Author
Matt A. King
Other affiliations: Hobart Corporation, National Chemical Laboratory, Newcastle University ...read more
Bio: Matt A. King is an academic researcher from University of Tasmania. The author has contributed to research in topics: Ice sheet & Ice stream. The author has an hindex of 54, co-authored 146 publications receiving 10602 citations. Previous affiliations of Matt A. King include Hobart Corporation & National Chemical Laboratory.
Papers published on a yearly basis
Papers
More filters
University of Leeds1, Jet Propulsion Laboratory2, University of Colorado Boulder3, Technical University of Denmark4, Durham University5, University of Texas at Austin6, Ohio State University7, University College London8, Technische Universität München9, Lamont–Doherty Earth Observatory10, Johns Hopkins University Applied Physics Laboratory11, Newcastle University12, University of Tasmania13, Utrecht University14, University of Kansas15, Swansea University16, Goddard Space Flight Center17, University of Ottawa18, University of California, Irvine19, University of Bristol20, British Antarctic Survey21, University of Innsbruck22, Delft University of Technology23
TL;DR: There is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty, and the mass balance of Earth’s polar ice sheets is estimated by combining the results of existing independent techniques.
Abstract: We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.
1,215 citations
01 Jan 2012
1,155 citations
TL;DR: The rapid (<2 hours) drainage of a large supraglacial lake down 980 meters through to the bed of the Greenland Ice Sheet initiated by water-driven fracture propagation evolving into moulin flow coincided with increased seismicity, transient acceleration, ice-sheet uplift, and horizontal displacement.
Abstract: Surface meltwater that reaches the base of an ice sheet creates a mechanism for the rapid response of ice flow to climate change. The process whereby such a pathway is created through thick, cold ice has not, however, been previously observed. We describe the rapid (<2 hours) drainage of a large supraglacial lake down 980 meters through to the bed of the Greenland Ice Sheet initiated by water-driven fracture propagation evolving into moulin flow. Drainage coincided with increased seismicity, transient acceleration, ice-sheet uplift, and horizontal displacement. Subsidence and deceleration occurred over the subsequent 24 hours. The short-lived dynamic response suggests that an efficient drainage system dispersed the meltwater subglacially. The integrated effect of multiple lake drainages could explain the observed net regional summer ice speedup.
552 citations
TL;DR: A data set is assembled that provides a synoptic-scale view, spanning ice-sheet to outlet-glacier flow, that reveals summer speedups on the ice sheet consistent with, but somewhat larger than, earlier observations.
Abstract: It has been widely hypothesized that a warmer climate in Greenland would increase the volume of lubricating surface meltwater reaching the ice-bedrock interface, accelerating ice flow and increasing mass loss. We have assembled a data set that provides a synoptic-scale view, spanning ice-sheet to outlet-glacier flow, with which to evaluate this hypothesis. On the ice sheet, these data reveal summer speedups (50 to 100%) consistent with, but somewhat larger than, earlier observations. The relative speedup of outlet glaciers, however, is far smaller (<15%). Furthermore, the dominant seasonal influence on Jakobshavn Isbrae's flow is the calving front's annual advance and retreat. With other effects producing outlet-glacier speedups an order of magnitude larger, seasonal melt's influence on ice flow is likely confined to those regions dominated by ice-sheet flow.
437 citations
TL;DR: In this article, the authors used GPS data collected along a ∼35 km transect at the western margin of the Greenland ice sheet throughout a summer melt season to study the response of ice motion to seasonal variations in meltwater supply.
Abstract: An acceleration of ice-mass loss has been observed near the margin of the Greenland ice sheet, partly as a result of faster ice motion. Observations by GPS receivers reveal high seasonal variability in ice motion, with summer motion up to 220% higher than winter background levels. The Greenland ice sheet contains enough water to raise sea levels by 7 m. However, its present mass balance and future contribution to sea level rise is poorly understood1. Accelerated mass loss has been observed near the ice sheet margin, partly as a result of faster ice motion2,3,4. Surface melt waters can reach the base of the ice sheet and enhance basal ice motion5,6. However, the response of ice motion to seasonal variations in meltwater supply is poorly constrained both in space and time. Here we present ice motion data obtained with global positioning system receivers located along a ∼35 km transect at the western margin of the Greenland ice sheet throughout a summer melt season. Our measurements reveal substantial increases in ice velocity during summer, up to 220% above winter background values. These speed-up events migrate up the glacier over the course of the summer. The relationship between melt and ice motion varies both at each site throughout the melt season and between sites. We suggest that these patterns can be explained by the seasonal evolution of the subglacial drainage system similar to hydraulic forcing mechanisms for ice dynamics that have been observed at smaller glaciers.
360 citations
Cited by
More filters
Australian National University1, Stockholm Resilience Centre2, University of Copenhagen3, McGill University4, Stellenbosch University5, University of Wisconsin-Madison6, Wageningen University and Research Centre7, Stockholm University8, Royal Swedish Academy of Sciences9, Potsdam Institute for Climate Impact Research10, Commonwealth Scientific and Industrial Research Organisation11, International Livestock Research Institute12, University College London13, Stockholm Environment Institute14, The Energy and Resources Institute15, University of California, San Diego16, Royal Institute of Technology17
TL;DR: An updated and extended analysis of the planetary boundary (PB) framework and identifies levels of anthropogenic perturbations below which the risk of destabilization of the Earth system (ES) is likely to remain low—a “safe operating space” for global societal development.
Abstract: The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth system into a new state should they be substantially and persistently transgressed.
7,169 citations
TL;DR: The climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop, showing that thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise.
Abstract: The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.
2,604 citations
South Dakota State University1, Natural Resources Canada2, United States Geological Survey3, Boston University4, University of Idaho5, United States Department of Agriculture6, Goddard Space Flight Center7, University of Colorado Boulder8, University of Massachusetts Boston9, Rochester Institute of Technology10, University of California, Los Angeles11, United States Forest Service12, Agricultural Research Service13, Humboldt University of Berlin14, Desert Research Institute15, University of Maryland, College Park16, University of Nebraska–Lincoln17, Geoscience Australia18, Virginia Tech19
TL;DR: Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared as mentioned in this paper.
1,697 citations
University of Leeds1, Jet Propulsion Laboratory2, University of Colorado Boulder3, Technical University of Denmark4, Durham University5, University of Texas at Austin6, Ohio State University7, University College London8, Technische Universität München9, Lamont–Doherty Earth Observatory10, Johns Hopkins University Applied Physics Laboratory11, Newcastle University12, University of Tasmania13, Utrecht University14, University of Kansas15, Swansea University16, Goddard Space Flight Center17, University of Ottawa18, University of California, Irvine19, University of Bristol20, British Antarctic Survey21, University of Innsbruck22, Delft University of Technology23
TL;DR: There is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty, and the mass balance of Earth’s polar ice sheets is estimated by combining the results of existing independent techniques.
Abstract: We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.
1,215 citations
01 Jan 2012
1,155 citations