DOCSLIB.ORG

Licht and Hemming 2017.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Licht and Hemming 2017.Pdf Quaternary Science Reviews 164 (2017) 1e24 Contents lists available at ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev Invited review Analysis of Antarctic glacigenic sediment provenance through geochemical and petrologic applications * Kathy J. Licht a, , Sidney R. Hemming b a Department of Earth Sciences, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA b Department of Earth and Environmental Sciences, Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA article info abstract Article history: The number of provenance studies of glacigenic sediments in Antarctica has increased dramatically over Received 2 October 2016 the past decade, providing an enhanced understanding of ice sheet history and dynamics, along with the Received in revised form broader geologic history. Such data have been used to assess glacial erosion patterns at the catchment 10 February 2017 scale, flow path reconstructions over a wide range of scales, and ice sheet fluctuations indicated by Accepted 6 March 2017 iceberg rafted debris in circumantarctic glacial marine sediments. It is notable that even though most of the bedrock of the continent is ice covered and inaccessible, provenance data can provide such valuable information about Antarctic ice and can even be used to infer buried rock types along with their geo- and Keywords: Glacial geology thermochronologic history. Glacigenic sediments provide a broader array of provenance analysis op- Bedrock geology portunities than any other sediment type because of their wide range of grain sizes, and in this paper we Till review methods and examples from all size fractions that have been applied to the Antarctic glacigenic Ice-rafted debris sedimentary record. Interpretations of these records must take careful consideration of the choice of Sediment transport analytical methods, uneven patterns of erosion, and spatial variability in sediment transport and rock Petrography types, which all may lead to a preferential identification of different elements of sources in the prove- Geochronology nance analyses. Because of this, we advocate a multi-proxy approach and highlight studies that Radiogenic isotopes demonstrate the value of selecting complementary provenance methods. Thermochronology © 2017 Elsevier Ltd. All rights reserved. 1. Introduction bedrock geology. Bedrock geology influences erosion rates and ice flow (e.g., Jamieson et al., 2010; Golledge et al., 2013), and the The persistence of the Antarctic ice sheet through warm inter- lithological and geochemical/geochronological expressions of the glacial periods sets it apart from most continental-scale northern geologic history of sediment sources provide important tools for hemisphere ice sheets. While Antarctica provides important op- tracing the transport pathways of sediment (e.g., Licht and Palmer, portunities to directly study modern ice dynamics and geomorphic 2013; Pierce et al., 2014) and for probing erosion rates and thus processes, we cannot rely as readily on the glacial geomorphology inferring landform evolution of hidden sources (e.g., Thomson to reconstruct its past configuration as pioneering naturalists et al., 2013). Schimper, Charpentier, Agassiz, Chamberlain and others used in the On glacial-interglacial timescales, changes in Antarctic ice sheet 1800's to begin to understand the history and influence of glacier volume have resulted in eustatic sea level changes causing major ice on the landscape. Although tremendous progress has been changes locally to the geomorphology and deposition on conti- made in understanding Antarctic ice with multibeam swath nental shelves around Antarctica, but also, globally as coastlines bathymetric data that provided paradigm-shifting images of the shifted, altering ocean currents and fluvial gradients. This link to continental shelf geomorphology (e.g., Shipp et al., 1999), targeted global sea level changes strongly motivates ongoing study of sampling of glacial landforms, comparable to terrestrial glacial Antarctica ice sheets to inform models that can more reliably es- studies, has been difficult to achieve. Glacial geologists working in timate the potential for future sea level rise, an area of substantial the Antarctic also lack the ‘luxury’ of having direct access to the uncertainty (Church et al., 2013). Many of the first-order questions of Antarctic ice sheet history (i.e., ice sheet extent), particularly for the last glacial maximum (LGM), have been addressed (e.g., RAISED * Corresponding author. consortium, 2014) and data-driven numerical models have been E-mail address: [email protected] (K.J. Licht). developed that attempt to optimize model outputs with existing http://dx.doi.org/10.1016/j.quascirev.2017.03.009 0277-3791/© 2017 Elsevier Ltd. All rights reserved. 