DOCSLIB.ORG

SIR 2020-5043: Chemical Evaluation of Water and Gases Collected from Hydrothermal Systems Located in the Central Aleutian Arc, A

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
SIR 2020-5043: Chemical Evaluation of Water and Gases Collected from Hydrothermal Systems Located in the Central Aleutian Arc, A Chemical Evaluation of Water and Gases Collected from Hydrothermal Systems Located in the Central Aleutian Arc, August 2015 Scientific Investigations Report 2020–5043 U.S. Department of the Interior U.S. Geological Survey Cover. Photograph of Christoph Kern (U.S. Geological Survey) taking gas measurements between large gas plumes on Geyser Bight, Umnak Island, Alaska. Photograph by Cynthia Werner. Back cover. Photograph of the northern interior of Fisher Caldera on Unimak Island, Alaska. The view is from mount Finch looking west-southwest. Photograph by Cynthia Werner. Chemical Evaluation of Water and Gases Collected from Hydrothermal Systems Located in the Central Aleutian Arc, August 2015 By Cynthia Werner, Christoph Kern, and Peter Kelly Scientific Investigations Report 2020–5043 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DAVID BERNHARDT, Secretary U.S. Geological Survey James F. Reilly II, Director U.S. Geological Survey, Reston, Virginia: 2020 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 https://www.usgs.gov or call 1–888–ASK–USGS (1–888–275–8747). For an overview of USGS information products, including maps, imagery, and publications, visit https://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 contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Werner, C., Kern, C., and Kelly, P. K., 2020, Chemical evaluation of water and gases collected from hydrothermal systems located in the central Aleutian arc, August 2015: U.S. Geological Survey Scientific Investigations Report 2020–5043, 35 p., https://doi.org/10.3133/sir20205043. ISSN 2328-0328 (online) iii Acknowledgments The authors gratefully acknowledge the contributions from John Power, Deb Bergfeld, Laura Clor, Pete Stelling, and Bill Evans for their help with project planning and funding negotiations, field work preparations, analytical support, and for reviewing this report. We also gratefully acknowledge the careful review by Taryn Lopez and Phil Frederick. The authors would also like to thank JoJo Mangano for his skill in redrafting the map figures. The work would not have been possible without the field logistical support provided by Maritime Helicopters, Homer, Alaska. Funding was provided by the Alaska Volcano Observatory, the Deep Carbon Observatory, and the National Science Foundation (Grant # EAR-1456939 to Diana Roman, Erik Hauri, and Terry Plank). The science team are very grateful for the support received from Maritime Helicopter’s research vessel Maritime Maid and crew, and the Bell 407 helicopter, skillfully piloted by Dan Leary. Contents Acknowledgments ........................................................................................................................................iii Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Methods...........................................................................................................................................................1 Water Sampling .....................................................................................................................................1 Gas Sampling .........................................................................................................................................2 Chemical Analyses ...............................................................................................................................3 Additional Measurements on Site—MultiGAS ................................................................................3 Makushin Volcano .........................................................................................................................................4 Makushin Valley ....................................................................................................................................5 Glacial Valley .........................................................................................................................................6 Water Chemistry Summary .................................................................................................................6 Gas Chemistry Summary......................................................................................................................8 Carbon and Helium Isotopes ......................................................................................................9 Gas Geothermometry ................................................................................................................10 Apparent Decline in Hydrothermal Activity at Makushin Volcano since the 1980s .......10 Future Study Recommendations ......................................................................................................10 Akutan Volcano ............................................................................................................................................11 Water Chemistry Summary ...............................................................................................................12 Fluid Geothermometry ...............................................................................................................12 Gas Chemistry Summary....................................................................................................................14 Carbon and Helium Isotopes ....................................................................................................17 Gas Geothermometry ................................................................................................................17 Future Study Recommendations ......................................................................................................17 Tana Volcano ................................................................................................................................................17 Water Chemistry Summary ...............................................................................................................18 Gas Chemistry Summary....................................................................................................................20 Carbon and Helium Isotopes ....................................................................................................20 Gas Geothermometry ................................................................................................................20 Future Study Recommendations ......................................................................................................20 Fisher Caldera...............................................................................................................................................22 Mount Finch and Caldera Sampling ................................................................................................23 iv Water Chemistry Summary ...............................................................................................................24 Gas Chemistry Summary....................................................................................................................26 Carbon and Helium Isotopes ....................................................................................................26 Gas Geothermometry ................................................................................................................26 Future Study Recommendations ......................................................................................................27 Geyser Bight Hydrothermal Area ..............................................................................................................27 Water Chemistry Summary ...............................................................................................................29 Fluid Geothermometry ...............................................................................................................31 Gas Chemistry Summary....................................................................................................................31 Carbon and Helium Isotopes ....................................................................................................32 Future Study Recommendations ......................................................................................................32 Conclusions...................................................................................................................................................32 References Cited..........................................................................................................................................33 Figures 1. Map showing the central Aleutian Islands and general sample locations from this study ................................................................................................................................................2
Load more

Recommended publications
  • Aleutian Islands
    Journal of Global Change Data & Discovery. 2018, 2(1): 109-114 © 2018 GCdataPR DOI:10.3974/geodp.2018.01.18 Global Change Research Data Publishing & Repository www.geodoi.ac.cn Global Change Data Encyclopedia Aleutian Islands Liu, C.1* Yang, A. Q.2 Hu, W. Y.1 Liu, R. G.1 Shi, R. X.1 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; 2. Institute of Remote Sensing and Digital Earth，Chinese Academy of Sciences，Beijing100101，China Keywords: Aleutian Islands; Fox Islands; Four Mountains Islands; Andreanof Islands; Rat Islands; Near Islands; Kommandor Islands; Unimak Island; USA; Russia; data encyclopedia The Aleutian Islands extends latitude from 51°12′35″N to 55°22′14″N and longitude about 32 degrees from 165°45′10″E to 162°21′10″W, it is a chain volcanic islands belonging to both the United States and Russia[1–3] (Figure 1, 2). The islands are formed in the northern part of the Pacific Ring of Fire. They form part of the Aleutian Arc in the Northern Pacific Ocean, extending about 1,900 km westward from the Alaska Peninsula to- ward the Kamchatka Peninsula in Russia, Figure 1 Dataset of Aleutian Islands in .kmz format and mark a dividing line between the Ber- ing Sea to the north and the Pacific Ocean to the south. The islands comprise 6 groups of islands (east to west): the Fox Islands[4–5], islands of Four Mountains[6–7], Andreanof Islands[8–9], Rat Islands[10–11], Near Is- lands[12–13] and Kommandor Islands[14–15].
    [Show full text]
  • Groundfish Harvest from Parallel Seasons in the Bering Sea-Aleutian Islands Area
    Fishery Management Report No. 08-43 Bering Sea-Aleutian Islands Area State-Waters Groundfish Fisheries and Groundfish Harvest from Parallel Seasons in 2007 by Krista Milani August 2008 Alaska Department of Fish and Game Divisions of Sport Fish and Commercial Fisheries Symbols and Abbreviations The following symbols and abbreviations, and others approved for the Système International d'Unités (SI), are used without definition in the following reports by the Divisions of Sport Fish and of Commercial Fisheries: Fishery Manuscripts, Fishery Data Series Reports, Fishery Management Reports, and Special Publications. All others, including deviations from definitions listed below, are noted in the text at first mention, as well as in the titles or footnotes of tables, and in figure or figure captions. Weights and measures (metric) General Measures (fisheries) centimeter cm Alaska Administrative fork length FL deciliter dL Code AAC mideye to fork MEF gram g all commonly accepted mideye to tail fork METF hectare ha abbreviations e.g., Mr., Mrs., standard length SL kilogram kg AM, PM, etc. total length TL kilometer km all commonly accepted liter L professional titles e.g., Dr., Ph.D., Mathematics, statistics meter m R.N., etc. all standard mathematical milliliter mL at @ signs, symbols and millimeter mm compass directions: abbreviations east E alternate hypothesis HA Weights and measures (English) north N base of natural logarithm e cubic feet per second ft3/s south S catch per unit effort CPUE foot ft west W coefficient of variation CV gallon gal copyright © common test statistics (F, t, χ2, etc.) inch in corporate suffixes: confidence interval CI mile mi Company Co.
