Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

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 datacoverage 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 72m 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.

Bamber, J. L., Baldwin, D. J., and Gogineni, S. P.: A new bedrock
and surface elevation dataset for modelling the Greenland ice
sheet, Ann. Glaciol., 37, 351-356, 2003.
Bamber, J. L., Gomez-Dans, J. L., and Griggs, J. A.: A new 1 km
digital elevation model of the Antarctic derived from combined
satellite radar and laser data –Part 1: Data and methods, The
Cryosphere, 3, 101–111, doi:10.5194/tc-3-101-2009, 2009a.
Bamber, J. L., Riva, R. E. M., Vermeersen, B. L. A., and LeBrocq,
A. M.: Reassessment of the Potential Sea-Level Rise from a Collapse
of the West Antarctic Ice Sheet, Science, 324, 901–903,
doi:10.1126/science.1169335, 2009b.
Beaman, R.J., O’Brien, P. E., Post, A. L., and De Santis, L. : A
new high-resolution bathymetry model for the Terre Ad´elie and
George V continental margin, East Antarctica, Antarctic Sci., 23,
95–103, doi:10.1017/S095410201000074X, 2010. Bell, R. E., Ferraccioli, F., Creyts, T. T., Braaten, D., Corr, H., Das,
I., Damaske, D., Frearson, N., Jordan, T., Rose, K., Studinger,
M., and Wolovick, M.: Widespread Persistent Thickening of the
East Antarctic Ice Sheet by Freezing from the Base, Science, 331,
1592–1595, doi:10.1126/science.1200109, 2011.
Bentley, C. R.: The structure of Antarctica and its ice cover, in:
Research in Geophysics Vol. 2, Solid Earth and Interface Phenomena,
edited by: Odishaw, H., MIT Press, Cambridge, Mass.,
335–389, 1964.
Bindschadler, R., Vornberger, P., Fleming, A., Fox, A., Mullins, J.
L., Binnie, D., Paulsen, S. J., Granneman, B., and Gorodetzky,
D.: The Landsat Image Mosaic of Antarctica, Remote Sens. Environ.,
112, 4214–4226, 2008.
Bingham, R. G., Ferraccioli, F., King, E. C., Larter, R. D., Pritchard,
H. D., Smith, A. M., and Vaughan, D. G.: Inland thinning ofWest
Antarctic Ice Sheet steered along subglacial rifts, Nature, 487,
468–471, doi:10.1038/nature11292, 2012.
Bohlander, J. and Scambos, T.: Antarctic coastlines and grounding
line derived from MODIS Mosaic of Antarctica (MOA), National
Snow and Ice Data Center, Boulder, CO, USA, 2007.
Bolmer, S. T.: A note on the development of the bathymetry of the
continental margin west of the Antarctic Peninsula from 658 to
718S and 658 to 788W. Deep-Sea Res. Pt. II, 55, 271–276, 2008
Brenner, A. C., DiMarzio, J. R., and Zwally, H. J.: Precision and
accuracy of satellite radar and laser altimeter data over the continental
ice sheets, IEEE Trans. Geosci. Remote Sensing, 45, 321–
331, doi:10.1109/TGRS.2006.887172, 2007.
Cook, A. J., Murray, T., Luckman, A., Vaughan, D. G., and Barrand,
N. E.: A new 100-m Digital Elevation Model of the
Antarctic Peninsula derived from ASTER Global DEM: methods
and accuracy assessment, Earth Syst. Sci. Data, 4, 129–142,
doi:10.5194/essd-4-129-2012, 2012.
DiMarzio, J., Brenner, A., Schutz, R., Shuman, C. A., and Zwally,
H. J.: GLAS/ICESat 500 m laser altimetry digital elevation
model of Antarctica: Digital media, National Snow and Ice Data
Center, Boulder, CO, USA, 2007.
Drewry, D. J. and Jordan, S. R.: The bedrock surface of Antarctica,
Scott Polar Research Institute, Cambridge, 1983.
Drewry, D. J., Jordan, S. R., and Jankowski, E.: Measured propoerties
of the Antarctic Ice Sheet: Surface configuration, ice thickness,
volume and bedrock characteristics, Ann. Glaciol., 3, 83–
91, 1982.
Drewry, D. J., Morris, E. M., Robin, G. D. Q., and Weller,
G.: The Response of Large Ice Sheets to Climatic Change
[and Discussion], Philos. T. Roy. Soc. B, 338, 235–242,
doi:10.1098/rstb.1992.0143, 1992.
