A model of Greenland ice sheet deglaciation constrained by observations of relative sea level and ice extent
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Philippe Huybrechts | Lev Tarasov | Antony J. Long | A. Dyke | L. Tarasov | G. Milne | A. Long | P. Huybrechts | N. K. Larsen | K. Kjeldsen | S. Funder | Glenn A. Milne | S. Woodroffe | Arthur S. Dyke | B. Lecavalier | Svend Funder | Kristian K. Kjeldsen | L. Wake | Nicolaj K. Larsen | Benoit S. Lecavalier | Matthew J. R. Simpson | Leanne Wake | Sarah A. Woodroffe | M. Simpson
[1] O. Bennike,et al. Deglaciation chronology, sea-level changes and environmental changes from Holocene lake sediments of Germania Havn Sø, Sabine Ø, northeast Greenland , 2012, Quaternary Research.
[2] J. Andrews,et al. Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records , 2009 .
[3] Shfaqat Abbas Khan,et al. Geodetic measurements of postglacial adjustments in Greenland , 2008 .
[4] Gary D. Clow,et al. Temperature, accumulation, and ice sheet elevation in central Greenland through the last deglacial transition , 1997 .
[5] A. Dyke,et al. Revised estimates of Greenland ice sheet thinning histories based on ice-core records , 2013 .
[6] N. Nørgaard-Pedersen,et al. Neoglacial and historical glacier changes around Kangersuneq fjord in southern West Greenland , 2012 .
[7] Philippe Huybrechts,et al. Sea-level changes at the LGM from ice-dynamic reconstructions of the Greenland and Antarctic ice sheets during the glacial cycles , 2002 .
[8] H. Grobe,et al. Late Quaternary glacial-interglacial changes in sediment composition at the East Greenland continental margin and their paleoceanographic implications , 1995 .
[9] Anker Weidick,et al. Quaternary glaciation history and glaciology of Jakobshavn Isbrae and the Disko Bugt region, West Greenland : a review , 2007 .
[10] Roger J. Braithwaite. Positive degree-day factors for ablation on the Greenland ice sheet studied by energy-balance modelling , 1995 .
[11] J. Severinghaus,et al. High variability of Greenland surface temperature over the past 4000 years estimated from trapped air in an ice core , 2011 .
[12] N. Reeh,et al. Holocene climatic records from Agassiz Ice Cap, Ellesmere Island, NWT, Canada , 1995 .
[13] N. Reeh,et al. History of a Stable Ice MARGIN—EAST Greenland during the Middle and Upper Pleistocene , 1998 .
[14] D. L. Anderson,et al. Preliminary reference earth model , 1981 .
[15] J. Andrews,et al. Spatial and temporal patterns of iceberg rafting (IRD) along the East Greenland margin, ca. 68°N, over the last 14 cal.ka , 1997 .
[16] M. Stuiver,et al. Radiocarbon-Dated Postglacial Delevelling in Northeast Greenland and Its Implications , 1962 .
[17] K. Lambeck,et al. Constraints on the Greenland Ice Sheet since the Last Glacial Maximum from sea-level observations and glacial-rebound models , 2004 .
[18] A. Aldahan,et al. Be-10 ages from central east Greenland constrain the extent of the Greenland ice sheet during the Last Glacial Maximum , 2007 .
[19] W. Jokat,et al. Submarine end moraines on the continental shelf off NE Greenland – Implications for Lateglacial dynamics , 2010 .
[20] K. Kjær,et al. Early to middle Holocene valley glaciations on northernmost Greenland , 2010 .
[21] B. Elberling,et al. Holocene environmental reconstruction from deltaic deposits in northeast Greenland , 2002 .
[22] J. Andrews,et al. An extensive and dynamic ice sheet on the West Greenland shelf during the last glacial cycle. , 2013 .
[23] Patrick Wu,et al. The effect of earth rheology and ice-sheet size on fault slip and magnitude of postglacial earthquakes , 2014 .
[24] Richard B. Alley,et al. Large Arctic Temperature Change at the Wisconsin-Holocene Glacial Transition , 1995, Science.
[25] K. Hutter. Theoretical Glaciology: Material Science of Ice and the Mechanics of Glaciers and Ice Sheets , 1983 .
