Skip to main content Accessibility help
×
Home

Basal melting at the Ekström Ice Shelf, Antarctica, estimated from mass flux divergence

  • Niklas Neckel (a1), Reinhard Drews (a1), Wolfgang Rack (a2) and Daniel Steinhage (a1)

Abstract

We characterize the basal mass balance of the Ekström Ice Shelf, Dronning Maud Land, Antarctica, using interferometrically derived surface velocities and ice thickness measurements from radio-echo sounding (RES). The surface velocities are based on data from European Remote-sensing Satellites-1 and -2 (ERS-1/2) during 1994–97. The ice thickness grid consists of 136 RES profiles acquired between 1996 and 2006. Mass fluxes are calculated along selected RES profiles where possible, to reduce uncertainties from ice thickness interpolation. Elsewhere large-scale mass fluxes are calculated using interpolated ice thickness data. Themass flux into the Ekström Ice Shelf from the main grounded drainage basins is estimated to be 3.19±0.4Gt a–1. The mass flux near the ice shelf front is 2.67±0.3Gt a–1. Assuming steady state, and based on the equation of continuity, we interpret the residual mass flux as a combined effect of snow accumulation and subglacial melting/refreezing. Using net snow accumulation rates from previous studies, we link the mass flux divergence in irregular-shaped polygons to processes beneath the ice shelf. The highest subglacial melt rates of ~1.1ma–1 are found near the grounding zone of two main inflow glaciers, and around the German station Neumayer III. The detection of unlikely refreezing in a small area ~15 km west of Neumayer III is attributed to both dataset inaccuracies and a (possibly past) violation of the steady-state assumption. In general, the method and input data allow mapping of the spatial distribution of basal melting and the results are in good agreement with several previous studies.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Basal melting at the Ekström Ice Shelf, Antarctica, estimated from mass flux divergence
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Basal melting at the Ekström Ice Shelf, Antarctica, estimated from mass flux divergence
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Basal melting at the Ekström Ice Shelf, Antarctica, estimated from mass flux divergence
      Available formats
      ×

