DOCSLIB.ORG

A Detection of Milankovitch Frequencies in Global Volcanic Activity

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Detection of Milankovitch Frequencies in Global Volcanic Activity A detection of Milankovitch frequencies in global volcanic activity Steffen Kutterolf1*, Marion Jegen1, Jerry X. Mitrovica2, Tom Kwasnitschka1, Armin Freundt1, and Peter J. Huybers2 1Collaborative Research Center (SFB) 574, GEOMAR, Wischhofstrasse 1-3, 24148 Kiel, Germany 2Department of Earth & Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA ABSTRACT 490 k.y. in the Central American Volcanic Arc A rigorous detection of Milankovitch periodicities in volcanic output across the Pleistocene- (CAVA; Fig. 1). We augment these data with Holocene ice age has remained elusive. We report on a spectral analysis of a large number of 42 tephra layers extending over ~1 m.y. found well-preserved ash plume deposits recorded in marine sediments along the Pacifi c Ring of in Deep Sea Drilling Project (DSDP) and Fire. Our analysis yields a statistically signifi cant detection of a spectral peak at the obliquity Ocean Drilling Program (ODP) Legs offshore period. We propose that this variability in volcanic activity results from crustal stress changes of Central America. The marine tephra records associated with ice age mass redistribution. In particular, increased volcanism lags behind in Central America are dated using estimated the highest rate of increasing eustatic sea level (decreasing global ice volume) by 4.0 ± 3.6 k.y. sedimentation rates and/or through correlation and correlates with numerical predictions of stress changes at volcanically active sites. These with radiometrically dated on-land deposits results support the presence of a causal link between variations in ice age climate, continental (e.g., Kutterolf et al., 2008; also see the GSA stress fi eld, and volcanism. Data Repository1). The second data subset includes DSDP, INTRODUCTION Our data set is comprised of two subsets. The ODP, and IODP (Integrated Ocean Drill- Volcanic activity varies over a wide range of fi rst involves records from Central America and ing Program) drill core records from other temporal scales, from cycles with less than one- consists, in part, of 49 eruptions preserved in sites along the ROF (Fig. 1; Table DR1 in the year periods in single volcanic systems, to inter- tephra layers from 56 cross-correlated gravity Data Repository). The records extend back vals extending out to plate tectonic time scales cores. These data provide an almost complete to ca. 1 Ma, but rarely include the shallowest (Cambray and Cadet, 1994; Kennett et al., 1977; record of large explosive eruptions (VEI >5 sediments with ages up to ca. 100 ka, and have Mason et al., 2004; Paterne et al., 1990). Con- [Volcanic Explosivity Index]) over the past thus been complemented by data from gravity nections between volcanism, the global carbon cycle and climate appear to be well established at the longest of these time scales (Walker et al., 1981). Moreover, on seasonal-to-decadal time Aleutian Basin Bering scales, volcanic eruptions are known to infl u- Sea of Sea ence climate (e.g., Hansen et al., 1992; Robock, Asia Okhotsk Gulf of North Alaska 2000), and perhaps vice versa (Novell et al., Alaska America 2006; Rampino et al., 1979). We focus on the Kamchatka Aleutian Arc intermediate time scales (103–105 yr) relevant to Sea of Japan Westerly variations during the ice age. There is evidence stratospheric winds that subaerial volcanism increased signifi cantly during the last deglaciation phase of the ice age (Huybers and Langmuir, 2009; Jull and 15°N Nankai Mc Kenzie, 1996), and a connection between Philippines CAVA climate and volcanism over broader ice age time Pacific scales has been established in regional studies Ocean Easterly stratospheric winds Ecuador (e.g., Jellinek et al., 2004; McGuire et al., 1997; South America Novell et al., 2006; Paterne et al., 1990). How- Peru ever, a general link between glacial cycles and 15°S Tonga global volcanic activity has remained elusive. Australia Westerly TEPHRA RECORD FROM THE “RING stratospheric winds OF FIRE” We analyze marine records of widely dis- New Zealand persed, and well-preserved, tephra layers associated with the Circum-Pacifi c volcanic chain referred to as the “Ring of Fire” (ROF). Figure 1. Bathymetric map of Pacifi c Ocean with red triangles indicating active arc volca- The ROF accounts for about half the global noes along the Pacifi c “Ring of Fire.” Red dots mark DSDP/ODP/IODP (Deep Sea Drilling length of active plate subduction. Ash plumes Project /Ocean Drilling Program / Integrated Ocean Drilling Program) coring sites and Central of highly explosive Plinian eruptions travel American volcanic arc (CAVA) gravity core sites. ODP/DSDP sites are as follows: MD87–2121 and 1124 (New Zealand); 836 and 837 (Tonga Arc); 767–770 (Philippines); 1173 and 1174 (Nan- through the atmosphere and deposit volcanic kai Trough); 192 (Kamchatka); 178, 179, 189, and 190 (Aleutian Islands and Alaska); 1239 and tephras downwind from the eruption sites; 1237 (Ecuador and Peru); Legs 67, 170 and 205 (Central America). Arrows and dashed lines sites included in this study lie 200–500 km mark the predominant global stratospheric wind directions. from their respective sources in the prevailing stratospheric wind directions (Fig. 1). 