Download or read book When How and why Did the West Antarctic Ice Sheet Retreat in the Ross Sea Since the Last Glacial Maximum Using Foraminiferal and Porewater Geochemistry written by Matthew DeCesare and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth and Retreat of the West Antarctic Ice Sheet from the Last Glacial Maximum to the Present in the Eastern Ross Sea Antarctica written by Amanda Beth Mosola and published by . This book was released on 2004 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine geological evidence supports rapid retreat of the West Antarctic Ice Sheet in the eastern Ross Sea before the last glacial maximum. As the only accessible marine record of a major drainage outlet of the West Antarctic Ice Sheet (WAIS), this central and eastern Ross Sea dataset provides a unique opportunity to test the hypothesis of WAIS instability, assess its regulating role in eustasy, and explore the geological record of paleo-ice stream behavior. As the last vast marine-based ice sheet on the planet, the WAIS is seen as a key source of potentially rapid sea level rise. The collapse and disintegration of the WAIS would raise sea level by 5 to 6 meters, a major threat to the world's coastal cities. Marine geological data were collected along the axis of large bathymetric troughs during a 1999 cruise of the R/V Nathanial B. Palmer. Thick till sheets, extensive lineations, and multiple grounding zone wedges imaged on seismic profiles and multibeam bathymetric records, indicate that troughs in the Ross Sea were occupied by paleo-ice streams during the last glacial maximum. Ice stream boundaries in the eastern Ross Sea are characterized by laterally accreting sedimentary strata indicating lateral migration of ice streams. The abrupt transition from lineated to non-lineated morphologies reflects sharp ice stream margins. Sediment cores recovered glacial-marine deposits overlying till, a facies succession that indicates an abrupt transition from subglacial to open marine deposition. High concentrations of ice rafted debris in the glacial-marine units and iceberg furrows suggest mass wasting of the ice sheet and iceberg calving from the grounding line during retreat. Corrected radiocarbon ages of samples taken above the contact between subglacial (till) and glacial-marine sediments range from 23.4 to 26.0 ka. B.P., indicating pre-LGM ice sheet withdrawal in the eastern Ross Sea. This was long before the ice sheet retreated from the western Ross Sea and is inconsistent with previous models for ice sheet retreat in the region.
Download or read book West Antarctic Ice Sheet Retreat During the Last Interglacial written by Gail Ruth Muldoon and published by . This book was released on 2018 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Last Interglacial (116 ka - 130 ka) is the most recent time when Earth's climate was as warm or warmer than it is today. It therefore may make a suitable proxy for understanding the impacts of modern climate change. One such impact of immediate relevance to the modern world is that of sea level rise. Global sea level is currently rising at an accelerating pace, threatening lives and economies around the world. Notably, evidence from paleoclimate data suggests global sea level during the Last Interglacial was at least 6.6 m higher than present sea level and perhaps more than 8 m higher. As the Earth adjusts to the rapid onset of modern climate change, we may expect sea level to approach that of the Last Interglacial. Noticeable changes in sea level have a number of sources, including melting glaciers, ice sheets, and ocean thermal expansion. The Antarctic Ice Sheet has been inferred to be the largest contributor to Last Interglacial sea level change, adding between 4.1 and 5.8 m to global sea level during that time. Most of this change is expected to come from the West Antarctic Ice Sheet, which is thought to be prone to marine ice sheet instability. However, uncertain basal boundary conditions and ocean forcing make it a challenge to know how the ice sheet may have lost such a large amount of mass. In this work, I seek to better constrain mass balance and sea level contributions of the Antarctic Ice Sheet during the Last Interglacial and explore evidence from inside the ice sheet itself which may reveal if and how the ice sheet sustained such a large mass balance change during the Last Interglacial. To do so, I use a transient ice sheet model to simulate reconfiguration of the Antarctic Ice Sheet under Last Interglacial conditions and find a stable configuration consistent with estimates of Antarctic contributions to Last Interglacial sea level. I then analyze englacial radar stratigraphy to study the ice dynamics by dating a series of isochronous englacial reflectors which have been mapped through the central West Antarctic Ice Sheet. For comparison to this data, I implement a steady state ice sheet model to simulate englacial isochronous surfaces with various uncertain model boundary conditions.