[26] J. Mitrovica,et al. On post-glacial sea level – II. Numerical formulation and comparative results on spherically symmetric models , 2005 .
[27] M. Berglund. The architecture at three Saqqaq sites in the Nuuk Fjord, Greenland , 2005 .
[28] O. Bennike,et al. Chironomids as indicators of the Holocene climatic and environmental history of two lakes in Northeast Greenland , 2011 .
[29] John England. Coalescent Greenland and Innuitian ice during the Last Glacial Maximum: revising the Quaternary of the Canadian High Arctic , 1999 .
[30] Eric Rignot,et al. Ice flow in Greenland for the International Polar Year 2008–2009 , 2012 .
[31] Philippe Huybrechts,et al. The treatment of meltwater retention in mass-balance parameterizations of the Greenland ice sheet , 2000, Annals of Glaciology.
[32] H. Oerter,et al. The recession of the inland ice margin during the Holocene climatic optimum in the Jakobshavn Isfjord area of West Greenland , 1990 .
[33] J. Mitrovica,et al. On post-glacial sea level: I. General theory , 2003 .
[34] W. Peltier,et al. Greenland glacial history and local geodynamic consequences , 2002 .
[35] O. Bennike,et al. Late Quaternary development of the southern sector of the Greenland Ice Sheet, with particular reference to the Qassimiut lobe , 2004 .
[36] J. D. Hays,et al. The orbital theory of Pleistocene climate : Support from a revised chronology of the marine δ^ O record. , 1984 .
[37] R. Wal. The importance of thermodynamics for modeling the volume of the Greenland Ice Sheet , 1999 .
[38] P. Langdon,et al. Holocene temperature history at the western Greenland Ice Sheet margin reconstructed from lake sediments , 2013 .
[39] J. Andrews,et al. Late Quaternary iceberg-rafted detritus events on the Denmark Strait–Southeast Greenland continental slope (∼65°N): related to North Atlantic Heinrich events? , 1998 .
[40] N. Nørgaard-Pedersen,et al. Restricted impact of Holocene climate variations on the southern Greenland Ice Sheet , 2011 .
[41] A. Abe‐Ouchi,et al. Effects of first-order stress gradients in an ice sheet evaluated by a three-dimensional thermomechanical coupled model , 2003, Annals of Glaciology.
[42] Peter U. Clark,et al. Ice sheets and sea level of the Last Glacial Maximum , 2001 .
[43] Ingo Sasgen,et al. Limits in detecting acceleration of ice sheet mass loss due to climate variability , 2013 .
[44] J. Mitrovica,et al. Barbados-based estimate of ice volume at Last Glacial Maximum affected by subducted plate , 2013 .
[45] A. Kuijpers,et al. A diatom-based reconstruction of Early Holocene hydrographic and climatic change in a southwest Greenland fjord , 2009 .
[46] Morten Rasch,et al. Holocene Relative Sea Level Changes in Disko Bugt, West Greenland , 2000 .
[47] A. Weidick,et al. Greenland Ice Sheet History Since the Last Glaciation , 1974, Quaternary Research.
[48] C. Hjort. Glaciation, climate history, changing marine levels and the evolution of the Northeast Water polynya , 1997 .
[49] O. Bennike,et al. Late Quaternary history around Nioghalvfjerdsfjorden and Jøkelbugten, North‐East Greenland , 2001 .
[50] Philippe Huybrechts,et al. The Dynamic Response of the Greenland and Antarctic Ice Sheets to Multiple-Century Climatic Warming , 1999 .
[51] G. Sommerhoff. Geomorphologische Prozesse in der Labrador- und Irmingersee. Ein Beitrag zur submarinen Geomorphologie einer subpolaren Meeresregion , 1981 .
[52] D. Pollard,et al. A 3-D coupled ice sheet – sea level model applied to Antarctica through the last 40 ky , 2013 .
[53] Bernd Wagner,et al. Relative sea level changes during the Holocene in the Sisimiut area, south‐western Greenland , 2011 .
[54] Eric Rignot,et al. A Reconciled Estimate of Ice-Sheet Mass Balance , 2012, Science.
[55] J. Mitrovica,et al. Postglacial sea-level change on a rotating Earth , 1998 .