1GSA Data Repository item 2013055, data, additional fi gures explaining the methods, and an extended er- ror analysis of the data set and statistics, is available online at www.geosociety.org/pubs/ft2013.htm, or on re- *E-mail: [email protected]. quest from [email protected] or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301, USA. GEOLOGY, February 2013; v. 41; no. 2; p. 227–230; Data Repository item 2013055 | doi:10.1130/G33419.1 | Published online 30 November 2012 GEOLOGY© 2012 Geological | February Society 2013 of America.| www.gsapubs.org For permission to copy, contact Copyright Permissions, GSA, or [email protected]. 227 cores. These tephra layers are also dated using ash sequence, and the peak within 14% of the time series is shown in Figure 2B (and by the estimated sedimentation rates. obliquity frequency that rises furthest above the black line in Fig. DR3D). In addition to the peak The time series of ash deposits at a specifi c background continuum in a fractional sense is within the obliquity band, the spectrum exhibits location is based on the individual drill site recorded. To build up a null distribution, this pro- some additional concentration of energy near with the most continuous and complete tephra cedure is repeated 100,000 times, and indicates the 1 per 100 k.y. and 1 per 23 k.y. frequencies. record. Preference is given to drill sites on the that the 6.3 ratio identifi ed for the actual 1 per Although these concentrations contain no sig- incoming plate since these are generally less 44 k.y. peak would be realized less than 1% of nifi cant peaks, the presence of excess energy is affected by erosion than sites on the continental the time, according to our null model. Because in accord with other indicators of late Pleisto- slope. The record is complemented by core data no other process is expected to concentrate cene climate. from adjacent sites if possible. Tephra layers of energy in the band of frequencies that we con- the same age and depositional depth obtained sider, these results constitute a statistically sig- LINKING MILANKOVITCH CYCLES, from sites in close proximity (<50 km) are gen- nifi cant detection of variations in tephra related ICE AGE DYNAMICS AND VOLCANISM erally counted as one eruptive event. Tephras of to the quasi-periodic 1 per 41 k.y. changes in the The foregoing spectral results strongly sug- similar age recorded at sites at greater distance obliquity of Earth’s spin axis. gest that ice-age climate variations induce volca- from one another are counted as separate events. To further evaluate the spectral peak that we nism, and the physical link may be the changes In total, we have identifi ed 408 tephra layers at associate with obliquity, we compress all tephra in crustal stress associated with ice-ocean sites along the ROF. The estimated ages of the ages by a factor of 10%. Compression has the mass redistributions during the glacial cycles tephra layers have uncertainties ranging to 14% largest effect on the absolute ages of the oldest (Glazner et al., 1999; Huybers and Langmuir, of their age. These uncertainties are accounted samples, for which uncertainties are the largest. 2009; Jull and McKenzie, 1996; McGuire et al., for in subsequent analyses. For a detailed dis- The eruption frequency computed on the basis 1997; Sigvaldason et al., 1992). Volcanic output cussion and explanation of the dating and asso- of this compressed time series is given in Fig- would be expected to increase during periods in ciated errors see the Data Repository. ure 2A. The associated power spectrum of this which the local confi ning pressure decreases, FREQUENCY ANALYSIS We mapped the ROF data set into a binary 0.8 0.008 time series in which the occurrence of a tephra A 0.6 0.007 layer is given a value of unity. To display low- 0.4 0.006 frequency variability, we applied a stable-phase, 0.2 0.005 16 0 0.004 running average low-pass fi lter with a width of 14 −0.2 0.003 5 k.y. to the time series (red line in Fig. DR3A in −0.4 0.002 frequency 12 −0.6 0.001 the Data Repository). It is instructive to consider in eruption Variation 10 Normalized obliquity −0.8 0 the spectral estimates associated with a sequence 1 2 3 4 5 6 7 8 9 8 Time (kyr) of progressively older, overlapping 400 k.y. 6 segments of the tephra time series (Fig. DR4), 4 (eruptions/k.y.) which we obtain using a multitaper spectral 2 Eruption frequency analysis (Thomson, 1982; Percival and Walden, 0 1998).