2 K.J. Licht, S.R. Hemming / Quaternary Science Reviews 164 (2017) 1e24 geologic data on ice extent and flow pathways (e.g., Golledge et al., (origin and transport). 2013)(Fig. 1). However, many fundamental questions about ice In this review we use the term “sediment provenance” or sheet extent and configuration remain even for the last deglacia- “provenance analysis” in the most general sense: it is the recon- tion, and there is a particularly sparse record for pre-LGM times. struction of the origin of sediment, that is the sources and processes The limited exposure of pre-LGM deposits onshore, and limited on the landscape from which the sediment was derived. Prove- access to offshore deposits means that relatively few samples have nance analysis has been widely used in glaciated areas of the been analyzed. Thus reconstructions mainly rely on indirect northern hemisphere for both academic studies of ice sheet history geophysical datasets such as marine seismics and airborne radar. and applied science such as mineral exploration, but has only However, physical samples provide information essential to ice begun to be widely used in Antarctica in the past decade. Early sheet reconstructions, including analysis of sediment provenance work in the Ross Sea by Stetson and Upson (1937), using cores Fig. 1. (A) Locations named in text shown on the BEDMAP 2 subglacial topography from Fretwell et al. (2013) with a semi-transparent overlay of the Landsat Image Mosaic created with GeoMapApp. Red lines show ice divides, black dashed lines are ice streams, blue arrow show generalized surface currents. AL ¼ Adelie Land, BG¼Byrd Glacier, DV ¼ Dry Valleys, EM ¼ Ellsworth Mountains, GVL ¼ George V Land, MA ¼ Mt. Achernar and Law Glacier, NG¼Nimrod Glacier, NVL ¼ north Victoria Land, R-F ¼ Ronne-Filchner, and RG ¼ Reedy Glacier, SCIS¼Siple Coast ice streams, yellow dot marks Skelton-Mulock Glaciers. (B) Model reconstruction of Antarctic ice flow lines for the Last Glacial Maximum (Golledge et al., 2013) compared to modern grounded ice extent shown on base image (grey shading). K.J. Licht, S.R. Hemming / Quaternary Science Reviews 164 (2017) 1e24 3 collected during the second Byrd Antarctic Expedition, appears to single provenance method is applied. This concept is summarized be the first to analyze till composition and infer its provenance. with simplistic scenarios (Fig. 2) showing how pairing petrographic Their sand petrographic analysis showed spatial variation across and geochronologic analysis may allow differentiating geologic the Ross Sea, which they speculated meant there were different terranes. Finally, we have selected examples that show how prov- source terranes upstream. Since that time, efforts have broadened enance analysis of Antarctic glacigenic sediments has advanced our to include a source-to-sink approach that evaluates the provenance knowledge of Antarctica's glacial and geologic history from the of terrestrial tills from inland nunataks and follows their contri- continent to the catchment scale and across a broad range of butions to offshore deposits (Licht and Palmer, 2013). We have temporal scales. learned through this strategy that it is possible to obtain sediment eroded from the entirely ice-covered continental interior by col- 2. Background lecting till at the most upstream limits of outlet glaciers before ice crosses through and incorporates sediment eroded from the 2.1. What is the geology of Antarctica that makes this possible? Transantarctic Mountains (Palmer et al., 2012). A diverse suite of provenance tools and multi proxy approaches, ranging from Many of the topics typically addressed with glacigenic sediment traditional sand petrography to isotopic and