    [Show full text]
  • Grea3tfpermhl RESOURCES of the ALEUTIAN ARC
    GrEa3TFPERMhL RESOURCES OF THE ALEUTIAN ARC Wy Roman .I. Mntylcw, RlairB~yA. Lics, Chri~',Boph~r.I. WYC, and Mary A. Moomnsa GEOTHERMAL RESOURCES OF THE ALEUTIAN ARC By Roman J. Motyka, Shirley A. Liss, Christopher J. Nye, and Mary A. Moorman Roman Motyka sampling an upper Glacier Valley hot spring in the Makushin geothermal area. Photo by Shirley Liss. Professional Report 114 Division of Geological & Geophysical Surveys Cover photo: "Old Faithful" of the Geyser Bight geothermal resource area. When- ever it has been observed (1870, 1948, 1980, and 1988),spring G8, Fairbanks, Alaska shown here at maximum activity, has had an eruption cycle of 1993 12 minutes. Photo by Shirley Liss. STATE OF ALASKA Walter J. Hickel, Governor DEPARTMENT OF NATURAL RESOURCES Harry A. Noah, Commissioner DIVISION OF GEOLOGICAL & GEOPHYSICAL SURVEYS Thomas E. Smith, State Geologist Division of Geological & GeophysicalSurveys publications can be inspected at the following locations. Address mail orders to the Fairbanks office. Alaska Division of Geological University of Alaska Anchorage Library & Geophysical Surveys 321 1 Providence Drive 794 University Avenue, Suite 200 Anchorage, Alaska 99508 Fairbanks, Alaska 99709-3645 Elmer E. Rasmuson Library Alaska Resource Library University of Alaska Fairbanks 222 W. 7th Avenue Fairbanks, Alaska 99775-1005 Anchorage, Alaska 995 13-7589 Alaska State Library State Office Building, 8th moor 333 Willoughby Avenue Juneau, Alaska 9981 1-0571 This publication released by the Division of Geological & Geophysical Surveys, was
    [Show full text]
  • Geology of Umnak and Bogoslof Islands Aleutian Islands Alaska
    Geology of Umnak and Bogoslof Islands Aleutian Islands Alaska By F. M. BYERS, JR. INVESTIGATIONS OF ^ALASKAN VOLCANOES GEOLOGICAL SURVEY BULLETIN 1028-L Prepared in cooperation with the Office, Chief of Engineers, U.S. Army UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1959 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. PEEFACE In October 1945 the War Department (now Department of the Army) requested the Geological Survey to undertake a program of volcano investigations in the Aleutian Islands-Alaska Peninsula area. Field studies under general direction of G. D. Robinson, were begun as soon as weather permitted in the spring of 1946. The results of the first year's field, laboratory, and library work were assembled as two administrative reports. Part of the data was published in 1950 in Geological Survey Bulletin 974-B, "Volcanic Activity in the Aleutian Arc", by Robert R. Coats. The rest of the data has been included in Bulletin 1028. The geologic investigations covered by this report were recon­ naissance. The factual information presented is believed to be accu­ rate, but many of the tentative interpretations and conclusions will be modified as the investigations continue and knowledge grows. The investigations of 1946 were supported almost entirely by the Military Intelligence Division of the Office, Chief of Engineers, U.S. Army. The Geological Survey is indebted to that Office for its early recognition of the value of geologic studies in the Aleutian region, which made this report possible, and for its continuing support.
    [Show full text]
  • Silicic Magma Chambers and Mafic Dikes a Dissertation Submitted to the Department Of
    INVESTIGATIONS OF MAGMATIC END-MEMBERS: SILICIC MAGMA CHAMBERS AND MAFIC DIKES A DISSERTATION SUBMITTED TO THE DEPARTMENT OF GEOLOGICAL AND ENVIRONMENTAL SCIENCES AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Gwyneth Retta Hughes May 2010 © 2010 by Gwyneth Retta Hughes. All Rights Reserved. Re-distributed by Stanford University under license with the author. This work is licensed under a Creative Commons Attribution- Noncommercial 3.0 United States License. http://creativecommons.org/licenses/by-nc/3.0/us/ This dissertation is online at: http://purl.stanford.edu/cf090yt6229 Includes supplemental files: 1. Caldera references for Chapters 2 and 3 (Caldera_index_ref.pdf) 2. Bayes Classifier Code for Chapter 3 (bayes_classifier.zip) 3. Caldera data for Chapter 2 (Arc_caldera_data.csv) 4. Caldera data for Chapter 3 (All_caldera_data.csv) ii I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Gail Mahood, Primary Adviser I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. David Pollard I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Paul Segall Approved for the Stanford University Committee on Graduate Studies. Patricia J. Gumport, Vice Provost Graduate Education This signature page was generated electronically upon submission of this dissertation in electronic format.