Load more

Recommended publications
  • Extending the Late Holocene White River Ash Distribution, Northwestern Canada STEPHEN D
    ARCTIC VOL. 54, NO. 2 (JUNE 2001) P. 157– 161 Extending the Late Holocene White River Ash Distribution, Northwestern Canada STEPHEN D. ROBINSON1 (Received 30 May 2000; accepted in revised form 25 September 2000) ABSTRACT. Peatlands are a particularly good medium for trapping and preserving tephra, as their surfaces are wet and well vegetated. The extent of tephra-depositing events can often be greatly expanded through the observation of ash in peatlands. This paper uses the presence of the White River tephra layer (1200 B.P.) in peatlands to extend the known distribution of this late Holocene tephra into the Mackenzie Valley, northwestern Canada. The ash has been noted almost to the western shore of Great Slave Lake, over 1300 km from the source in southeastern Alaska. This new distribution covers approximately 540000 km2 with a tephra volume of 27 km3. The short time span and constrained timing of volcanic ash deposition, combined with unique physical and chemical parameters, make tephra layers ideal for use as chronostratigraphic markers. Key words: chronostratigraphy, Mackenzie Valley, peatlands, White River ash RÉSUMÉ. Les tourbières constituent un milieu particulièrement approprié au piégeage et à la conservation de téphra, en raison de l’humidité et de l’abondance de végétation qui règnent en surface. L’observation des cendres contenues dans les tourbières permet souvent d’élargir notablement les limites spatiales connues des épisodes de dépôts de téphra. Cet article recourt à la présence de la couche de téphra de la rivière White (1200 BP) dans les tourbières pour agrandir la distribution connue de ce téphra datant de l’Holocène supérieur dans la vallée du Mackenzie, située dans le Nord-Ouest canadien.
    [Show full text]
  • Explosive Eruptions
    Explosive Eruptions -What are considered explosive eruptions? Fire Fountains, Splatter, Eruption Columns, Pyroclastic Flows. Tephra – Any fragment of volcanic rock emitted during an eruption. Ash/Dust (Small) – Small particles of volcanic glass. Lapilli/Cinders (Medium) – Medium sized rocks formed from solidified lava. – Basaltic Cinders (Reticulite(rare) + Scoria) – Volcanic Glass that solidified around gas bubbles. – Accretionary Lapilli – Balls of ash – Intermediate/Felsic Cinders (Pumice) – Low density solidified ‘froth’, floats on water. Blocks (large) – Pre-existing rock blown apart by eruption. Bombs (large) – Solidified in air, before hitting ground Fire Fountaining – Gas-rich lava splatters, and then flows down slope. – Produces Cinder Cones + Splatter Cones – Cinder Cone – Often composed of scoria, and horseshoe shaped. – Splatter Cone – Lava less gassy, shape reflects that formed by splatter. Hydrovolcanic – Erupting underwater (Ocean or Ground) near the surface, causes violent eruption. Marr – Depression caused by steam eruption with little magma material. Tuff Ring – Type of Marr with tephra around depression. Intermediate Magmas/Lavas Stratovolcanoes/Composite Cone – 1-3 eruption types (A single eruption may include any or all 3) 1. Eruption Column – Ash cloud rises into the atmosphere. 2. Pyroclastic Flows Direct Blast + Landsides Ash Cloud – Once it reaches neutral buoyancy level, characteristic ‘umbrella cap’ forms, & debris fall. Larger ash is deposited closer to the volcano, fine particles are carried further. Pyroclastic Flow – Mixture of hot gas and ash to dense to rise (moves very quickly). – Dense flows restricted to valley bottoms, less dense flows may rise over ridges. Steam Eruptions – Small (relative) steam eruptions may occur up to a year before major eruption event. .
