D. Macayeal

发表

Modeling surface-roughness/solar-ablation feedback: application to small-scale surface channels and crevasses of the Greenland ice sheet

L. Cathles, D. Abbot, J. Bassis, 2011, Annals of Glaciology.

Air-Snow Interactions and Atmospheric Chemistry

D. Macayeal, I. Joughin, W. Krabill, 2002 .

Derived Characteristics of the Ross Ice Shelf, Antarctica

D. Macayeal, R. Thomas, 1982 .

Derived Characteristics of the Ross Ice Shelf, Antarctica (Abstract only)

D. Macayeal, R. Thomas, 1982 .

Catastrophic ice-shelf break-up by an ice-shelf-fragment-capsize mechanism

D. Macayeal, T. Scambos, M. Fahnestock, 2003, Journal of Glaciology.

Ice dynamics at the mouth of ice stream B, Antarctica

D. Macayeal, R. Bindschadler, S. Stephenson, 1987 .

The Ross Ice Shelf Geophysical and Glaciological Survey (RIGGS) : introduction and summary of measurements performed . Glaciological studies on the Ross Ice Shelf, Antarctica, 1973-1978

Douglas R. Macayeal, Charles R. Bentley, D. Macayeal, 2013 .

Large‐scale ice flow over a viscous basal sediment: Theory and application to ice stream B, Antarctica

Douglas R. Macayeal, D. Macayeal, 1989 .

Calving of large tabular icebergs from ice shelf rift systems

Ian Joughin, D. Macayeal, I. Joughin, 2005 .

Tabular iceberg collisions within the coastal regime

D. Macayeal, A. Bliss, Young-Jin Kim, 2008, Journal of Glaciology.

Tidal Modulation of Ice-shelf Flow: a Viscous Model of the Ross Ice Shelf

D. Macayeal, K. Brunt, 2014 .

Transoceanic infragravity waves impacting Antarctic ice shelves

D. Macayeal, P. Bromirski, O. Sergienko, 2010 .

Antarctic ice-shelf calving triggered by the Honshu (Japan) earthquake and tsunami, March 2011

Kelly M. Brunt, Emile A. Okal, E. Okal, 2011, Journal of Glaciology.

Formulation of ice shelf dynamic boundary conditions in terms of a Coulomb rheology

D. Macayeal, C. Bentley, S. King, 1986 .

Ambient seismic, hydroacoustic, and flexural gravity wave noise on a tabular iceberg

E. Okal, D. Macayeal, Yitang Wang, 2015 .

A numerical investigation of ice-lobe-permafrost interaction around the southern Laurentide ice sheet

D. Macayeal, D. Mickelson, P. M. Colgan, 2000 .

Stick–slip behavior of ice streams: modeling investigations

Douglas R. Macayeal, D. Macayeal, O. Sergienko, 2009, Annals of Glaciology.

Acceleration of Pine Island and Thwaites Glaciers, West Antarctica

Eric Rignot, Marjorie Schmeltz, David G. Vaughan, 2002, Annals of Glaciology.

Breakup of the Larsen B Ice Shelf triggered by chain reaction drainage of supraglacial lakes

D. Macayeal, O. Sergienko, Douglas R. MacAyeal, 2013 .

The Effects of Basal Melting on the Present Flow of the Ross Ice Shelf, Antarctica

D. Macayeal, R. Thomas, R. Thomas, 1986, Journal of Glaciology.

Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study

D. Macayeal, E. Rignot, T. Dupont, 2002, Journal of Glaciology.

Flow of the Ross Ice Shelf, Antarctica, is modulated by the ocean tide

Matt A. King, D. Macayeal, H. Fricker, 2010, Journal of Glaciology.