geochronological provenance studies, such as ice flowline reconstructions and origin methods, have been applied to Antarctic provenance questions and of ice-rafted detritus (IRD), require that the bedrock types and ages will be discussed in the paper. have some spatial variability. The scale of that variability and the Glacigenic sediments provide a broader array of sediment processes by which sediment is eroded and transported affect what provenance analysis opportunities than any other sediment type provenance signatures are resolvable in the geologic record. because of the wide range of grain sizes that characterize them. The Antarctica poses a special challenge because so little bedrock of the provenance tools that have been well tested for sandstones, continent is exposed and the catchment areas for outlet glaciers can mudrocks and conglomerates can be applied in combination to be more than 106 km2. Whereas both the source terranes and gla- glacigenic sediments. The challenge (and opportunity)
Load more

Recommended publications
  • Lost Cold Antarctic Deserts Inferred from Unusual Sulfate Formation and Isotope Signatures
    ARTICLE Received 15 Oct 2014 | Accepted 20 May 2015 | Published 29 Jun 2015 DOI: 10.1038/ncomms8579 Lost cold Antarctic deserts inferred from unusual sulfate formation and isotope signatures Tao Sun1,2,w, Richard A. Socki3,w, David L. Bish4, Ralph P. Harvey5, Huiming Bao1, Paul B. Niles2, Ricardo Cavicchioli6 & Eric Tonui7 The Antarctic ice cap significantly affects global ocean circulation and climate. Continental glaciogenic sedimentary deposits provide direct physical evidence of the glacial history of the Antarctic interior, but these data are sparse. Here we investigate a new indicator of ice sheet evolution: sulfates within the glaciogenic deposits from the Lewis Cliff Ice Tongue of the central Transantarctic Mountains. The sulfates exhibit unique isotope signatures, including d34Supto þ 50% for mirabilite evaporites, D17Oupto þ 2.3% for dissolved sulfate within contemporary melt-water ponds, and extremely negative d18Oaslowas À 22.2%. The isotopic data imply that the sulfates formed under environmental conditions similar to today’s McMurdo Dry Valleys, suggesting that ice-free cold deserts may have existed between the South Pole and the Transantarctic Mountains since the Miocene during periods when the ice sheet size was smaller than today, but with an overall similar to modern global hydrological cycle. 1 Louisiana State University, Baton Rouge, Louisiana 70803, USA. 2 NASA Johnson Space Center, Houston, Texas 77058, USA. 3 ESCG, NASA Johnson Space Center, Houston, Texas 77058, USA. 4 Indiana University, Bloomington, Indianapolis 47405, USA. 5 Case Western Reserve University, Cleveland, Ohio 44106, USA. 6 University of New South Wales, Sydney, New South Wales 2052, Australia. 7 Upstream Technology, BP America, Houston, Texas 77079, USA.
    [Show full text]
  • The Undiscovered Oil and Gas of Antarctica
    DEPARTMENT OF THE INTERIOR U.S. Geological Survey The Undiscovered Oil and Gas of Antarctica by John Kingston^ OPEN-FILE REPORT 91-597 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ^Santa Barbara, California CONTENTS Page Abstract ....................................................... 1 Introduction ................................................... 2 Size of area .............................................. 2 Premise and problems of petroleum recoverability .......... 2 Previous investigations and petroleum assessments ......... 2 Methods of assessment ..................................... 4 Regional geology and petroleum occurrence ...................... 6 Assessment by play analysis .................................... 13 Rifted continental margin provinces ....................... 13 General; the south Australia rifted margin analog .... 13 Antarctica-Australia rift province ................... 17 Antarctica-India rift province ....................... 20 Antarctica-Africa rift province ...................... 24 Antarctica-Falkland rift province .................... 24 Interior rift provinces ................................... 30 General .............................................. 30 Ross sea interior rift province ...................... 30 Weddell sea interior rift province ..................