    [Show full text]
  • Canadian Volcanoes, Based on Recent Seismic Activity; There Are Over 200 Geological Young Volcanic Centres
    Volcanoes of Canada 1 V4 C.J. Hickson and M. Ulmi, Jan. 3, 2006 • Global Volcanism and Plate tectonics Where do volcanoes occur? Driving forces • Volcano chemistry and eruption types • Volcanic Hazards Pyroclastic flows and surges Lava flows Ash fall (tephra) Lahars/Debris Flows Debris Avalanches Volcanic Gases • Anatomy of an Eruption – Mt. St. Helens • Volcanoes of Canada Stikine volcanic belt Presentation Outline Anahim volcanic belt Wells Gray – Clearwater volcanic field 2 Garibaldi volcanic belt • USA volcanoes – Cascade Magmatic Arc V4 Volcanoes in Our Backyard Global Volcanism and Plate tectonics In Canada, British Columbia and Yukon are the host to a vast wealth of volcanic 3 landforms. V4 How many active volcanoes are there on Earth? • Erupting now about 20 • Each year 50-70 • Each decade about 160 • Historical eruptions about 550 Global Volcanism and Plate tectonics • Holocene eruptions (last 10,000 years) about 1500 Although none of Canada’s volcanoes are erupting now, they have been active as recently as a couple of 4 hundred years ago. V4 The Earth’s Beginning Global Volcanism and Plate tectonics 5 V4 The Earth’s Beginning These global forces have created, mountain Global Volcanism and Plate tectonics ranges, continents and oceans. 6 V4 continental crust ic ocean crust mantle Where do volcanoes occur? Global Volcanism and Plate tectonics 7 V4 Driving Forces: Moving Plates Global Volcanism and Plate tectonics 8 V4 Driving Forces: Subduction Global Volcanism and Plate tectonics 9 V4 Driving Forces: Hot Spots Global Volcanism and Plate tectonics 10 V4 Driving Forces: Rifting Global Volcanism and Plate tectonics Ocean plates moving apart create new crust.
    [Show full text]
  • Largest Explosive Eruption in Historical Times in the Andes at A.D
    b- Largest explosive eruption in historical times in the Andes at A.D. Huaynaputina volcano, 1600, southern Peru Jean-Claude ThOuret* IRD and Instituto Geofisicodel PerÚ, Calle Calatrava 21 6. Urbanización Camino Real, La Molina, Lima 12, Perú Jasmine Davila Instituto Geofísico del Perú, Lima, Perú Jean-Philippe Eissen IRD Centre de Brest BP 70, 29280 Plouzane Cedex, France ABSTRACT lent [DREI volume. km': Table The The largest esplosive eruption (volcanic explosivity index of 6) in historical times in the 4.4-5.6 I). tephra is composed of -SO% pumice with rhyolitic Andes took place in 1600 at Huaynaputina volcano in southern Peru. According to chroni- A.D. glass, crystals (mostly amphibole and bio- cles, the eruption began on February 19 with a Plinian phase and lasted until March 6. Repeated 15% tite), and 5% xenoliths including hydrothermally tephra falls, pyroclastic flows, and surges devastated an area 70 x 40 kni? west of the vent and altered fragments from the volcanic and sedimen- affected all of southern Peru, and earthquakes shook the city of Arequipa 75 km away. Eight tnry bedrock, and a small amount of accessory lwa deposits, totaling 10.2-13.1 km3 in bulk volume, are attributed to this eruption: (1) a widespread, fragments. The erupted pumice is a white, , -S.1 kn3 pumice-fall deposit; (2) channeled ignimbrites (1.6-2 km3) with (3) ground-surge and medium-potassicdacite (average SiO, and ash-cloud-surge deposits; (4) widespread co-ignimbrite ash layers; (5) base-surge deposits; (6) 63.6% 1.85% hlgO) of the potassic calc-alkalic suite.