[56] S. Lassen,et al. Late Quaternary sedimentary processes and ocean circulation changes at the Southeast Greenland margin , 2003 .
[57] Svante Björck,et al. Chronology of the last recession of the Greenland Ice Sheet , 2002 .
[58] N. Reeh,et al. The Greenland ice sheet through the last glacial-interglacial cycle , 1991 .
[59] David H. Roberts,et al. Isolation basin stratigraphy and Holocene relative sea-level change on Arveprinsen Ejland, Disko Bugt, West Greenland , 1999 .
[60] S. Funder. QUATERNARY GEOLOGY OF THE ICE-FREE AREAS AND ADJACENT SHELVES OF GREENLAND , 1989 .
[61] K. Mosegaard,et al. Past temperatures directly from the greenland ice sheet , 1998, Science.
[62] O. Bennike. An early Holocene Greenland whale from Melville Bugt, Greenland , 2008, Quaternary Research.
[63] K. Lambeck,et al. Relative sea‐level changes since 15 000 cal. yr BP in the Nanortalik area, southern Greenland , 2006 .
[64] K. Mosegaard,et al. A first detailed look at the Greenland lithosphere and upper mantle, using Rayleigh wave tomography , 2004 .
[65] Marie-Louise Siggaard-Andersen,et al. High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years , 2008, Science.
[66] Paul Johnston,et al. Timing of the Last Glacial Maximum from observed sea-level minima , 2000, Nature.
[67] M. Zreda,et al. Unblocking of the Nares Strait by Greenland and Ellesmere ice-sheet retreat 10,000 years ago , 1999, Nature.
[68] A. Aldahan,et al. Late Pleistocene glacial history of Jameson Land, central East Greenland, derived from cosmogenic 10Be and 26Al exposure dating , 2009 .
[69] O. Bennike,et al. Revision of the early Holocene lake sediment based chronology and event stratigraphy on Hochstetter Forland, NE Greenland , 2008 .
[70] D. Schrag,et al. Estimating past continental ice volume from sea-level data. , 2002 .
[71] G. Denton,et al. Relative sea-level change, Kjove Land, Scoresby Sund, East Greenland: Implications for seasonality in Younger Dryas time , 2008 .
[72] J. Mienert,et al. Submarine glacigenic debris flows, deep-sea channels and past ice-stream behaviour of the East Greenland continental margin , 2006 .
[73] J. Johansson,et al. Space-Geodetic Constraints on Glacial Isostatic Adjustment in Fennoscandia , 2001, Science.
[74] A. Kroon,et al. Holocene sea‐level reconstruction in the Young Sound region, Northeast Greenland , 2011 .
[75] J. Briner,et al. Rapid ice retreat in Disko Bugt supported by 10Be dating of the last recession of the western Greenland Ice Sheet , 2013 .
[76] M. Houmark‐Nielsen,et al. Quaternary glacial and marine environmental history of Northwest Greenland : a review and reappraisal. , 1999 .
[77] A. Paulson,et al. The rotational stability of an ice-age earth , 2005 .
[78] Milton A. Trautman. Isotopes, Inc. radiocarbon measurements [Part] 3. , 2006 .
[79] Regine Hock,et al. Temperature index melt modelling in mountain areas , 2003 .
[80] W. Peltier. The impulse response of a Maxwell Earth , 1974 .
[81] J. Oerlemans,et al. Effects of spatial discretization in ice-sheet modelling using the shallow-ice approximation , 2006, Journal of Glaciology.
[82] D. Fredh. Holocene relative sea-level changes in the Tasiusaq area, southern Greenland, with focus on the Ta4 basin , 2008 .
[83] J. Dowdeswell,et al. Submarine landforms and shallow acoustic stratigraphy of a 400 km-long fjord-shelf-slope transect, Kangerlussuaq margin, East Greenland , 2010 .
[84] Paul Johnston,et al. Reply to comment by W. Fjeldskaar ‘What about the asthenosphere viscosity? Sea‐level change, glacial rebound and mantle viscosity for northern Europe’ , 2000 .
[85] B. Fredskild,et al. Holocene changes in climate and vegetation in the Ammassalik area, East Greenland, recorded in lake sediments and soil profiles , 2008 .