    [Show full text]
  • THE ALEUTIAN ISLANDS: THEIR PEOPLE and NATURAL HISTORY
    SMITHSONIAN INSTITUTION WAR BACKGROUND STUDIES NUMBER TWENTY-ONE THE ALEUTIAN ISLANDS: THEIR PEOPLE and NATURAL HISTORY (With Keys for the Identification of the Birds and Plants) By HENRY B. COLLINS, JR. AUSTIN H. CLARK EGBERT H. WALKER (Publication 3775) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION FEBRUARY 5, 1945 BALTIMORE, MB., U„ 8. A. CONTENTS Page The Islands and Their People, by Henry B. Collins, Jr 1 Introduction 1 Description 3 Geology 6 Discovery and early history 7 Ethnic relationships of the Aleuts 17 The Aleutian land-bridge theory 19 Ethnology 20 Animal Life of the Aleutian Islands, by Austin H. Clark 31 General considerations 31 Birds 32 Mammals 48 Fishes 54 Sea invertebrates 58 Land invertebrates 60 Plants of the Aleutian Islands, by Egbert H. Walker 63 Introduction 63 Principal plant associations 64 Plants of special interest or usefulness 68 The marine algae or seaweeds 70 Bibliography 72 Appendix A. List of mammals 75 B. List of birds 77 C. Keys to the birds 81 D. Systematic list of plants 96 E. Keys to the more common plants 110 ILLUSTRATIONS PLATES Page 1. Kiska Volcano 1 2. Upper, Aerial view of Unimak Island 4 Lower, Aerial view of Akun Head, Akun Island, Krenitzin group 4 3. Upper, U. S. Navy submarine docking at Dutch Harbor 4 Lower, Village of Unalaska 4 4. Upper, Aerial view of Cathedral Rocks, Unalaska Island 4 Lower, Naval air transport plane photographed against peaks of the Islands of Four Mountains 4 5. Upper, Mountain peaks of Kagamil and Uliaga Islands, Four Mountains group 4 Lower, Mount Cleveland, Chuginadak Island, Four Mountains group ..
    [Show full text]
  • Fisher Caldera, Unimak Island, Aleutians
    Journal of Volcanology and Geothermal Research 111 (2001) 35±53 www.elsevier.com/locate/jvolgeores Low-d 18O tephra from a compositionally zoned magma body: Fisher Caldera, Unimak Island, Aleutians Ilya N. Bindeman*, John H. Fournelle, John W. Valley Department of Geology and Geophysics, University of Wisconsin, 1215 West Dayton Street, Madison, WI 53706, USA Received 13 August 2000; revised 21 January 2001; accepted 20 February 2001 Abstract We present the results of an oxygen isotope study of phenocrysts in pumice clasts and ash layers produced by the 9100 yr BP composite dacite-basaltic andesite climactic eruption that formed Fisher Caldera in the eastern Aleutians. Products of the eruption represent a low-d 18O magma with d 18O plagioclase (14.79 ^ 0.24½) and clinopyroxene (3.81 ^ 0.23½) correspond- ing to equilibrium at magmatic temperatures. Dacitic and overlying basaltic±andesitic tephra of the climactic eruption, subsequent intracaldera basaltic to andesitic lavas, and a cumulate inclusion, are similarly low in d 18O. Other analyzed lavas and pyroclastics of Unimak island and the lower Alaska peninsula, as well as precaldera Fisher basalt, have normal d 18O magmatic values (.15.5½). We propose a model in which prior to 9100 yr BP, normal mantle-derived basaltic magma coalesced in a large shallow precaldera magma chamber during Late Wisconsin glaciation. Lowering of magmatic d 18O resulted then from long-term assimilation of ,5±10% of syn-glacial hydrothermally-altered country rocks. Differentiation of basaltic magma was concurrent with this assimilation and produced low-d 18O Fisher dacites, cumulates, and post-caldera crystal-richer lavas.
