Author
Martin J. Siegert
Other affiliations: University of Edinburgh, University of Wales, Aberystwyth University ...read more
Bio: Martin J. Siegert is an academic researcher from Imperial College London. The author has contributed to research in topics: Ice sheet & Ice stream. The author has an hindex of 58, co-authored 293 publications receiving 14404 citations. Previous affiliations of Martin J. Siegert include University of Edinburgh & University of Wales.
Topics: Ice sheet, Ice stream, Antarctic ice sheet, Ice shelf, Sea ice
Papers published on a yearly basis
Papers
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British Antarctic Survey1, University of Bristol2, Columbia University3, National Institute of Geophysics and Volcanology4, University of Aberdeen5, University of Texas at Austin6, Centro de Estudios Científicos7, Université libre de Bruxelles8, University of Washington9, Swansea University10, Institute for Geosciences and Natural Resources11, Technical University of Denmark12, National Institute of Polar Research13, California Institute of Technology14, University of Kansas15, Stockholm University16, St. Olaf College17, Norwegian Polar Institute18, Wallops Flight Facility19, University of Canterbury20, University of Oslo21, University of California, Santa Barbara22, University of California, Irvine23, University of York24, Australian Antarctic Division25, Newcastle University26, Goddard Space Flight Center27, Polar Research Institute of China28
TL;DR: Bedmap2 as discussed by the authors is a suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1.
Abstract: We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data-coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6% greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10%. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.
1,678 citations
Bjerknes Centre for Climate Research1, Stockholm University2, Saint Petersburg State University3, Russian Academy of Sciences4, University of Cambridge5, Geological Museum6, Gas Technology Institute7, Lund University8, University of Copenhagen9, Alfred Wegener Institute for Polar and Marine Research10, University of Iceland11, University of New Hampshire12, Geological Survey of Sweden13, University of Oulu14, Aarhus University15, Ohio State University16, Geological Survey of Finland17, University of Bristol18, Leibniz Association19
TL;DR: In this paper, the maximum limits of the Eurasian ice sheets during four glaciations have been reconstructed: (1) the Late Saalian (>140 ka), (2) the Early Weichselian (100-80 ka),(3) the Middle Weichsellian (60-50 ka), and (4) the late Weichselsian (25-15 ka) based on satellite data and aerial photographs combined with geological field investigations in Russia and Siberia, and with marine seismic and sediment core data.
1,426 citations
University of California, Irvine1, British Geological Survey2, University of Bristol3, California Institute of Technology4, Alfred Wegener Institute for Polar and Marine Research5, University of Texas at Austin6, Aberystwyth University7, Scott Polar Research Institute8, Natural Environment Research Council9, Ohio State University10, Stockholm University11, Technical University of Denmark12, University of Ottawa13, University of Copenhagen14, University of New Hampshire15, Utrecht University16, Durham University17, University of Exeter18, Aarhus University19, University of Manitoba20, Imperial College London21, Woods Hole Oceanographic Institution22
TL;DR: A new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach is presented, yielding major improvements over previous data sets, particularly in the marine‐terminating sectors of northwest and southeast Greenland.
Abstract: Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.
535 citations
TL;DR: This paper reviewed the geological observations and interpretations regarding the size and timing of the Late Weichselian Barents ice sheet, combined with numerical modelling of its formation in order to produce a reconstruction of ice sheet extent and behaviour.
390 citations
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01 Jan 2013
TL;DR: The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial-interglacial cycles.
Abstract: The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial–interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Interglacial periods differed in temporal evolution and duration. Atmospheric concentrations of carbon dioxide and methane correlate well with Antarctic air-temperature throughout the record. Present-day atmospheric burdens of these two important greenhouse gases seem to have been unprecedented during the past 420,000 years.
5,469 citations
TL;DR: The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial-interglacial cycles as discussed by the authors.
Abstract: The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial–interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Interglacial periods differed in temporal evolution and duration. Atmospheric concentrations of carbon dioxide and methane correlate well with Antarctic air-temperature throughout the record. Present-day atmospheric burdens of these two important greenhouse gases seem to have been unprecedented during the past 420,000 years.
5,109 citations
Journal Article•
TL;DR: Prospect Theory led cognitive psychology in a new direction that began to uncover other human biases in thinking that are probably not learned but are part of the authors' brain’s wiring.
Abstract: In 1974 an article appeared in Science magazine with the dry-sounding title “Judgment Under Uncertainty: Heuristics and Biases” by a pair of psychologists who were not well known outside their discipline of decision theory. In it Amos Tversky and Daniel Kahneman introduced the world to Prospect Theory, which mapped out how humans actually behave when faced with decisions about gains and losses, in contrast to how economists assumed that people behave. Prospect Theory turned Economics on its head by demonstrating through a series of ingenious experiments that people are much more concerned with losses than they are with gains, and that framing a choice from one perspective or the other will result in decisions that are exactly the opposite of each other, even if the outcomes are monetarily the same. Prospect Theory led cognitive psychology in a new direction that began to uncover other human biases in thinking that are probably not learned but are part of our brain’s wiring.
4,351 citations
Journal Article•
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.
4,187 citations
Academy of Sciences of the Czech Republic1, Charles University in Prague2, University of Bergen3, University of Nottingham4, Boise State University5, Goethe University Frankfurt6, Memorial University of Newfoundland7, Stockholm University8, University of Vienna9, University of Geneva10, Swedish Museum of Natural History11
TL;DR: The Plesovice zircon as discussed by the authors has a concordant U-Pb age with a weighted mean Pb-206/U-238 date of 337.13 +/- 0.37 Ma (ID-TIMS, 95% confidence limits, including tracer calibration uncertainty).
3,694 citations