    [Show full text]
  • Stratigraphy of Upper Carboniferous and Permian Rocks Exposed Between the Byrd and Nimrod Glaciers JOHN L
    Boulder, here. The project was supported by National Science Founda- belts along the Panthalassan margin of Gondwanaland. Colorado: Geological Society of America. tion grants OPP 89-17348 and OPP 89-15429. Elliot, D.H. 1992. Jurassic magmatism and tectonism associated with Gondwanaland break-up: An antarctic perspective. In B.C. Alabaster and R.J. Pankhurst (Eds.), Magmatism and the causes of References continental break-up (Special Publication No. 68). London: Geo- logical Society of London. Barrett, P.J., D.H. Elliot, and J.F. Lindsay. 1986. The Beacon Super- Elliot, D.H., and D. Larsen. 1993. Mesozoic volcanism in the central group (Devonian-Triassic) and Ferrar Group (Jurassic) in the Transantarctic Mountains, Antarctica: Depositional environment Beardmore Glacier area, Antarctica. In M.D. Turner and J.F. and tectonic setting. In R.H. Findlay, R. Unrug, M.R. Banks, and J.J. Gondwana Eight: Assembly, evolution and Splettstoesser (Eds.), Geology of the central Transantarctic Moun- Veevers, (Eds.), tains (Antarctic Research Series, Vol. 36). Washington, D.C.: Ameri- dispersal. Rotterdam: Balkema. can Geophysical Union. Larsen, D. 1988. The petrology and geochemistry of the volcaniclastic Collinson, J.W., J.L. Isbell, D.H. Elliot, M.F. Miller, and J.W.G. Miller. In upper part of the Falla Formation and Prebble Formation, Beard- press. Permian-Triassic Transantarctic basin. In J.J. Veevers and C. more Glacier area, Antarctica. (Unpublished master of science the- McA. Powell (Eds.), Permian-Triassic Pangaean basins and fold- sis, Ohio State University, Columbus, Ohio.) Stratigraphy of Upper Carboniferous and Permian rocks exposed between the Byrd and Nimrod Glaciers JOHN L.
    [Show full text]
  • SUN-DISSERTATION-2019.Pdf (5.590Mb)
    © Copyright by Zhiyue Sun, 2019 All Rights Reserved ESTIMATING GLACIER ICE THICKNESS AND MASS BALANCE USING MULTIPLE SPACEBORNE GEODETIC TECHNIQUES A Dissertation Presented to the Faculty of the Department of Civil and Environmental Engineering University of Houston In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in Geosensing Systems Engineering and Sciences by Zhiyue Sun May 2019 ESTIMATING GLACIER ICE THICKNESS AND MASS BALANCE USING MULTIPLE SPACEBORNE GEODETIC TECHNIQUES __________________________ Zhiyue Sun Approved: ________________________________ Chair of the Committee Hyongki Lee, Ph.D. Associate Professor Civil & Environmental Engineering Committee Members: ________________________________ Ramesh L. Shrestha, Ph.D. Hugh Roy & Lillie Cranz Cullen Distinguished Professor Civil & Environmental Engineering ________________________________ Craig L. Glennie, Ph.D. Associate Professor Civil & Environmental Engineering ________________________________ Yushin. Ahn, Ph.D. Assistant Professor Geomatics Engineering California State University, Fresno, CA ________________________________ Alexander. Braun, Ph.D. Professor Geological Sciences and Geological Engineering Queen’s University, Kingston, Canada ________________________________ ________________________________ Suresh K. Khator, Ph.D. Craig L. Glennie, Ph.D. Associate Dean Geosensing Systems Engineering & Cullen College of Engineering Science Program Director ESTIMATING GLACIER ICE THICKNESS AND MASS BALANCE USING MULTIPLE SPACEBORNE GEODETIC TECHNIQUES
    [Show full text]
  • Formation and Evolution of an Extensive Blue Ice Moraine in Central Transantarctic Mountains, Antarctica