    [Show full text]
  • Image Acquisition in 2016
    ShoreZone Imaging and Mapping 2016 Kalen Morrow Coastal and Ocean Resources Umnak Island – Bering Sea ShoreZone Partner Meeting - October 2016 Aleutian Islands - Day 1 - April 8, 2016 Day 1 – Beaver Inlet, Unalaska Island Day 1 - Unalaska Day 1 – Unalaska Airport Day 2 – April 9, 2016 Day 2 – Akun Island Day 2 – Akutan Day 2 – Tigalda Island Day 2 – Akun Island Day 3 – April 10, 2016 Day 3 – Sedanka Island Day 4 – April 11, 2016 Day 4 – Fort Glenn, Umnak Island Day 4 – Umnak Island, Bering Sea Day 4 – Umnak Island, Bering Sea Day 4 – Nikolski Day 5 – April 12, 2016 Day 5 – Unalaska Island, Pacific Ocean Day 5 - Unalaska Island, Bering Sea Day 6 – April 13, 2016 Day 6 – Unalaska Island, Snow Squall Day 6 – Akutan Island, Lava Field Day 6 – Cathedral Rocks, Unalaska Island Day 7 – April 14, 2016 Day 7 – Official Team Photo Day 7 – Unalaska Island, Bering Sea Day 7 – Western End of Unalaska Island Alaska Peninsula Alaska Peninsula - Day 1 - May 5, 2016 Day 1 – Liftoff Day 1 – Williwaw on Wide Bay Day 1 – Alinchak Bay Day 1 – Landing Day 2 – May 6, 2016 Day 2 – Imuya Bay Day 2 – Wide Bay Day 3 – May 7, 2016 Day 3 – Chignik Day 3 – Nakalilok Bay Day 4 – May 8, 2016 Day 4 – Chirikof Island Day 4 – Semidi Islands Day 5 – May 9, 2016 Day 5 – Kuiukta Bay Day 5 – Devils Bay Day 6 – May 10, 2016 Day 6 – Kujulik Bay Day 6 – Hook Bay Day 7 – May 11, 2016 Day 7 – Chankliut Island Day 7 – Ross Cove Mammals Mammals Kuskokwim Bay, Yukon Delta Mapping Trees and Shrubs BioBand Kuskokwim Bay, Yukon Delta Mapping Estimated Actual Shoreline 2014 2 750 m 3 Shoreline Matches 2003 Aerial Image 1 2 3 1 Best Available Shoreline 2014 ShoreZone Imagery Umnak Island – Bering Sea [email protected].
    [Show full text]
  • Mexican Border to Dixon Entrance NOAA Chart 501
    BookletChart™ West Coast of North America – Mexican Border to Dixon Entrance NOAA Chart 501 A reduced-scale NOAA nautical chart for small boaters When possible, use the full-size NOAA chart for navigation. Published by the Navigation among the islands is beset by frequent fogs, strong and treacherous currents, and tide rips that may be dangerous for small National Oceanic and Atmospheric Administration craft. Because of the frequent fogs and strong currents it is emphasized National Ocean Service that navigation is safe only by frequent sounding and constant reference Office of Coast Survey to the chart. All waters are clear for large ships beyond about 1 mile from the shores, and for small craft beyond 0.25 mile except where www.NauticalCharts.NOAA.gov obstructions are charted. It is not safe to attempt passage inside any of 888-990-NOAA the off-lying rocks. In Samalga Pass, between Samalga Island and the Four Mountains What are Nautical Charts? Group, the waters are deep and 15 miles in width; however, a good berth must be given the shoals that extend SW from Samalga Island. Nautical charts are a fundamental tool of marine navigation. They show A bank, with a minimum depth of 13 fathoms, is about 5.5 miles S of water depths, obstructions, buoys, other aids to navigation, and much Concord Point, Chuginadak Island. Apparently it is the high spot of a more. The information is shown in a way that promotes safe and large shoal area rather than a pinnacle. efficient navigation. Chart carriage is mandatory on the commercial It is strongly recommended that a vessel proceeding along the N side of ships that carry America’s commerce.
    [Show full text]
  • Lauren J. Davies
    The development of a Holocene cryptotephra framework in northwestern North America by Lauren J. Davies A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Earth and Atmospheric Sciences University of Alberta © Lauren J. Davies, 2018 Abstract This thesis contributes to the development of a cryptotephra framework in northwestern North America, providing the initial data for the construction of a regional cryptotephra framework where key cryptotephra layers (those which are widely distributed, easily correlated, and have well constrained chronological control) are identified for use as chronostratigraphic tools. Three aims are outlined: addressing geographical gaps for cryptotephra records in northwestern Canada; defining regionally significant cryptotephra beds that can be used to improve local and regional s chronologies; and demonstrating the potential for cryptotephra as isochrons in the area. Previous knowledge of cryptotephra in the area and any tephra with potential to be transported and preserved distally is summarised, including reference geochemical major element glass datasets and Bayesian age modelling of quality-assessed bounding dates. Previously published data is reviewed and supplemented using new data produced at the University of Alberta. This represents an important summary and evaluation of tephra data for nineteen beds from Alaska and the Yukon. A new cryptotephra record covering ~10,400 cal yr BP is presented from a soligenic peatland in north-central Yukon. Seventy-five tephra peaks are identified during the Holocene, and detailed discussion, including modelled ages and geochemical major element glass datasets, is given for fifty-two samples representing sixty-four geochemical populations. A total of thirty-four tephra identified have a combination of significant glass concentrations, distinctive geochemical data, useful stratigraphic positions/timings, and potential correlation to other known records over a wide area.