    [Show full text]
  • Remotely Assessing Tephra Fall Building Damage and Vulnerability: Kelud Volcano, Indonesia George T
    Williams et al. Journal of Applied Volcanology (2020) 9:10 https://doi.org/10.1186/s13617-020-00100-5 RESEARCH Open Access Remotely assessing tephra fall building damage and vulnerability: Kelud Volcano, Indonesia George T. Williams1,2* , Susanna F. Jenkins1,2, Sébastien Biass1, Haryo Edi Wibowo3,4 and Agung Harijoko3,4 Abstract Tephra from large explosive eruptions can cause damage to buildings over wide geographical areas, creating a variety of issues for post-eruption recovery. This means that evaluating the extent and nature of likely building damage from future eruptions is an important aspect of volcanic risk assessment. However, our ability to make accurate assessments is currently limited by poor characterisation of how buildings perform under varying tephra loads. This study presents a method to remotely assess building damage to increase the quantity of data available for developing new tephra fall building vulnerability models. Given the large number of damaged buildings and the high potential for loss in future eruptions, we use the Kelud 2014 eruption as a case study. A total of 1154 buildings affected by falls 1–10 cm thick were assessed, with 790 showing signs that they sustained damage in the time between pre- and post-eruption satellite image acquisitions. Only 27 of the buildings surveyed appear to have experienced severe roof or building collapse. Damage was more commonly characterised by collapse of roof overhangs and verandas or damage that required roof cladding replacement. To estimate tephra loads received by each building we used Tephra2 inversion and interpolation of hand-contoured isopachs on the same set of deposit measurements.
    [Show full text]
  • Potential Impacts from Tephra Fall to Electric Power Systems: a Review and Mitigation Strategies
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UC Research Repository Bull Volcanol DOI 10.1007/s00445-012-0664-3 REVIEW ARTICLE Potential impacts from tephra fall to electric power systems: a review and mitigation strategies J. B. Wardman & T. M. Wilson & P. S. Bodger & J. W. Cole & C. Stewart Received: 9 May 2012 /Accepted: 20 September 2012 # Springer-Verlag Berlin Heidelberg 2012 Abstract Modern society is highly dependent on a reliable identified to avoid future unplanned interruptions. To ad- electricity supply. During explosive volcanic eruptions, dress this need, we have produced a fragility function that tephra contamination of power networks (systems) can com- quantifies the likelihood of insulator flashover at different promise the reliability of supply. Outages can have signifi- thicknesses of tephra. Finally, based on our review of case cant cascading impacts for other critical infrastructure studies, potential mitigation strategies are summarised. sectors and for society as a whole. This paper summarises Specifically, avoiding tephra-induced insulator flashover known impacts to power systems following tephra falls by cleaning key facilities such as generation sites and trans- since 1980. The main impacts are (1) supply outages from mission and distribution substations is of critical importance insulator flashover caused by tephra contamination, (2) dis- in maintaining the integrity of an electric power system. ruption of generation facilities, (3) controlled outages during tephra cleaning, (4) abrasion and corrosion of exposed Keywords Volcanic ash . Eruption . Electricity . equipment and (5) line (conductor) breakage due to tephra Generation . Transmission . Distribution . Substation loading. Of these impacts, insulator flashover is the most common disruption.
    [Show full text]
  • Volcanoes: the Ring of Fire in the Pacific Northwest
    Volcanoes: The Ring of Fire in the Pacific Northwest Timeframe Description 1 fifty minute class period In this lesson, students will learn about the geological processes Target Audience that create volcanoes, about specific volcanoes within the Ring of Fire (including classification, types of volcanoes, formation process, Grades 4th- 8th history and characteristics), and about how volcanoes are studied and why. For instance, students will learn about the most active Suggested Materials submarine volcano located 300 miles off the coast of Oregon — Axial • Volcanoe profile cards Seamount. This submarine volcano is home to the first underwater research station called the Cabled Axial Seamount Array, from which researchers stream data and track underwater eruptions via fiber optic cables. Students will learn that researchers also monitor Axial Seamount using research vessels and remote operated vehicles. Objectives Students will: • Synthesize and communicate scientific information about specific volcanoes to fellow students • Will learn about geological processes that form volcanoes on land and underwater • Will explore the different methods researchers employ to study volcanoes and related geological activity Essential Questions What are the different processes that create volcanoes and how/why do researchers study volcanic activity? How, if at all, do submarine volcanoes differ from volcanoes on land? Background Information A volcano occurs at a point where material from the inside of the Earth is escaping to the surface. Volcanoes Contact: usually occur along the fault lines that SMILE Program separate the tectonic plates that make [email protected] up the Earth's crust (the outermost http://smile.oregonstate.edu/ layer of the Earth). Typically (though not always), volcanoes occur at one of two types of fault lines.