Integrating satellite observations with modelling: basal shear stress of the Filcher-Ronne ice streams, Antarctica

S. Tulaczyk, D. Macayeal, T. Scambos, 2006, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

Diurnal lake-level cycles on ice shelves driven by meltwater input and ocean tidal tilt

D. Macayeal, Grant J. Macdonald, I. Willis, 2020, Journal of Glaciology.

Ice-shelf Dynamics Near the Front of Filchner-Ronne Ice Shelf, Antarctica, Revealed by SAR Interferometry: Model/Interferogram Comparison

D. Macayeal, E. Rignot, C. Hulbe, 1998 .

Direct measurements of ice-shelf flexure caused by surface meltwater ponding and drainage

D. Macayeal, Grant J. Macdonald, I. Willis, 2019, Nature Communications.

Surface melting on Larsen Ice Shelf, Antarctica

D. Macayeal, O. Sergienko, 2005, Annals of Glaciology.

Challenging an Ice-Core Paleothermometer

D. Macayeal, 1995, Science.

Deglaciation of a Soft-Bedded Laurentide Ice Sheet

D. Macayeal, P. Clark, J. Jenson, 1998 .

Basal friction of Ice Stream E, West Antarctica

D. Macayeal, R. Bindschadler, T. Scambos, 1995 .

Tabular Icebergs in the South Atlantic: Melt Ponding, Melt Pond Geometry and Margin Evolution.

Theodore A. Scambos, James L. Fastook, Douglas R. Macayeal, 2004 .

Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study

D. Macayeal, E. Rignot, T. Dupont, 2002, Journal of Glaciology.

Transoceanic infragravity waves impacting Antarctic ice shelves

D. Macayeal, P. Bromirski, O. Sergienko, 2010 .

Calving and rifting on the McMurdo Ice Shelf, Antarctica

D. Macayeal, Grant J. Macdonald, D. Mayer, 2017, Annals of Glaciology.

Flexural-gravity wave phenomena on ice shelves.

D. Macayeal, O. Sergienko, C. Hulbe, 2008 .

Seismic observations of glaciogenic ocean waves (micro-tsunamis) on icebergs and ice shelves

E. Okal, J. Bassis, D. Macayeal, 2009, Journal of Glaciology.

Paleothermometry redux

D. Macayeal, E. Waddington, J. Firestone, 1993, Journal of Glaciology.

Kinematic and seismic analysis of giant tabular iceberg breakup at Cape Adare, Antarctica

E. Okal, D. Macayeal, T. Scambos, 2010 .

Observations of unusual fast-ice conditions in the southwest Ross Sea, Antarctica: preliminary analysis of iceberg and storminess effects

D. Macayeal, O. Sergienko, K. Brunt, 2006, Annals of Glaciology.

Paleoclimatic constraints on the maintenance of possible ice-shelf cover in the Norwegian and Greenland seas

D. Macayeal, D. Lindstrom, 1986 .

An ice-shelf model test based on the Ross Ice Shelf, Antarctica

C. Ritz, D. Macayeal, P. Huybrechts, 1996, Annals of Glaciology.

A Catastrophe Model of the Paleoglimate

D. Macayeal, 1979, Journal of Glaciology.

Melting and freezing beneath the Ross ice streams, Antarctica

S. Tulaczyk, D. Macayeal, I. Joughin, 2004, Journal of Glaciology.

Ice‐rafted debris associated with binge/purge oscillations of the Laurentide Ice Sheet

R. Alley, D. Macayeal, 1994 .

Ice-rafted debris associated with binge/purge oscillations of the Laurentide Ice Sheet R. B. Alley

D. Macayeal, 1994 .

Bedforms of Thwaites Glacier, West Antarctica: Character and Origin

D. Macayeal, K. Christianson, L. Zoet, 2021, Journal of Geophysical Research: Earth Surface.

Death of an ice sheet

D. Macayeal, D. Lindstrom, 1993, Nature.

Scandinavian, Siberian, and Arctic Ocean Glaciation: Effect of Holocene Atmospheric CO2 Variations

D. Macayeal, D. Lindstrom, 1989, Science.

Tidal Rectification Below the Ross Ice Shelf, Antarctica

D. Macayeal, 2013 .

Ice-shelf dynamics near the front of the Filchner—Ronne Ice Shelf, Antarctica, revealed by SAR interferometry

D. Macayeal, E. Rignot, 1998, Journal of Glaciology.

Ice sheets play important role in climate change

J. Andrews, D. Macayeal, P. Clark, 1995, Eos, Transactions American Geophysical Union.

A low‐order model of the Heinrich Event Cycle

D. Macayeal, 1993 .

Effects of Glaciation on Methane-Hydrate Stability

D. Macayeal, D. Lindstrom, 1990 .

Paleothermometry by control methods

D. Macayeal, E. Waddington, J. Firestone, 1991, Journal of Glaciology.

Dynamic/thermodynamic simulations of Laurentide ice-sheet instability

D. Macayeal, R. Greve, 1996 .

Large-scale rheology of the Ross Ice Shelf, Antarctica, computed by a control method