Eagles, G., Larter, R. D., Gohl, K., and Vaughan, A. P. M.: West
Antarctic Rift System in the Antarctic Peninsula, Geophys. Res.
Lett., 36, L21305, doi:10.1029/2009gl040721, 2009.
Ferraccioli, F., Armadillo, E., Jordan, T., Bozzo, E., and Corr, H.:
Aeromagnetic exploration over the East Antarctic Ice Sheet: A
new view of the Wilkes Subglacial Basin, Tectonophysics, 478,
62–77, doi:10.1016/j.tecto.2009.03.013, 2009.
Ferraccioli, F., Finn, C. A., Jordan, T. A., Bell, R. E., Anderson,
L. M., and Damaske, D.: East Antarctic rifting triggers
uplift of the Gamburtsev Mountains, Nature, 479, 388–392,
doi:10.1038/nature10566, 2011.
Forste, C., Schmidt, R., Stubenvoll, R., Flechtner, F., Meyer, U.,
Konig, R., Neumayer, H., Biancale, R., Lemoine, J. M., Bruinsma, S., Loyer, S., Barthelmes, F., and Esselborn, S.: The Geo-
ForschungsZentrum Potsdam/Groupe de Recherche de Geodesie
Spatiale satellite-only and combined gravity field models:
EIGEN-GL04S1 and EIGEN-GL04C, J. Geodesy, 82, 331–346,
doi:10.1007/s00190-007-0183-8, 2008.
Graham, A. G. C., Fretwell, P. T., Larer, R. D., Hodgson, D. A.,
Wilson, C. K., Tate, A. J., and Morris, P.: New bathymetric compilation
highlights extensive paleo-ice sheet drainage on the continental
shelf South Georgia, sub-Antarctica, Geochem. Geophy.
Geosy., 9, Q07011, doi:10.1029/2008GC001993, 2009.
Graham, A. G. C., Nitsche, F. O., and Larter, R. D.: An improved
bathymetry compilation for the Bellingshausen Sea, Antarctica,
to inform ice-sheet and ocean models, The Cryosphere, 5, 95–
106, doi:10.5194/tc-5-95-2011, 2011.
Griggs, J. A. and Bamber, J. L.: Antarctic ice-shelf thickness from
satellite radar altimetry, J. Glaciol., 57, 485–498, 2011.
Haran, T., Bohlander, J., Scambos, T., Fahnestock, M., and compilers:
MODIS mosaic of Antarctica (MOA) image map: Digital
media, National Snow and Ice Data Center, Boulder, CO, USA,
2005.
Holt, J.W., Blankenship, D. D., Morse, D. L., Young, D. A., Peters,
M. E., Kempf, S. D., Richter, T. G., Vaughan, D. G., and Corr, H.
F. J.: New boundary conditions for the West Antarctic ice sheet:
subglacial topography beneath Thwaites and Smith glaciers,
Geophys. Res. Lett., 33, L09502, doi:10.1029/2005GL025561,
2006.
Hutchinson, M. F.: Calculation of hydrologically sound digital elevation
models, Third International Symposium on Spatial Data
Handling, Sydney, 1988.
Hutchinson, M. F.: A new procedure for gridding elevation and
stream line data with automatic removal of spurious pits, J. Hydrol.,
106, 211–232, 1989.
Jakobsson, M., Cherkis, N. Z., Woodward, J., MacNab, R., and
Coakley, B.: New grid of Arctic bathymetry aids scientists and
mapmakers, EOS Trans. AGU, 81, 89–96, 2000.
Jamieson, S. S. R., Hulton, N. R. J., Sugden, D. E., Payne, A. J., and
Taylor, J.: Cenozoic landscape evolution of the Lambert basin,
East Antarctica: the relative role of rivers and ice sheets, Glob.
Planet. Change, 45, 35–49, 2005.
Jenkins, A. and Holland, D.: Melting of floating ice
and sea level rise, Geophys. Res. Lett., 34, L16609,
doi:10.1029/2007gl030784, 2007.
Kapitsa, A. P.: New data on ice thickness in the central regions
of Antarctica, Soviet Antarctic Expedition Bulletin, Information
Bulletin, 2, 247–250, 1964.
King, E. C., Hindmarsh, R. C. A., and Stokes, C. R.: Formation of
mega-scale glacial lineations observed beneath a West Antarctic
ice stream, Nat. Geosci., 2, 585–588, doi:10.1038/NGEO581,
2009.