    [Show full text]
  • Indirect Tephra Volume Estimations Using Theorical Models for Some Chilean Historical Volcanic Eruptions with Sustained Columns J.E
    Indirect tephra volume estimations using theorical models for some Chilean historical volcanic eruptions with sustained columns J.E. Romero*1,2 , J.G. Viramonte 3 & R. A. Scasso 4 (1) Universidad de Atacama, Departamento de Geología. Copayapu 485, Copiapó. (2) Proyecto Archivo Nacional de Volcanes, www.archivonacionaldevolcanes.cl (3) INENCO – GEONORTE Universidad Nacional de Salta-CONICET, Av. Bolivia 5150–4400, Salta , Argentina (4)IGeBA-CONICET, Universidad de Buenos Aires, Departamento de Ciencias Geológicas, Int. Guiraldes 2160, C1428EHA, Ciudad Universitaria, Pab. II, Buenos Aires, Argentina. * Presenting Author’s email: [email protected] Introduction During explosive volcanic eruptions, diverse pyroclastic products are discharged from an eruptive column. Those columns are divided into three zones; 1) a basal gas thrust one, 2) medial convective and 3) a top umbrella region (Sparks, 1986) as is indicated in figure 1a. In this last one, where the column is dispersed laterally and radially forming a dispersion cloud or volcanic plume, the column reaches an Ht region due its momentum (Fig.1a). There has been defined two types of eruptive columns in relation with the time between single explosions. If the time between explosions exceeds the time of ascension of a column until its Ht height, the column is thermal, and in the opposite case, if the ascension time is smaller than the separation between explosions, this column is sustained (Sparks, 1986; Carey and Bursik, 2000). A good agreement has been found in the prediction of column heights and field observations for the case of columns which extends higher than the tropopause (Settle, 1978; Wilson et al, 1978; Sparks and Wilson, 1982; Sparks, 1986).
    [Show full text]
  • Preservation of Thin Tephra Russell Blong1* , Neal Enright2 and Paul Grasso3
    Blong et al. Journal of Applied Volcanology (2017) 6:10 DOI 10.1186/s13617-017-0059-4 RESEARCH Open Access Preservation of thin tephra Russell Blong1* , Neal Enright2 and Paul Grasso3 Abstract The preservation of thin (<300 mm thick) tephra falls was investigated at four sites in Papua New Guinea (PNG), Alaska and Washington, USA. Measurements of the variations in the thickness of: (i) Tibito Tephra 150 km downwind from the source, Long Island (PNG) erupted mid-seventeenth century; (ii) St Helens W tephra (erupted 1479–80 A.D.) on the slopes of the adjacent Mt. Rainier in Washington State; (iii) Novarupta (1912) tephra preserved on Kodiak Island (Alaska, USA); and (iv) an experimentally placed tephra at a site near Mt. Hagen (PNG) allow tentative conclusions to be drawn about the relative importance to tephra preservation of slope gradients, vegetation cover and soil faunal activity. Results for the experimental tephra suggest that compaction occurs rapidly post-deposition and that estimates of tephra thickness and bulk density need to indicate how long after deposition thickness measurements were made. These studies show that erosional reworking of thin tephra is not rapid even on steeper slopes in high rainfall environments. In Papua New Guinea a 350-year old tephra is rarely present under forest but is well-preserved under alpine grasslands. On Mt. Rainier 500-year old tephra is readily preserved under forest but absent under grasslands as a result of gopher activity. Despite the poor relationship between tephra thickness and slope steepness the thickness of thin tephras is highly variable. On Kodiak Island thickness variability across a few metres is similar to that observed across the whole northeast of the island.