[86] J. Mienert,et al. Timing and significance of glacially influenced mass-wasting in the submarine channels of the Greenland Basin , 2004 .
[87] David M. Holland,et al. Acceleration of Jakobshavn Isbræ triggered by warm subsurface ocean waters , 2008 .
[88] J. Dowdeswell,et al. Late Quaternary sedimentation in Kejser Franz Joseph Fjord and the continental margin of East Greenland , 2002, Geological Society, London, Special Publications.
[89] K. Lambeck,et al. Holocene relative sea‐level changes in the Qaqortoq area, southern Greenland , 2006 .
[90] A. Jennings,et al. Middle and late quaternary glacial limits in greenland , 2004 .
[91] K. Lambeck,et al. Into and out of the Last Glacial Maximum: sea-level change during Oxygen Isotope Stages 3 and 2 , 2002 .
[92] H. Grobe,et al. Late Quaternary glacial history and short-term ice-rafted debris fluctuations along the East Greenland continental margin , 1996, Geological Society, London, Special Publications.
[93] J. Severinghaus,et al. A revised +10±4 °C magnitude of the abrupt change in Greenland temperature at the Younger Dryas termination using published GISP2 gas isotope data and air thermal diffusion constants , 2005 .
[94] G. Denton,et al. Relative sea-level changes, Schuchert Dal, East Greenland, with implications for ice extent in late-glacial and Holocene times , 2010 .
[95] W. Peltier. GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE , 2004 .
[96] D. H. Roberts,et al. Early Holocene history of the west Greenland Ice Sheet and the GH-8.2 event , 2006 .
[97] C. Hjort. A glacial chronology for northern East Greenland , 2008 .
[98] Eric Rignot,et al. Continental scale, high order, high spatial resolution, ice sheet modeling using the Ice Sheet System Model (ISSM) , 2012 .
[99] K. Kjær,et al. Late Quaternary glaciation history of northernmost Greenland - evidence of shelf-based ice , 2010 .
[100] Radford M. Neal,et al. A data-calibrated distribution of deglacial chronologies for the North American ice complex from glaciological modeling , 2012 .
[101] O. Bennike,et al. Late Quaternary history of the Kap Mackenzie area, northeast Greenland , 2010 .
[102] Ó. Ingólfsson,et al. Paleoclimatic implications of an early Holocene glacier advance on Disko Island, West Greenland , 2008 .
[103] Paul Johnston,et al. Sea‐level change, glacial rebound and mantle viscosity fornorthern Europe , 1998 .
[104] D. H. Roberts,et al. Isolation basins, sea-level changes and the Holocene history of the Greenland Ice Sheet , 2011 .
[105] D. H. Roberts,et al. Late Weichselian relative sea-level changes and ice sheet history in southeast Greenland , 2008 .
[106] N. Anderson,et al. Holocene palaeoecology of southwest Greenland inferred from macrofossils in sediments of an oligosaline lake , 2010 .
[107] E. Koster,et al. Implications for Deglaciation Chronology from New AMS Age Determinations in Central West Greenland , 1996, Quaternary Research.
[108] W. Dansgaard,et al. A "deep" ice core from East Greenland , 1992, Meddelelser om Grønland. Geoscience.
[109] E. H. Willis,et al. Isotopes, Inc. Radiocarbon Measurements II , 1962, Radiocarbon: An International Journal of Cosmogenic Isotope Research.
[110] O. Bennike. Palaeoecology of two lake basins from Disko, West Greenland , 1995 .
[111] W. Blake. Glaciated landscapes along Smith Sound, Ellesmere Island, Canada and Greenland , 1999, Annals of Glaciology.
[112] A. Vieli,et al. Controls upon the Last Glacial Maximum deglaciation of the northern Uummannaq Ice Stream System, West Greenland , 2014 .
[113] Y. Vasari,et al. Climatic changes in arctic areas during the last ten-thousand years : A symposium held at Oulanka and Kevo, 4-10 October, 1971 , 1974 .
[114] Dayton Dove,et al. Arctic Ocean glacial history , 2014 .
[115] D. Fisher,et al. A record of Holocene summer climate from a Canadian high-Arctic ice core , 1990, Nature.
[116] S. Shyam Sunder,et al. Creep of Polycrystalline Ice , 1990 .