    Journal of Glaciology Formation and evolution of an extensive blue ice moraine in central Transantarctic Mountains, Antarctica Paper Christine M. Kassab1 , Kathy J. Licht1, Rickard Petersson2, Katrin Lindbäck3, 1,4 5 Cite this article: Kassab CM, Licht KJ, Joseph A. Graly and Michael R. Kaplan Petersson R, Lindbäck K, Graly JA, Kaplan MR (2020). Formation and evolution of an 1Department of Earth Sciences, Indiana University-Purdue University Indianapolis, 723 W Michigan St, SL118, extensive blue ice moraine in central Indianapolis, IN 46202, USA; 2Department of Earth Sciences, Uppsala University, Geocentrum, Villav. 16, 752 36, Transantarctic Mountains, Antarctica. Journal Uppsala, Sweden; 3Norwegian Polar Institute, Fram Centre, P.O. Box 6606 Langnes, NO-9296, Tromsø, Norway; of Glaciology 66(255), 49–60. https://doi.org/ 4Department of Geography and Environmental Sciences, Northumbria University, Ellison Place, Newcastle upon 10.1017/jog.2019.83 Tyne, NE1 8ST, UK and 5Division of Geochemistry, Lamont-Doherty Earth Observatory, Palisades, New York 10964, Received: 22 April 2019 USA Revised: 14 October 2019 Accepted: 15 October 2019 Abstract First published online: 11 November 2019 Mount Achernar moraine is a terrestrial sediment archive that preserves a record of ice-sheet Key words: dynamics and climate over multiple glacial cycles. Similar records exist in other blue ice moraines Blue ice; ground-penetrating radar; moraine elsewhere on the continent, but an understanding of how these moraines form is limited. We pro- formation pose a model to explain the formation of extensive, coherent blue ice moraine sequences based on Author for correspondence: the integration of ground-penetrating radar (GPR) data with ice velocity and surface exposure Christine M.
    [Show full text]
  • Geological Studies in Western Muhlig-Hofmann Mountains, Central Dronning Maud Land, East Antarctica
    Twenty Second Indian Expedition to Antarctica, Scientific Report, 2008 Ministry of Earth Sciences, Technical Publication No. 20, pp 177-189 Geological Studies in Western Muhlig-Hofmann Mountains, Central Dronning Maud Land, East Antarctica A. Dharwaclkar, R. Asthana, K. Kachroo, L.K. Oberoi and Aran Chaturvedi Geological Survey of India INTRODUCTION In pursuance of its long term program of mapping the entire Wohlthat ranges in cDML, East Antarctica, geological mapping was carried out in the western parts of Muhlig-Hofmann Mountains during the 22nd Indian Antarctic Expedition. About 1000 sq km area bounded by Longitudes 5°00' and 5°45' East and Latitudes 71°45' and 72° 10' South was covered during the austral summer of 2002-03. The study area lies more than 170NM WSW of Maitri station and the fieldwork was carried out using helicopters by taking drop- points in the area. GEOLOGICAL SETTING The East Antarctic shield is mostly composed of Precambrian crystalline rocks and has undergone a complex tectono-metamorphic history (Ravich & Kamenev, 1975; Sengupta, 1988; Tingey, 1991; D'Souza et al., 1997). The cDML basically consists of polymetamorphosed metasedimentary rocks represented by garnet-biotite schists, hornblende gneisses, metapelites, calc- silicates etc. These are intruded by various inagmatic units like anorthosite, granodiorite, granite, monzonite, charnockite and other minor instrusives. The deformational record of the region indicates a granulite facies metamorphism (Grenvillian) superimposed by later Pan-African (amphibolite to granulite) event. Record of the earlier Grenvillian event is preserved in the pelitic/ semipelitic schists and mafic granulites. (Jacobs et al., 2003). The Muhlig-Hofmann Mountains occurring in the western part of cDML are dominated by magmatic phase with large plutons of charnockite, granite and syenite forming the intrusive phase.
