observa- existing structures (ports, piers, breakwaters, etc). these tions, possible related to tsunamigenic events, are con- kind of tsunami is likely to produce freighting and con- fuse and solely reported by chronicles of the localized siderable panic in the exposed population which would effects on mainland and isolated buildings such as cas- run to higher ground. boats are expected to move tles, monasteries (e.g. MAMMArellA, 1990). in addition, strongly onshore, crash into each other, shatter on the storm surges, floods, coastal landslides and tsunami rocks or overturn. flooding of outdoor facilities, such probably overlap in the old chronicles and legends. less as beach resorts and of near-shore road, railroad and than 50% of the events that are recorded on the west- low-ground residential areas is expected, even if most ern coast of the were earthquake-triggered tsunamis, masonry buildings withstand. this moderate hazard while the others are sea effects attributed to meteoro- scenario in fact implies a very high risk if a tsunami logical forcing and submarine landslides (tinti et alii, would hit the coast and ports during the summer pe- 2004; VilibiC & SepiC, 2009; zeCCHi, 2006). transfor- riod by day when beach are over-crowed and ports mations of the human settlements along the coast were hosts many small leisure boats. in addition, tsunami often related to these phenomena but the exact nature hazard could be underestimated as a consequence of of these events is doubtful. seismic hazard underestimation. pure probabilistic there are several citations in the traditional litera- methods may be much too optimistic. ture corpus of a destructive earthquake occurred on 1088 in Southern Abruzzi, badly damaging the dioclet- ian bridge in lanciano, the San Giovanni in Venere 2. - tSUnAMi in tHe AdriAtiC SeA Abbey in frentania e a tsunami which flooded the San- gro-river coast ruining the Santo Stefano in Rivo Maris only a few seismic stations are located in and abbey (e.g. MAMArellA, 1990). this event is not re- mostly inside the mountain chain. GpS measurements ported or credited in the official italian tsunami and are performed only on mainland and the off-shore seis- earthquake catalogs but needs more work to be elimi- mic data set is too scarce to allow a serious Gutenberg- nated or confirmed. richter evaluation. However, basing on regional Civita di Sangro, near the estuary of the Sangro seismicity and general geology of the Adriatic foredeep, river, and rocca di osento, near the estuary of the os- it is clear that has seismogenic sources that can easily ento river, suffered serious damage at the end of the release energies close to magnitude (Mw) ~5.5,(ViSini Xiii century, and the King Carlo the ist had to author- et alii, 2010). Although these magnitudes cannot generate ize the movement of the two villages to a safer place very large tsunamis, i.e. >Vi intensity in the papadopou- (priori, 1957, AqUilAno, 1997). in general, only land- los imamura scale, smaller tsunamis, 0,5-1 meter high, slides and earthquakes produce the abandon of a city. of intensity <V seem frequent and would impact on the river flooding is unlikely as old settlements were up to vulnerable coastal system which is not specifically the main flooding level and only unpredictable large warned and/or alerted and provided with preventive sys- events may damage them. the first place was located tems (tiberti et alii, 2008). tsunamis related to medium in the valley and possibly flooded by a tsunami wave M earthquakes (5.5-6) are potentially triggered by con- moving up stream, the second place on a low marine sequent underwater landslides. landslides may occur also terrace near the sea could be hit by a large tsunami or in absence of a noticeable seismic disturbance and are collapsed in a landslide. Seismic catalogues do not show mainly related to turbidity currents descending in the any suitable event in the area but major earthquakes are tremiti trench slope and to local collapse of the recorded on the Serbia-Montenegro coast on 1280 an holocene, muddy pro-delta accumulated along the 1300 (Albini, 2004).