[117] Nicholas John Anderson,et al. Holocene thermal maximum in the western Arctic (0-180°W) , 2004 .
[118] A. Kuijpers,et al. Giant iceberg plow marks at more than 1 km water depth offshore West Greenland , 2007 .
[119] C. Hjort,et al. The subfossil occurrence of Mytilus edulis L. in central East Greenland , 2008 .
[120] P. Huybrechts,et al. Glacial-Geological/Geomorphological Research in West Greenland Used to Test an Ice-Sheet Model , 1995, Quaternary Research.
[121] R. Virginia,et al. Age of the Ørkendalen moraines, Kangerlussuaq, Greenland: constraints on the extent of the southwestern margin of the Greenland Ice Sheet during the Holocene , 2012 .
[122] C. Bryant,et al. Using relative sea-level data to constrain the deglacial and Holocene history of southern Greenland. , 2014 .
[123] H. Stewart,et al. Using proglacial-threshold lakes to constrain fluctuations of the Jakobshavn Isbræ ice margin, western Greenland, during the Holocene , 2010 .
[124] K. Cuffey. Methodology for use of isotopic climate forcings in ice sheet models , 2000 .
[125] D. H. Roberts,et al. Late Weichselian deglacial history of Disko Bugt, West Greenland, and the dynamics of the Jakobshavns Isbrae ice stream , 2003 .
[126] D. Raynaud,et al. Holocene thinning of the Greenland ice sheet , 2009, Nature.
[127] André Berger,et al. Milankovitch and Climate , 1984, NATO ASI Series.
[128] D. H. Roberts,et al. A revised chronology for the ‘Fjord Stade’ moraine in Disko Bugt, west Greenland , 2002 .
[129] C. Zweck,et al. Modeling the marine extent of Northern Hemisphere ice sheets during the last glacial cycle , 2003, Annals of Glaciology.
[130] C. Zweck,et al. Modeling of the northern hemisphere ice sheets during the last glacial cycle and glaciological sensitivity , 2005 .
[131] A. Kuijpers,et al. Variable North Atlantic climate seesaw patterns documented by a late Holocene marine record from Disko Bugt, West Greenland , 2008 .
[132] J. Dowdeswell,et al. Late Quaternary ice flow in a West Greenland fjord and cross-shelf trough system: submarine landforms from Rink Isbrae to Uummannaq shelf and slope , 2014 .
[133] K. Kjær,et al. The Greenland ice sheet during the past 300,000 years: a review , 2011 .
[134] H. Goosse,et al. A 10,000-Year Record of Arctic Ocean Sea-Ice Variability—View from the Beach , 2011, Science.
[135] Sivaprasad Gogineni,et al. A new ice thickness and bed data set for the Greenland ice sheet: 1. Measurement, data reduction, and errors , 2001 .
[136] Richard B. Alley,et al. History of the Greenland Ice Sheet: paleoclimatic insights , 2010 .
[137] Son V. Nghiem,et al. The extreme melt across the Greenland ice sheet in 2012 , 2012 .
[138] R. Bindschadler. Jakobshavns Glacier drainage basin - A balance assessment , 1984 .
[139] W. Peltier,et al. Global Changes in Postglacial Sea Level: A Numerical Calculation , 1978, Quaternary Research.
[140] J. Gregory,et al. Twentieth-century global-mean sea-level rise: is the whole greater than the sum of the parts? , 2013 .
[141] J. Landvik. The last glaciation of Germania Land and adjacent areas, northeast Greenland , 1994 .
[142] D. H. Roberts,et al. New observations on the relative sea level and deglacial history of Greenland from Innaarsuit, Disko Bugt , 2003, Quaternary Research.
[143] Eric Rignot,et al. A Reconciled Estimate of Ice-Sheet Mass Balance , 2012, Science.
[144] P. Wadhams,et al. Marine geophysical evidence for former expansion and flow of the Greenland Ice Sheet across the north‐east Greenland continental shelf , 2009 .
[145] C. Hjort. Glaciation in northern East Greenland during the Late Weichselian and Early Flandrian , 2008 .
[146] T. Lowell,et al. Fluctuations of local glaciers in Greenland during latest Pleistocene and Holocene time , 2009 .