D. Macayeal, V. Rommelaere, 1997, Annals of Glaciology.

Dynamic/thermodynamic simulations of Laurentide ice-sheet instability

D. Macayeal, R. Greve, 1996, Annals of Glaciology.

Palaeoclimate: Ocean tides and Heinrich events

D. Macayeal, J. Mitrovica, G. Milne, 2004, Nature.

The influence of ice melange on fjord seiches

D. Macayeal, Wendy W. Zhang, J. Amundson, 2012, Annals of Glaciology.

Interactions of wind‐transported snow with a rift in the Ross Ice Shelf, Antarctica

S. Jacobs, D. Macayeal, L. Tremblay, 2008 .

ICESat's new perspective on ice shelf rifts: The vertical dimension

J. Bassis, D. Macayeal, H. Fricker, 2005 .

Ephemeral grounding as a signal of ice-shelf change

Eric Rignot, Marjorie Schmeltz, D. Macayeal, 2001, Journal of Glaciology.

Comparison of ice-shelf creep flow simulations with ice-front motion of Filchner-Ronne Ice Shelf, Antarctica, detected by SAR interferometry

D. Macayeal, E. Rignot, C. Hulbe, 1998, Annals of Glaciology.

Numerical modeling of advective transport of saturated deforming sediment beneath the Lake Michigan

D. Macayeal, P. Clark, J. Jenson, 1995 .

Influence of the Great Lakes on the dynamics of the southern Laurentide ice sheet: Numerical experiments

D. Macayeal, D. Mickelson, P. M. Colgan, 2001 .

Derived Characteristics of the Ross Ice Shelf, Antarctica (Abstract only)

D. Macayeal, R. Thomas, Robert H. Thomas, 1982, Annals of Glaciology.

Distribution of Net Mass Balance in the Vicinity of Crary Ice Rise, Antarctica

D. Macayeal, R. Bindschadler, E. Roberts, 1989, Journal of Glaciology.

Force, Mass, and Energy Budgets of the Crary Ice Rise Complex, Antarctica

D. Macayeal, C. Bentley, S. Shabtaie, 1987, Journal of Glaciology.

Numerical models of the Filchner‐Ronne Ice Shelf: An assessment of reinterpreted ice thickness distributions

D. Macayeal, M. Lange, 1986 .

Derived Characteristics of the Ross Ice Shelf, Antarctica

D. Macayeal, R. Thomas, 1982, Journal of Glaciology.

Morphology of Mars North Polar Ice Cap

H. Zwally, D. Macayeal, A. Fountain, 2000 .

Seismology Gets Under the Skin of the Antarctic Ice Sheet

D. Macayeal, 2018, Geophysical Research Letters.

The flexural dynamics of melting ice shelves

D. Macayeal, O. Sergienko, 2013, Annals of Glaciology.

Ross Ice Shelf temperatures support a history of ice-shelf thickening

D. Macayeal, R. Thomas, 1979, Nature.

THE CREEP OF ICE, ROOSEVELT GEOTHERMAL HEAT FLOW, ISLAND, ANT ARCTICA* AND

D. Macayeal, C. Bentley, R. Thomas, 2010 .

The mass balance of a cirque glacier in the Italian Alps (Ghiacciaio della Sforzellina, Ortles-Cevedale Group)

D. Macayeal, 1993 .

Numerical models of ice-shelf flow: ideal/real

D. Macayeal, M. Lange, 1989 .

Effects of Rigid Body Collisions and Tide-Forced Drift on Large Tabular Icebergs of the Antarctic