    [Show full text]
  • Mesozoic and Cenozoic Structural Patterns in the Transantarctic
    and J . Berg for providing powders of xenoliths from the 0 kilometers 300 McMurdo Volcanic Province and unpublished data for these samples. I Victoria Land 0 miles 200 Mc rdo Station 0 GlIB? --BGB Byrd Glacier h East Antarctic Ice Sheet + 80.S RB Ross Ice Shelf Byrd Glacier1 -7 MRB BGB References Nimrod Glacier Berg, J.H., R.A. Hank, and R.I. Kalamarides. 1985. Petrology and Marsh Glacier geochemistry of lower crustal basic granulites from the Erebus Vol- canic Province, Antarctica. 1985. Antarctic Journal of the U.S., 20(5), 22-23. Beardmore Shackleton Glacier Glacier Borg, S.C., and D.J. DePaolo. 1990. Isotopic imaging of deep conti- nental lithosphere. Systematics and applications downunder (ab- stract). 7th International Conference on Geochronology, Cosmochronology, and Isotope Geology, Canberra, Australia, Sep- IAntarcScaS Outcrop area: tember 1990. (Abstracts, Vol. 27.) Canberra: Geological Society of ______________ outh Pole Transantarctic ___________________ + Mountains Australia. Borg, S.C., and D.J. DePaolo. In press. A tectonic model of the Ant- arctic Gondwana margin with implications for southeastern Aus- Figure 3. This map of the Transantarctic Mountains in the vicinity tralia: Isotopic and geochemical evidence. Tectonopliysics. of the Ross Ice Shelf shows our working hypothesis for the dis- Borg, S.C., D.J. DePaolo, E.D. Wendlandt, and T.G. Drake. 1989. tribution of lower crustal provinces. This interpretation is based Studies of granites and metamorphic rocks, Byrd Glacier area. Ant- on the inferences from the isotopic compositions shown in figure arctic Journal of the U.S., 25(5), 19-21. 2 and on our inference from field work that the entire north side of Borg, S.C., D.J.
    [Show full text]
  • 4: Potential Mineral Resources in Antarctica
    Chapter 4 Potential Mineral Resources in Antarctica Photo credit: U.S. Geological Survey Byrd Glacier CONTENTS Page SUMMARY . 93 INTRODUCTION . 93 GEOLOGICAL ASSOCIATIONS . 96 Relationship to Adjacent Continents . 99 Offshore Shelf Areas . 102 ANTARCTICA IN THE CONTEXT OF FUTURE MINERALS SUPPLY . 103 Prospecting and Exploration in Antarctica . 105 Probabilities of Discovering Antarctic Mineral Deposits . 110 SELECTED MINERAL RESOURCES ● . 111 Oil and Gas . .. 111 coal . .114 Uranium . 114 Chromium . .115 Copper . 116 Gold . 117 Iron . .118 Molybdenum . .119 Platinum-Group Metals . .119 Rare-Earth Metals . .120 Diamonds . .. 122 Boxes Box Page 4-A. Mineral Resources and Reserves . 95 4-B. Geologic Time Scale . 98 4-C. Icebergs . 121 Figures Figure Page 4-1. Antarctic Mineral Occurrences . 97 4-2. Geologic Provinces of Antarctica and Their Relationship to Adjacent Gondwana Continents . 100 4-3. Reconstruction of Gondwana in Early Cretaceus Time . 103 4-4. Exposed Rock Outcrop in Antarctica . .. 106 4-5. What Antarctica Would Look Like If the Ice Were Removed . 107 4-6. Multichannel Seismic Data . .. 108 4-7. Sedimentary Basins in Antarctica . ,.. , 112 Tables Table Page 4-1. Desirable Research for Evaluating Resource Potential of Antarctica . 110 4-2. Research Required To Ensure That Petroleum Resources Are Safely and Efficiently Recovered With Minimum Environmental Impact . 110 4-3. Estimated Number of Major Mineral Deposits in Antarctica . 112 Chapter 4 Potential Mineral Resources in Antarctica SUMMARY The offshore sedimentary basins surrounding Antarctica offer the best prospects for petroleum Scientists have discovered occurrences (small exploration. The Weddell and Ross embayments in amounts) of several minerals in Antarctica, but West Antarctica, and Prydz Bay and the Wilkes there are no known mineral deposits of commer- Basin in East Antarctica are among the basins most cial interest.