[147] Peter J. Bradbury,et al. The Last Glacial Maximum , 2009, Science.
[148] J. Andrews. The role of the Iceland Ice Sheet in the North Atlantic during the late Quaternary: a review and evidence from Denmark Strait , 2008 .
[149] M. Kosnik,et al. Amino acid ratios in reworked marine bivalve shells constrain Greenland Ice Sheet history during the Holocene , 2014 .
[150] A. Kuijpers,et al. Early Holocene palaeoceanography and deglacial chronology of Disko Bugt, West Greenland , 2005 .
[151] F. Gillet-Chaulet,et al. Interactive comment on “ Greenland Ice Sheet contribution to sea-level rise from a new-generation icesheet model ” , 2012 .
[152] D. R. Baral. Asymptotic theories of large scale motion, temperature and moisture distributions in land based polythermal ice shields and in floating ice shelves: a critical review and new developments , 1999 .
[153] G. Milne,et al. Calibrating a glaciological model of the Greenland ice sheet from the Last Glacial Maximum to present-day using field observations of relative sea level and ice extent , 2009 .
[154] V. K. Prest,et al. Late Wisconsinan and Holocene retreat of the Laurentide ice sheet : map 1702A , 1987 .
[155] J. England. The late Quaternary history of Hall Land, northwest Greenland: Reply , 1985 .
[156] Daniel F. Martin,et al. Adaptive mesh, finite volume modeling of marine ice sheets , 2013, J. Comput. Phys..
[157] S. Funder,et al. Palynology in a polar desert, eastern North Greenland , 2008 .
[158] On Postglacial Sea Level , 2007 .
[159] O. Bennike,et al. Repeated short-term bioproductivity changes in a coastal lake on Store Koldewey, northeast Greenland: an indicator of varying sea-ice coverage? , 2009 .
[160] C. Sparrenbom. Constraining the Southern Part of the Greenland Ice Sheet since the Last Glacial Maximum from Relative Sea-Level Changes, Cosmogenic Dates and Glacial-Isostatic Adjustment Models , 2006 .
[161] Kurt Lambeck,et al. Estimates of South Greenland late-glacial ice limits from a new relative sea level curve , 2002 .
[162] W. Peltier,et al. A complete formalism for the inversion of post-glacial rebound data: resolving power analysis , 1991 .
[163] K. Kjær,et al. Rapid early Holocene ice retreat in West Greenland , 2014 .
[164] J. Andrews,et al. Freshwater forcing from the Greenland Ice Sheet during the Younger Dryas: evidence from southeastern Greenland shelf cores , 2006 .
[165] N. Nørgaard-Pedersen,et al. 8000 year marine record of climate variability and fjord dynamics from Southern Greenland , 2009 .
[166] Anne M. Le Brocq,et al. A deglacial model for Antarctica: geological constraints and glaciological modelling as a basis for a new model of Antarctic glacial isostatic adjustment , 2012 .
[167] P. Huybrechts. Basal temperature conditions of the Greenland ice sheet during the glacial cycles , 1996, Annals of Glaciology.
[168] Gaël Durand,et al. Greenland ice sheet contribution to sea-level rise from a new-generation ice-sheet model , 2012 .
[169] W. Peltier,et al. Glacial-Isostatic Adjustment—I. The Forward Problem , 2007 .
[170] O. Bennike. Late Quaternary history of Washington Land, North Greenland , 2002 .
[171] J. Jouzel,et al. Evidence for general instability of past climate from a 250-kyr ice-core record , 1993, Nature.
[172] D. R. Baral,et al. Asymptotic Theories of Large-Scale Motion, Temperature, and Moisture Distribution in Land-Based Polythermal Ice Sheets: A Critical Review and New Developments , 2001 .
[173] Kenji Kawamura,et al. Eemian interglacial reconstructed from a Greenland folded ice core , 2013, Nature.
[174] Maik Thomas,et al. Heat flux variations beneath central Greenland’s ice due to anomalously thin lithosphere , 2013 .
[175] D. H. Roberts,et al. Late Holocene relative sea level rise and the Neoglacial history of the Greenland ice sheet , 2009 .
[176] Sheng Xu,et al. Ice sheet extent and early deglacial history of the southwestern sector of the Greenland Ice Sheet , 2009 .