Korona, J., Berthier, E., Bernard, M., Remy, F., and Thouvenot,
E.: SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference
Images and Topographies during the fourth International
Polar Year (2007–2009), ISPRS-J. Photogramm., 64, 204–212,
doi:10.1016/j.isprsjprs.2008.10.005, 2009.
Le Brocq, A. M., Hubbard, A., Bentley, M. J., and Bamber,
J. L.: Subglacial topography inferred from ice surface terrain
analysis reveals a large un-surveyed basin below sea
level in East Antarctica, Geophys. Res. Lett., 35,L16503,
doi:10.1029/2008gl034728, 2008a. Le Brocq, A. M., Hubbard, A., Bentley, M. J., and Bamber,
J. L.: Subglacial topography inferred from ice surface terrain
analysis reveals a large un-surveyed basin below sea
level in East Antarctica, Geophys. Res. Lett., 35, L16503,
doi:10.1029/2008gl034728, 2008b.
Le Brocq, A. M., Payne, A. J., and Vieli, A.: An improved
Antarctic dataset for high resolution numerical ice sheet
models (ALBMAP v1), Earth Syst. Sci. Data, 2, 247–260,
doi:10.5194/essd-2-247-2010, 2010.
Leuschen, C. and Allen, C.: IceBridge MCoRDS L2 Ice Thickness,
2009–2011: Digital media, NASA Distributed Active Archive
Center at the National Snow and Ice Data Center, Boulder, CO,
USA, 2012.
Ligtenberg, S. R. M., Helsen, M. M., and van den Broeke, M. R.: An
improved semi-empirical model for the densification of Antarctic
firn, The Cryosphere, 5, 809–819, doi:10.5194/tc-5-809-2011,
2011.
Liu, H. X., Jezek, K. C., and Li, B.: Development of Antarctic DEM
by integrating cartographic and remotely sensed data: A GISbased
approach., J. Geophys. Res., 104, 23199–23213, 1999.
Luyendyk, B. P., Wilson, D. S., and Siddoway, C.S.: Eastern margin
of the Ross Sea rift in western Marie Byrd Land, Antarctica:
Crustal structure and tectonic development, Geochem. Geophy.
Geosy., 4, 1090, doi:10.1029/2002GC000462, 2003.
Lythe, M., Vaughan, D. G., and BEDMAP Consortium: BEDMAP
– Bed topography of the Antarctic, BAS Misc., 9 Edn.,
SCAR/BAS, Cambridge, 2000.
Lythe, M., Vaughan, D. G., and The BEDMAP Consortium:
BEDMAP: a new ice thickness and subglacial topographic model
of Antarctica, J. Geophys. Res., 106, 11335–11352, 2001.
Morlighem, M., Rignot, E., Seroussi, H., Larour, E., Ben Dhia,
H., and Aubry, D.: A mass conservation approach for mapping
glacier ice thickness, Geophys. Res. Lett., 38, L19503,
doi:10.1029/2011gl048659, 2011.
Nitsche, F. O., Jacobs, S., Larter, R., and Gohl, K.: Bathymetry
of the Amundsen Sea continental shelf: implications for geology,
oceanography, and glaciology, Geochem. Geophy. Geosy.,
8, Q10009, doi:10.1029/2007GC001694, 2007.
Pritchard, H. D., Arthern, R. J., Vaughan, D. G., and Edwards, L.
A.: Extensive dynamic thinning at the margins of the Greenland
and Antarctic ice sheets, Nature, 461, 971–975, 2009.
Pritchard, H. D., Ligtenberg, S. R. M., Fricker, H. A., Vaughan, D.
G., van den Broeke, M., and Padman, L.: Antarctic ice loss driven
by ice-shelf melt, Nature, 484, 502–505, 2012.
Rebesco, M., Camerlenghi, A., Geletti, R., and Canals, M.: Margin
architecture reveals the transition to the modern Antarctic ice
sheet ca. 3 Ma., Geology, 34, 301–304, 2006.
Riedel, S., Jokat, W., and Steinhage, D.: Mapping tectonic
provinces with airborne gravity and radar data in Dronning
Maud Land, East Antarctica, Geophys. J. Int., 189, 414–427,
doi:10.1111/j.1365-246X.2012.05363.x, 2012.
Rignot, E., Mouginot, J., and Scheuchl, B.: Antarctic grounding line
mapping from differential satellite radar interferometry, Geophys.
Res. Lett., 38, L10504, doi:10.1029/2011gl047109, 2011.