    [Show full text]
  • 1 Compiled by Mike Wing New Zealand Antarctic Society (Inc
    ANTARCTIC 1 Compiled by Mike Wing US bulldozer, 1: 202, 340, 12: 54, New Zealand Antarctic Society (Inc) ACECRC, see Antarctic Climate & Ecosystems Cooperation Research Centre Volume 1-26: June 2009 Acevedo, Capitan. A.O. 4: 36, Ackerman, Piers, 21: 16, Vessel names are shown viz: “Aconcagua” Ackroyd, Lieut. F: 1: 307, All book reviews are shown under ‘Book Reviews’ Ackroyd-Kelly, J. W., 10: 279, All Universities are shown under ‘Universities’ “Aconcagua”, 1: 261 Aircraft types appear under Aircraft. Acta Palaeontolegica Polonica, 25: 64, Obituaries & Tributes are shown under 'Obituaries', ACZP, see Antarctic Convergence Zone Project see also individual names. Adam, Dieter, 13: 6, 287, Adam, Dr James, 1: 227, 241, 280, Vol 20 page numbers 27-36 are shared by both Adams, Chris, 11: 198, 274, 12: 331, 396, double issues 1&2 and 3&4. Those in double issue Adams, Dieter, 12: 294, 3&4 are marked accordingly. Adams, Ian, 1: 71, 99, 167, 229, 263, 330, 2: 23, Adams, J.B., 26: 22, Adams, Lt. R.D., 2: 127, 159, 208, Adams, Sir Jameson Obituary, 3: 76, A Adams Cape, 1: 248, Adams Glacier, 2: 425, Adams Island, 4: 201, 302, “101 In Sung”, f/v, 21: 36, Adamson, R.G. 3: 474-45, 4: 6, 62, 116, 166, 224, ‘A’ Hut restorations, 12: 175, 220, 25: 16, 277, Aaron, Edwin, 11: 55, Adare, Cape - see Hallett Station Abbiss, Jane, 20: 8, Addison, Vicki, 24: 33, Aboa Station, (Finland) 12: 227, 13: 114, Adelaide Island (Base T), see Bases F.I.D.S. Abbott, Dr N.D.
    [Show full text]
  • Geology of Antarctica
    GEOLOGY OF ANTARCTICA 1. Global context of Antarctica Compared with other continents, the geological evolution of Antarctica is relatively little known, since less than 2% of the land emerges from beneath the thick cover of glacier ice. Yet where rocks are exposed, their pristine nature and lack of vegetation has enabled geologists to unravel many key components of the region’s history. In addition, the use of geophysical and remote sensing techniques, together with drilling on the Continental Shelf, has helped resolve many of the geological questions posed by the limited outcrop. Antarctica is the remotest of the world’s continents, with its nearest neighbour being South America, some 100 km (560 miles) distant. Yet, relatively early on in the geological exploration of Antarctica it was recognized that Antarctica shared a common history with other southern hemisphere continents, such as South America, Africa, Arabia, India and Australasia. However, these early ideas of movement of continents by joining together, followed by splitting apart, were ridiculed by many geologists and geophysicists, until the revolution in geological thinking in the late 1960s that led to the ‘theory of plate tectonics’. This collection of photographs is assembled to capture the spirit of Antarctica’s geological evolution, grouped according to the key events that have shaped the continent. A limited knowledge of geological processes and terms is required to fully appreciate this set. Conditions of use of images 1 Contributors (who retain copyright), to whom requests for reproduction should be sent, are listed after the caption by their initials. In general, reproduction of these relatively low-resolution images is permitted for educational purposes without prior permission, e.g.