L. Gray, M. R. Drinkwater, T. Scambos, 2001 .

The Recent Advance of the Ross Ice Shelf Antarctica

S. Jacobs, D. Macayeal, J. Ardai, 1986, Journal of Glaciology.

Optimal Measurement of Ice-Sheet deformation from Surface-Marker Arrays

D. Macayeal, 1985, Journal of Glaciology.

Revisiting Weertman's tombstone bed

D. Macayeal, 2019, Annals of Glaciology.

Traveling supraglacial lakes on George VI Ice Shelf, Antarctica

D. Macayeal, C. Labarbera, 2011 .

An investigation of low‐stress ice rheology on the Ward‐Hunt Ice Shelf

D. Macayeal, G. Holdsworth, 1986 .

Ice-shelf Response to Ice-stream Discharge Fluctuations: II. Ideal Rectangular Ice Shelf

D. Macayeal, M. Lange, 1988, Journal of Glaciology.

Seismic Recording on Drifting Icebergs: Catching Seismic Waves, Tsunamis and Storms from Sumatra and Elsewhere

E. Okal, D. Macayeal, 2006 .

Ice-shelf dynamics near the front of the Filchner-Ronne Ice Shelf, Antaretica, revealed by SAR interferometry: model/interferogram comparison

D. Macayeal, E. Rignot, C. Hulbe, 1998, Journal of Glaciology.

Binge/purge oscillations of the Laurentide Ice Sheet as a cause of the North Atlantic's Heinrich events

D. Macayeal, 1993 .

Evolution of Tidally Triggered Meltwater Plumes Below Ice Shelves

D. Macayeal, 2013 .

Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica

D. Macayeal, D. Mayer, I. Willis, 2019, Journal of Glaciology.

Diurnal seismicity cycle linked to subsurface melting on an ice shelf

E. Okal, D. Macayeal, I. Willis, 2018, Annals of Glaciology.

Seismic and hydroacoustic tremor generated by colliding icebergs

E. Okal, J. Bassis, D. Macayeal, 2008 .

Irregular oscillations of the West Antarctic ice sheet

D. Macayeal, Douglas R. MacAyeal, 1992, Nature.

Numerical reconstruction of a soft-bedded Laurentide Ice Sheet during the last glacial maximum

D. Macayeal, P. Clark, J. Jenson, 1996 .

A new numerical model of coupled inland ice sheet, ice stream, and ice shelf flow and its application to the West Antarctic Ice Sheet

D. Macayeal, C. Hulbe, 1999 .

Numerical modeling of subglacial sediment deformation: Implications for the behavior of the Lake Michigan Lobe, Laurentide Ice Sheet

D. Macayeal, P. Clark, J. Jenson, 1996 .

Tidal flexure along ice-sheet margins: comparison of InSAR with an elastic-plate model

Eric Rignot, Marjorie Schmeltz, D. Macayeal, 2002, Annals of Glaciology.

Observation and analysis of ice flow in the largest Greenland ice stream

Prasad Gogineni, Ian Joughin, Jonathan L. Bamber, 2001 .

Observation of ocean tides below the Filchner and Ronne Ice Shelves, Antarctica, using synthetic aperture radar interferometry: Comparison with tide model predictions

D. Macayeal, E. Rignot, L. Padman, 2000 .

On the recent calving of icebergs from the Ross ice shelf

K. C. Jezek, M. A. Lazzara, D. Macayeal, 1999 .

Ice-Shelf Flow at the Boundary of Crary Ice Rise, Antarctica

D. Macayeal, R. Bindschadler, P. Vornberger, 1988, Annals of Glaciology.

Numerical simulations of the Ross Sea tides

D. Macayeal, 1984 .

Thermohaline circulation below the Ross Ice Shelf: A consequence of tidally induced vertical mixing and basal melting

D. Macayeal, 1984 .

Seasonal evolution of supraglacial lakes on a floating ice tongue, Petermann Glacier, Greenland

D. Macayeal, Grant J. Macdonald, Douglas R. MacAyeal, 2018, Annals of Glaciology.

Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes

D. Macayeal, A. Banwell, 2015, Antarctic Science.

Supraglacial lakes on the Larsen B ice shelf, Antarctica, and at Paakitsoq, West Greenland: a comparative study

N. Glasser, D. Macayeal, N. Arnold, 2014, Annals of Glaciology.

Laboratory investigations of iceberg capsize dynamics, energy dissipation and tsunamigenesis

D. Abbot, D. Macayeal, N. Guttenberg, 2012 .

A computational investigation of iceberg capsize as a driver of explosive ice-shelf disintegration

D. Abbot, D. Macayeal, N. Guttenberg, 2011, Annals of Glaciology.

Ice Stream-Ice Shelf Interaction in West Antarctica

D. Macayeal, R. Bindschadler, S. Stephenson, 1987 .

Ice–shelf Grounding: Ice and Bedrock Temperature Changes

D. Macayeal, R. Thomas, 1980, Journal of Glaciology.

Basal shear stress of the Ross ice streams from control method inversions

Ian Joughin, S. Tulaczyk, D. Macayeal, 2004 .