Download or read book West Antarctic Ice Sheet Retreat Chronology of Two Middle shelf Grounding zone Wedges in Eastern Basin Ross Sea Antarctica written by Lenora Nicole Copeland and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Glacial history of the Ross Sea sector of the West Antarctic Ice Sheet written by M.J. SIEGERT and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Pleistocene Holocene retreat of the West Antarctic ice sheet system in the Ross Sea written by S. SHIPP and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Is the West Antarctic Ice Sheet Disintegrating written by T. Hughes and published by . This book was released on 1974 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Pleistocene Holocene retreat of the West Antarctic ice sheet system in the Ross Sea written by E.W. DOMACK and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book What is Happening to the West Antarctic Ice Sheet written by R. A. Bindschadler and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article discusses the history of the West Antarctic ice sheet including the amount of ice that has been lost by the ice sheet since the last glacial maximum 20,000 years ago, whether the sheets fringing ice shelves or its marine base make it inherently unstable, and whether the ice sheet was ever smaller during glacial minimums than it is today. Using evidence from diatoms identified from samples of the bed extracted from underneath 1000 meters of ice, it has been determined that during at least one recent minimum there was no ice at all in the present interior of West Antarctica. A recent reconstruction of the ice sheet in the Ross ice shelf during the last glacial maximum is discussed. The volcanic record suggests that a the West Antarctic ice sheet first appeared approximately 9 million years ago. Mass input to the West Antarctic ice sheet, mass budgets beneath the ice shelves and coupled atmosphere-ocean-ice global circulation models (GCM) are considered. Public education regarding ice sheet issues through the West Antarctic Ice Sheet program is considered.
Download or read book Antarctic Palaeoenvironments and Earth Surface Processes written by M.J. Hambrey and published by Geological Society of London. This book was released on 2013-12-05 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: The volume highlights developments in our understanding of the palaeogeographical, palaeobiological, palaeoclimatic and cryospheric evolution of Antarctica. It focuses on the sedimentary record from the Devonian to the Quaternary Period. It features tectonic evolution and stratigraphy, as well as processes taking place adjacent to, beneath and beyond the ice-sheet margin, including the continental shelf. The contributions in this volume include several invited review papers, as well as original research papers arising from the International Symposium on Antarctic Earth Sciences in Edinburgh, in July 2011. These papers demonstrate a remarkable diversity of Earth science interests in the Antarctic. Following international trends, there is particular emphasis on the Cenozoic Era, reflecting the increasing emphasis on the documentation and understanding of the past record of ice-sheet fluctuations. Furthermore, Antarctic Earth history is providing us with important information about potential future trends, as the impact of global warming is increasingly felt on the continent and its ocean.
Download or read book Glacial Geology written by Matthew M. Bennett and published by John Wiley & Sons. This book was released on 2011-09-20 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new Second Edition of Glacial Geology provides a modern, comprehensive summary of glacial geology and geomorphology. It is has been thoroughly revised and updated from the original First Edition. This book will appeal to all students interested in the landforms and sediments that make up glacial landscapes. The aim of the book is to outline glacial landforms and sediments and to provide the reader with the tools required to interpret glacial landscapes. It describes how glaciers work and how the processes of glacial erosion and deposition which operate within them are recorded in the glacial landscape. The Second Edition is presented in the same clear and concise format as the First Edition, providing detailed explanations that are not cluttered with unnecessary detail. Additions include a new chapter on Glaciations around the Globe, demonstrating the range of glacial environments present on Earth today and a new chapter on Palaeoglaciology, explaining how glacial landforms and sediments are used in ice-sheet reconstructions. Like the original book, text boxes are used throughout to explain key concepts and to introduce students to case study material from the glacial literature. Newly updated sections on Further Reading are also included at the end of each chapter to point the reader towards key references. The book is illustrated throughout with colour photographs and illustrations.