    [Show full text]
  • Antarctic Surface Hydrology and Impacts on Ice-Sheet Mass Balance
    PERSPECTIVE https://doi.org/10.1038/s41558-018-0326-3 Antarctic surface hydrology and impacts on ice-sheet mass balance Robin E. Bell 1*, Alison F. Banwell 2,3, Luke D. Trusel 4 and Jonathan Kingslake 1,5 Melting is pervasive along the ice surrounding Antarctica. On the surface of the grounded ice sheet and floating ice shelves, extensive networks of lakes, streams and rivers both store and transport water. As melting increases with a warming climate, the surface hydrology of Antarctica in some regions could resemble Greenland’s present-day ablation and percolation zones. Drawing on observations of widespread surface water in Antarctica and decades of study in Greenland, we consider three modes by which meltwater could impact Antarctic mass balance: increased runoff, meltwater injection to the bed and meltwa- ter-induced ice-shelf fracture — all of which may contribute to future ice-sheet mass loss from Antarctica. urface meltwater in Antarctica is more extensive than previ- Through-ice fractures are interpreted as evidence of water having ously thought and its role in projections of future mass loss drained through ice shelves (Figs 1a and 2)15. Similar to terrestrial Sare becoming increasingly important. As accurately projecting hydrologic systems, these components of the Antarctic hydrologic future sea-level rise is essential for coastal communities around the system store, transport and export water. In contrast to terrestrial globe, understanding how surface melt may either trigger or buf- hydrology, on ice sheets and glaciers water can refreeze with conse- fer rapid changes in ice flow into the ocean is critical. We provide quences for the temperature of the surrounding ice16–18, firn or snow.
    [Show full text]
  • Mm^Umamm a N E W S B U L L E T I N
    mm^umamm A N E W S B U L L E T I N p u b l i s h e d q u a r t e r l y b y t h e NEW ZEALAND ANTARCTIC SOCIETY ■ H.M.N.Z.S. ENDEAVOUR about to tie up in Winter Quarters Bay. On right, Vince's Cross and Scott's hut. J. Calvert photo. MARCH, 1965 AUSTRALIA Winter and Summer bases Scott- S u m m e r b a s e o n l y t H a l l e f t "cton NEW ZEALAND Transferred base Wilkes UStcAust Temporarily non -operational. .KSyowa TASMANIA , Campbell I. (N-l) , ^ V - r . ^ ^ N . AT // \$ 5«|* Pasar'C ^rd(i/.sA . *"Vp»tuk , N |(I/.«.AJ i - S c o t t ( U . 5 J i t - A N T A R. M^ciJ ^>cwj a fi/V wX " < S M a u d **$P -Marion I. ttM DRAWN BY DEPARTMENT OF LANDS 1 SURVEY WELLINGTON, NEW ZEALAND, MAR.I9l»4- 1 " . " E D I T I O N m ilHl^IBS^IKB^k (Successor to "Antarctic News Bulletin") MARCH, 1965 Editor: L. B. Quartermain, M.A., 1 Ariki Road, Wellington, E.2, New Zealand. Business Communications, Subscriptions, etc., to: Secretary, New Zealand Antarctic Society, P.O. Box 2110, Wellington, N.Z. CONTENTS EXPEDITIONS New Zealand The Central Nimrod Glacier Geological Expedition: M. G. Laird Victoria University Research in Ice-free Areas: W. M. Prebble The D-region Project: J. B. Gregory France United States First Leg of Traverse Australia Belgium-Holland U.S.S.R South Africa Argentina United Kingdom Chile Japan Sub-Antarctic Islands British South Georgia Expedition Big Ben Conquered Special Articles: Hallett Closed Antarctic Stations—I.
    [Show full text]