Roberts, J. L., Warner, R. C., Young, D., Wright, A., van Ommen,
T. D., Blankenship, D. D., Siegert, M., Young, N.W., Tabacco, I.
E., Forieri, A., Passerini, A., Zirizzotti, A., and Frezzotti, M.: Refined
broad-scale sub-glacial morphology of Aurora Subglacial
Basin, East Antarctica derived by an ice-dynamics-based inter-polation scheme, The Cryosphere, 5, 551—560, doi:10.5194/tc-
5-551-2011, 2011.
Ross, N., Bingham, R. G., Corr, H. F. J., Ferraccioli, F., Jordan, T.
A., Le Brocq, A., Rippin, D. M., Young, D., Blankenship, D. D.,
and Siegert, M. J.: Steep reverse bed slope at the grounding line
of the Weddell Sea sector in West Antarctica, Nat. Geosci., 5,
393–396, 2012.
Shabtaie, S. and Bentley, C. R.: West Antarctic Ice Streams draining
into the Ross Ice Shelf: configuration and mass balance, J.
Geophys. Res., 92, 1311–1336, 1987.
Shepherd, A., Wingham, D., Wallis, D., Giles, K., Laxon, S.,
and Sundal, A. V.: Recent loss of floating ice and the consequent
sea level contribution, Geophys. Res. Let., 37, L13503,
doi:10.1029/2010gl042496, 2010.
Smith, A. M., Murray, T., Nicholls, K. W., Makinson, K., Adalgeirsdottir,
G., Behar, A. E., and Vaughan, D. G.: Rapid erosion,
drumlin formation and changing hydrology beneath Antarctic ice
stream, Geology, 35, 127–130, 2007.
Smith, W. H. F. and Sandwell, D. T.: Global sea floor topography
from satellite altimetry and ship depth soundings, Science, 277,
1956–1962, doi:10.1126/science.277.5334.1956, 1997.
Snyder, J. P.: Map Projections: AWorking Manual, USGS, 385 pp.,
1987.
Spada, G., Bamber, J. L., and Hurkmans, R.: The gravitationally
consistent sea-level fingerprint of future terrestrial ice loss, Geophys.
Res. Lett., in press, doi:10.1029/2012GL053000, 2013.
Tapley, B. D., Bettadpur, S., Watkins, M., and Reigber,
C.: The gravity recovery and climate experiment: Mission
overview and early results, Geophys. Res. Lett., 31, L09607,
doi:10.1029/2004gl019920, 2004. Timmermann, R., Le Brocq, A., Deen, T., Domack, E., Dutrieux,
P., Galton-Fenzi, B., Hellmer, H., Humbert, A., Jansen, D., Jenkins,
A., Lambrecht, A., Makinson, K., Niederjasper, F., Nitsche,
F., Nøst, O. A., Smedsrud, L. H., and Smith, W. H. F.: A consistent
data set of Antarctic ice sheet topography, cavity geometry,
and global bathymetry, Earth Syst. Sci. Data, 2, 261–273,
doi:10.5194/essd-2-261-2010, 2010.
Vaughan, D. G. and Bamber, J. L.: Identifying areas of low-profile
ice and outcrop damming in the Antarctic ice sheet by ERS-1
satellite altimetry, Ann. Glaciol., 27, 1–6, 1998.
Vaughan, D. G., Corr, H. F. J., Ferraccioli, F., Frearson, N., O’Hare,
A., Mach, D., Holt, J. W., Blankenship, D. D., Morse, D., and
Young, D. A.: New boundary conditions for the West Antarctic
ice sheet: Subglacial topography beneath Pine Island Glacier,
Geophys. Res. Lett., 33, L09501, doi:10.1029/2005GL025588,
2006.
Vaughan, D. G., Corr, H. F. J., Pritchard, H., Shepherd, A., and
Smith, A. M.: Flow-switching and water-piracy between Rutford
Ice Stream and Carlson Inlet, West Antarctica, J. Glaciol., 54,
41–48, 2008.
Vaughan, D. G., Barnes, D. K. A., Fretwell, P. T., and Bingham, R.
G.: Potential open seaways across West Antarctica, Geochem.
Geophy. Geosy., 12, Q10004, doi:10.1029/2011GC003688,
2011.
Welch, B. C. and Jacobel, R.W.: Analysis of deep-penetrating radar
surveys of West Antarctica, US-ITASE 2001, Geophys. Res.
Lett., 30, 1444 doi:10.1029/2003GL017210, 2003.
Wu, X. L. and Jezek, K. G.: Antarctic ice-sheet balance velocities
from merged point and vector data, J. Glaciol., 50, 219–230,
2004.