A tutorial on the use of control methods in ice-sheet modeling

Douglas R. Macayeal, D. Macayeal, 1993, Journal of Glaciology.

An ice-shelf model test based on the Ross Ice Shelf, Antarctica

Philippe Huybrechts, Douglas R. Macayeal, C. Ritz, 1996, Annals of Glaciology.

Assessing Potential Contributions from Outgassing and Tidal Effects on the Evolving Rotational State of 1I/'Oumuamua

D. Macayeal, K. Meech, O. Hainaut, 2022, 2209.15074.

The basal stress distribution of Ice Stream E, Antarctica, inferred by control methods

D. Macayeal, 1992 .

Drifting snow threshold measurements near McMurdo station, Antarctica: a sensor comparison study

D. Macayeal, L. Tremblay, J. Thom, 2012 .

An ice-shelf 1 D 0 del test based on the Ross Ice Shelf , Antarctica

D. Macayeal, P. Huybrechts, C. Hulbe, 2018 .

The PSU/UofC finite-element thermomechanical flowline model of ice-sheet evolution

R. Alley, D. Macayeal, B. Parizek, 2005 .

A model of viscoelastic ice-shelf flexure

D. Macayeal, O. Sergienko, A. Banwell, 2015 .

On the factors behind large Labrador Sea tides during the last glacial cycle and the potential implications for Heinrich events

D. Macayeal, J. Mitrovica, G. Milne, 2008 .

Numerical Simulations of Tidal Deformation and Resulting Light Curves of Small Bodies: Material Constraints of 99942 Apophis and 1I/‘Oumuamua

D. Macayeal, K. Meech, O. Hainaut, 2022, The Planetary Science Journal.

Ice-shelf Response to Ice-stream Discharge Fluctuations: I. Unconfined Ice Tongues

Victor Barcilon, Douglas R. Macayeal, D. Macayeal, 1988, Journal of Glaciology.

Glaciological Studies on the Ross Ice Shelf, Antarctica, 1973–1978

D. Macayeal, R. Thomas, D. Eilers, 2013 .

Ice-Shelf Backpressure: Form Drag Versus Dynamic Drag

D. Macayeal, 1987 .

Numerical Modeling of Ice-Shelf Motion

D. Macayeal, R. Thomas, 1982, Annals of Glaciology.

West antarctic ice sheet collapse: Chimera or clear danger

R. Alley, D. Macayeal, 1993 .

ICESat profiles of tabular iceberg margins and iceberg breakup at low latitudes

James L. Fastook, Aitbala Sargent, Ted A. Scambos, 2005 .

Interannual climate variability helps define the mean state of glaciers

D. Macayeal, A. Doughty, A. Malone, 2019, Journal of Glaciology.

Glaciers of the McMurdo dry valleys: Terrestrial analog for Martian polar sublimation

D. Macayeal, K. MacClune, A. Fountain, 2003 .

Formation and Dissociation of Clathrate Hydrates on Mars: Polar Caps, Northern Plains and Highlands

Jeffrey S. Kargel, Victor R. Baker, Kenneth L. Tanaka, 2000 .