Download or read book Antarctic Glacial Chronology New Constraints from Surface Exposure Dating written by and published by . This book was released on 2000 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface exposure dating using 3He, Ne-21 and Cl-36 combined with mapping of moraines, provide new constraints on West Antarctic Ice Sheet (WAIS) chronology. New He-3 production rates are determined from a 125 ka lava flow. Measurements of inherited He-3/He-4 in two common Antarctic lithologies allow measurement of exposure ages 6000 years. At Mt. Waesche, a moraine band records interior WAIS elevations higher than present. Surface exposure ages indicate that the last ice highstand occurred 10 +/- 1 ka. The data constrain past WAIS behavior and ice volume. Surface exposure ages place age constraints on six Beardmore Glacier drifts. Two drifts record damming of the glacier during the last glacial maximum (10-20 ka) by an expanded WAIS. The four older drifts record similar damming by the WAIS approx. 600 ka, approx. 1 Ma, and approx. 2 Ma. Moraines of Koettlitz Glacier also record damming by the WAIS prior to the LGM. The oldest moraines are 400 ka. Independent stratigraphic control allows evaluation of prior exposure, cover and determination of erosion rates. Taken together, the results are consistent with sea level control of WAIS extent; the WAIS probably has fluctuated synchronously with the Northern Hemisphere ice sheets for at least the last 1 million years.
Download or read book West Antarctic Ice Sheet change since the last glacial period written by R.D. Larter and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Glacier Science and Environmental Change written by Peter G. Knight and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Glacier Science and Environmental Change is an authoritative and comprehensive reference work on contemporary issues in glaciology. It explores the interface between glacier science and environmental change, in the past, present, and future. Written by the world’s foremost authorities in the subject and researchers at the scientific frontier where conventional wisdom of approach comes face to face with unsolved problems, this book provides: state-of-the-art reviews of the key topics in glaciology and related disciplines in environmental change cutting-edge case studies of the latest research an interdisciplinary synthesis of the issues that draw together the research efforts of glaciologists and scientists from other areas such as geologists, hydrologists, and climatologists color-plate section (with selected extra figures provided in color at www.blackwellpublishing.com/knight). The topics in this book have been carefully chosen to reflect current priorities in research, the interdisciplinary nature of the subject, and the developing relationship between glaciology and studies of environmental change. Glacier Science and Environmental Change is essential reading for advanced undergraduates, postgraduate research students, and professional researchers in glaciology, geology, geography, geophysics, climatology, and related disciplines.
Download or read book Antarctic ice sheet and climate history since the Last Glacial Maximum written by M.J. Bentley and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book West Antarctic Ice Sheet written by Robert H. Thomas and published by . This book was released on 1979 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: Retreat of margins associated with rising sea level during last 15,000 years is main cause for thinning by 300 m. During late Wisconsin, ice sheet was 30% wider and Holocene retreat has added 6 m to world sea level.
Download or read book Critical Zones written by Bruno Latour and published by MIT Press. This book was released on 2020-10-13 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Artists and writers portray the disorientation of a world facing climate change. This monumental volume, drawn from a 2020 exhibition at the ZKM Center for Art and Media, portrays the disorientation of life in world facing climate change. It traces this disorientation to the disconnection between two different definitions of the land on which modernizing humans live: the sovereign nation from which they derive their rights, and another one, hidden, from which they gain their wealth—the land they live on, and the land they live from. Charting the land they will inhabit, they find not a globe, not the iconic “blue marble,” but a series of critical zones—patchy, heterogenous, discontinuous. With short pieces, longer essays, and more than 500 illustrations, the contributors explore the new landscape on which it may be possible for humans to land—what it means to be “on Earth,” whether the critical zone, the Gaia, or the terrestrial. They consider geopolitical conflicts and tools redesigned for the new “geopolitics of life forms.” The “thought exhibition” described in this book can opens a fictional space to explore the new climate regime; the rest of the story is unknown. Contributors include Dipesh Chakrabarty, Pierre Charbonnier, Emanuele Coccia, Vinciane Despret, Jerôme Gaillarde, Donna Haraway, Joseph Leo Koerner, Timothy Lenton, Richard Powers, Simon Schaffer, Isabelle Stengers, Bronislaw Szerszynski, Jan A. Zalasiewicz, Siegfried Zielinski Copublished with ZKM | Center for Art and Media Karlsruhe