    [Show full text]
  • Significance of a Near-Source Tephra-Stratigraphic Sequence to the Eruptive History of Hayes Volcano, South- Central Alaska
    Significance of a Near-Source Tephra-Stratigraphic Sequence to the Eruptive History of Hayes Volcano, South- Central Alaska Scientific Investigations Report 2014–5133 U.S. Department of the Interior U.S. Geological Survey FRONT COVER Portion of the Hayes River outcrop 31 km northeast of Hayes Volcano, along the Hayes River immediately downstream from the terminus of Hayes Glacier. Photograph by Andrew Calvert, 2011. Significance of a Near-Source Tephra- Stratigraphic Sequence to the Eruptive History of Hayes Volcano, South-Central Alaska By Kristi L. Wallace, Michelle L. Coombs, Leslie A. Hayden, and Christopher F. Waythomas Scientific Investigations Report 2014–5133 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2014 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit http://www.usgs.gov or call 1–888–ASK–USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/ pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may containcopyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.
    [Show full text]
  • Volcanic Impacts on Grasslands – a Review
    Volcanic impacts on grasslands – a review Arnalds Ó. Agricultural University of Iceland Corresponding author: [email protected] Abstract Volcanic eruptions have a wide range of effects on many of the Earth’s grassland systems, such as in Africa, the Americas and Iceland. The effects are determined by the severity of the impact, vegetation height and the resilience of the impacted system. Biological soil crusts, often an important component of dryland grazing systems, are severely affected by thin deposition of volcanic ash, whereas taller vegetation with ample nutrient supplies is more tolerant to such disturbances. Redistribution of airborne unconsolidated volcanic materials (tephra, including volcanic ash) in the aftermath of eruptions is often quite harmful to ecosystem survival. The interaction between volcanic events and land-use practices such as grazing is detrimental. Alien plant species in volcanic areas can severely interfere with ecosystem recovery. Keywords: tephra, volcanic ash, volcanic impact, grazing Introduction There are 1545 active volcanoes with >9000 eruptions listed in the current Smithsonian Catalog of Active Volcanoes (Siebert et al., 2010). About 70 volcanoes are active each year on average, but most eruptions are small. The majority of volcanoes occur at the margins of tectonic plates, which account for 94% of the volcanic activity, with the ‘Pacific Ring of Fire’ and the African Rift Valley being good examples (Simkin and Siebert, 2000). The activity occurs also in relation to so-called hot spots, which are isolated and transfer heat from the mantle (Bjarnason, 2008), such as on the islands of Hawaii, Galapagos and Iceland, and in Yellowstone, which is an example of intra-continental volcanic hot-spot activity.
    [Show full text]
  • Geospatial Distribution of Tephra Fall in Alaska: a Geodatabase Compilation of Published Tephra Fall Occurrences from the Pleistocene to the Present
    GEOSPATIAL DISTRIBUTION OF TEPHRA FALL IN ALASKA: A GEODATABASE COMPILATION OF PUBLISHED TEPHRA FALL OCCURRENCES FROM THE PLEISTOCENE TO THE PRESENT Katherine M. Mulliken, Janet R. Schaefer, Cheryl E. Cameron Miscellaneous Publication 164 $5.00 This publication is PRELIMINARY in nature and meant to allow rapid release of field observations or initial interpretations of geology or analytical data. It has undergone limited peer review, but does not necessarily conform to DGGS editorial standards. Interpretations or conclusions contained in this publication are subject to change. March 2018 State of Alaska Department of Natural Resources Division of Geological & Geophysical Surveys STATE OF ALASKA Bill Walker, Governor DEPARTMENT OF NATURAL RESOURCES Andrew T. Mack, Commissioner DIVISION OF GEOLOGICAL & GEOPHYSICAL SURVEYS Steve Masterman, State Geologist & Director Publications produced by the Division of Geological & Geophysical Surveys are available for free download from the DGGS website (dggs.alaska.gov). Publications on hard-copy or digital media can be examined or purchased in the Fairbanks office: Alaska Division of Geological & Geophysical Surveys (DGGS) 3354 College Road | Fairbanks, Alaska 99709-3707 Phone: 907.451.5010 | Fax 907.451.5050 [email protected] | dggs.alaska.gov DGGS publications are also available at: Alaska State Library, Historical Collections & Talking Book Center 395 Whittier Street Juneau, Alaska 99801 Alaska Resource Library and Information Services (ARLIS) 3150 C Street, Suite 100 Anchorage, Alaska 99503 Suggested citation: Mulliken, K.M., Schaefer, J.R., and Cameron, C.E., 2018, Geospatial distribution of tephra fall in Alaska: a geodatabase compilation of published tephra fall occurrences from the Pleistocene to the present: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 164, 46 p.
    [Show full text]