Ice stream basal conditions from block‐wise surface data inversion and simple regression models of ice stream flow: Application to Bindschadler Ice Stream

D. Macayeal, R. Bindschadler, P. Vornberger, 2008 .

Basal friction of Ice Stream E, West Antarctica

D. Macayeal, R. Bindschadler, T. Scambos, 1995, Journal of Glaciology.

Data report for the Siple Coast (Antarctica) project

D. Macayeal, R. Bindschadler, S. Stephenson, 1988 .

Ice-Shelf Response to Ice-stream Discharge Fluctuations: III. The Effects of Ice-stream Imbalance on the Ross Ice Shelf, Antarctica

D. Macayeal, 1989, Journal of Glaciology.

Iceberg-capsize tsunamigenesis

D. Abbot, D. Macayeal, O. Sergienko, 2011, Annals of Glaciology.

Enigmatic surface rolls of the Ellesmere Ice Shelf

D. Macayeal, O. Sergienko, L. Copland, 2022, Journal of Glaciology.

Effects of Glaciation on Methane-Hydrate Stability

D. Macayeal, D. Lindstrom, 1990, Annals of Glaciology.

Environmental Constraints on West Antarctic Ice-Sheet Formation

D. Macayeal, D. Lindstrom, 1987, Journal of Glaciology.

Transoceanic wave propagation links iceberg calving margins of Antarctica with storms in tropics and Northern Hemisphere

E. Okal, J. Bassis, D. Macayeal, 2006 .

A camera and multisensor automated station design for polar physical and biological systems monitoring: AMIGOS

Theodore A. Scambos, A. Behar, R. Ross, 2012, Journal of Glaciology.

Steady flow of a viscous ice stream across a no-slip/free-slip transition at the bed

D. Macayeal, V. Barcilon, 1993, Journal of Glaciology.

Seismic observations of sea swell on the floating Ross Ice Shelf, Antarctica

Emile A. Okal, E. Okal, D. Macayeal, 2009 .

Break-up of the Larsen B Ice Shelf Triggered by Chain-Reaction 1 Drainage of Supraglacial Lakes 2

D. Macayeal, O. Sergienko, A. Banwell, 2013 .

Direct measurements of ice-shelf flexure caused by surface meltwater ponding and drainage

D. Macayeal, I. Willis, A. Banwell, 2019, Nature Communications.

Mass-balance studies of ice streams A, B, and C, west Antarctica, and possible surging behavior of ice stream B

D. Macayeal, R. Bindschadler, C. Bentley, 1988 .

Mass-Balance Studies of Ice Streams A, B, and C, West Antarctica, and Possible Surging Behavior of Ice Stream Β

D. Macayeal, R. Bindschadler, C. Bentley, 1988, Annals of Glaciology.

The morphology of supraglacial lake ogives

D. Macayeal, J. Amundson, L. M. Cathles, 2013, Journal of Glaciology.

Treatment of ice-shelf evolution combining flow and flexure

D. Macayeal, I. Willis, O. Sergienko, 2021, Journal of Glaciology.

Reconstruction of snow/firn thermal diffusivities from observed temperature variation: application to iceberg C16, Ross Sea, Antarctica, 2004–07

D. Macayeal, O. Sergienko, J. Thom, 2008, Annals of Glaciology.

Blocking a wave: frequency band gaps in ice shelves with periodic crevasses

D. Macayeal, Wendy W. Zhang, J. Amundson, 2011, Annals of Glaciology.

Catastrophic Ice Shelf Breakup as the Source of Heinrich Event Icebergs

D. Macayeal, G. Denton, J. Kleman, 2004 .

Observations: Changes in Snow, Ice and Frozen Ground

L. Hinzman, J. Carrasco, H. Melling, 2007 .

Causes of sudden, short‐term changes in ice‐stream surface elevation

D. Macayeal, Olga V. Sergienko, Rober T Bindschadler, 2007 .

Intra-surface radiative transfer limits the geographic extent of snow penitents on horizontal snowfields

L. Cathles, D. Abbot, D. Macayeal, 2014, Journal of Glaciology.

The Creep of Ice, Geothermal Heat Flow, and Roosevelt Island, Antarctica

D. Macayeal, C. Bentley, R. Thomas, 1980, Journal of Glaciology.

Numerical Models of Ice-Shelf Flow: Ideal/Real

D. Macayeal, M. Lange, 1989, Annals of Glaciology.

Numerical Models of Steady-State Thickness and Basal Ice Configurations of the Central Ronne Ice Shelf, Antarctica

D. Macayeal, M. Lange, 1988, Annals of Glaciology.

A Time-Dependent Simulation of the Ross Ice Shelf Flow (Abstract)

D. Macayeal, R. Thomas, 1984, Annals of Glaciology.