    [Show full text]
  • Subsistence Harvests and Uses of Bird and Eggs in Four Communities of the Aleutian Island Area: Akutan, False Pass, Nelson Lagoo
    Subsistence Harvests and Uses of Birds and Eggs in Four Communities of the Aleutian Islands Area: Akutan, False Pass, Nelson Lagoon, and Nikolski James A. Fall, Amy Paige, Vicki Vanek, and Louis Brown Technical Paper No. 243 Division of Subsistence Alaska Department of Fish and Game Juneau, Alaska September 1998 ADA PUBLICATIONS STATEMENT The Alaska Department of Fish and Game operates all of its public programs and activities free from discrimination on the basis of sex, color, race, religion, national origin, age, marital status, pregnancy, parenthood, or disability. For information on alternative formats available for this and other department publications, please contact the department ADA Coordinator at (voice) 907- 465-4120, (TDD) l-800-478-3548 or (fax) 907-586-6595. Any person who believes she or he has been discriminated against should write to: Alaska Department of Fish and Game PO Box 25526 Juneau, AK 99802-5526. or O.E.O. U.S. Department of the interior Washington, D.C. 20240 ABSTRACT In 1997, the Division of Subsistence of the Alaska Department of Fish and Game conducted systematic household interviews on the harvest and use of birds and eggs in four communities of the Aleutian Islands area. The study communities were Akutan, False Pass, Nelson Lagoon, and Nikolski. The research was supported through a cooperative agreement with the United States Fish and Wildlife Service. The interviews were structured by a survey instrument modeled on those previously administered by the division in the four study communities, as well as in other communities of the Aleutian Islands and southwest and Southcentral Alaska.
    [Show full text]
  • Volcanic Explosivity Index (VEI) 7 Eruptions and Their Chilling Impacts GEOSPHERE; V
    Research Paper THEMED ISSUE: Subduction Top to Bottom 2 GEOSPHERE Anticipating future Volcanic Explosivity Index (VEI) 7 eruptions and their chilling impacts GEOSPHERE; v. 14, no. 2 Chris Newhall1, Stephen Self2, and Alan Robock3 1Mirisbiris Garden and Nature Center, Sitio Mirisbiris, Barangay Salvacion, Santo Domingo, Albay 4508, Philippines doi:10.1130/GES01513.1 2Department of Earth & Planetary Science, University of California, 307 McCone Hall, Berkeley, California 94720-4767, USA 3Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, USA 7 figures; 3 tables CORRESPONDENCE: cgnewhall@ gmail .com ABSTRACT INTRODUCTION CITATION: Newhall, C., Self, S., and Robock, A., 2018, Worst-case or high-end subduction-related earthquakes and tsunamis Explosive volcanic eruptions occur in a wide range of sizes, and the mod- Anticipating future Volcanic Explosivity Index (VEI) 7 eruptions and their chilling impacts: Geosphere, v. 14, of 2004 and 2011 are painfully fresh in our memories. High-end subduction- ern world has not yet seen an eruption of either Volcanic Explosivity Index no. 2, p. 1–32, doi:10.1130/GES01513.1. related volcanic eruptions have not occurred in recent memory, so we review (VEI) 7 or 8, the highest 2 orders of magnitude known from written and geo- historical and geologic evidence about such eruptions that will surely recur logic history (Newhall and Self, 1982; Mason et al., 2004; Global Volcanism Science Editor: Shanaka de Silva within coming centuries. Specifically, we focus on Volcanic Explosivity Index Program, 2013). Most, although not all, of these very large eruptions have oc- Guest Associate Editor: Robert Stern (VEI) 7 eruptions, which occur 1–2 times per thousand years.
    [Show full text]