Copyright

References

Hide All
Bamber, JL, Gomez-Dans, JL and Griggs, JA (2009) A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: data and methods. Cryosphere, 3(1), 101–111
Bindschadler, R and 17 others (2011) Getting around Antarctica: new high-resolution mappings of the grounded and freely-floating boundaries of the Antarctic ice sheet created for the International Polar Year. Cryosphere, 5(3), 569–588 (doi: 10.5194/tc-5-569-2011)
Blindow, N (1994) The central part of the Filchner–Ronne Ice Shelf, Antarctica: internal structures revealed by 40 MHz monopulse RES. Ann. Glaciol., 20, 365–371
Corr, HFJ, Jenkins, A, Nicholls, KW and Doake, CSM (2002) Precise measurement of changes in ice-shelf thickness by phase-sensitive radar to determine basal melt rates. Geophys. Res. Lett., 29(8), 1232 (doi: 10.1029/2001GL014618)
Drews, R, Rack, W, Wesche, C and Helm, V (2009) A spatially adjusted elevation model in Dronning Maud Land, Antarctica, based on differential SAR Interferometry, IEEE Trans. Geosci. Remote Sens., 47(8), 2501–2509
Fernandoy, F, Meyer, H, Oerter, H, Wilhelms, F, Graf, W and Schwander, J (2010) Temporal and spatial variation of stable-isotope ratios and accumulation rates in the hinterland of Neumayer station, East Antarctica. J. Glaciol., 56(198), 673–687 (doi: 10.3189/002214310793146296)
Fricker, HA, Popov, S, Allison, I and Young, N (2001) Distribution of marine ice beneath the Amery Ice Shelf. Geophys. Res. Lett., 28(11), 2241–2244 (doi: 10.1029/2000GL012461)
Gagliardini, O, Durand, G, Zwinger, T, Hindmarsh, RCA and LeMeur, E (2010) Coupling of ice-shelf melting and buttressing is a key process in ice-sheets dynamics. Geophys. Res. Lett., 37(14), L14501 (doi: 10.1029/2010GL043334)
Gille, ST (2008) Decadal-scale temperature trends in the southern hemisphere ocean. J. Climate, 21(18), 4749–4765 (doi: 10.1175/2008JCLI2131.1)
Griggs, JA and Bamber, JL (2011) Antarctic ice-shelf thickness from satellite radar altimetry. J. Glaciol., 57(203), 485–498 (doi: 10.3189/002214311796905659)
Haran, T, Bohlander, J, Scambos, T, Painter, T and Fahnestock, M (2006) MODIS mosaic of Antarctica (MOA) image map. National Snow and Ice Data Center, Boulder, CO. Digital media: http://nsidc.org/data/moa/
Hellmer, HH (2004) Impact of Antarctic ice shelf basal melting on sea ice and deep ocean properties. Geophys. Res. Lett., 31(10), L10307 (doi: 10.1029/2004GL019506)
Hinze, H (1990) Zum Einsatz von Satelliten-Positionierungsverfahren f ür glaziologische Aufgaben in der Antarktis. Wiss. Arbeit. Fachricht. Vermess. Univ. Hannover 163 (hdl:10013/epic.11967)
Holland, PR, Jenkins, A and Holland, DM (2008) The response of ice shelf basal melting to variations in ocean temperature. J. Climate, 21(11), 2558–2572 (doi: 10.1175/2007JCLI1909.1)
Humbert, A (2010) The temperature regime of Fimbulisen, Antarctica. Ann. Glaciol., 51(55), 56–64 (doi: 10.3189/172756410791392673)
Isaksson, E, Karlén, W, Gundestrup, N, Mayewski, P, Whitlow, S and Twickler, M (1996) A century of accumulation and temperature changes in Dronning Maud Land, Antarctica. J. Geophys. Res., 101(D3), 7085–7094 (doi: 10.1029/95JD03232)
Jenkins, A and Doake, CSM (1991) Ice–ocean interaction on Ronne Ice Shelf, Antarctica. J. Geophys. Res., 96(C1), 791–813 (doi: 10.1029/90JC01952)
Jenkins, A and 6 others (2010) Observations beneath Pine Island Glacier inWest Antarctica and implications for its retreat. Nature Geosci., 3(7), 468–472 (doi: 10.1038/ngeo890)
Joughin, I and Padman, L (2003) Melting and freezing beneath Filchner–Ronne Ice Shelf, Antarctica. Geophys. Res. Lett., 30(9), 1477–1480 (doi: 10.1029/2003GL016941)
Joughin, IR, Kwok, R and Fahnestock, MA (1998) Interferometric estimation of three-dimensional ice-flow using ascending and descending passes. IEEE Trans. Geosci. Remote Sens., 36(1), 25–37 (doi: 10.1109/36.655315)
Kipfstuhl, J (1991) Zur Entstehung von Unterwassereis und das Wachstum und die Energiebilanz des Meereises in der Atka Bucht, Antarktis. Ber. Polarforsch. 85. (hdl:10013/epic.10085.d001)
König-Langlo, G and Loose, B (2007) The meteorological observatory at Neumayer Stations (GvN and NM-II) Antarctica. Ber. Polarforsch/Rep. Pol. Res., 76(1–2), 25–38 (hdl:10013/epic.28566.d001)
Lambrecht, A, Nixdorf, U and Zürn, W (1995) Ablation rates under the Ekstr öm Ice Shelf deduced from different methods. FRISP Rep. 9, 50–56
Lambrecht, A, Sandhager, H, Vaughan, DG and Mayer, C (2007) New ice thickness maps of Filchner–Ronne Ice Shelf, Antarctica, with specific focus on grounding lines and marine ice. Antarct. Sci., 19(4), 521–532 (doi: 10.1017/S0954102007000661)
Ligtenberg, SRM, Helsen, MM and Van den Broeke, MR (2011) An improved semi-empirical model for the densification of Antarctic firn. Cryosphere, 5(4), 809–819 (doi: 10.5194/tc-5-809-2011)
Little, CM, Gnanadesikan, A and Oppenheimer, M (2009) How ice shelf morphology controls basal melting. J. Geophys. Res., 114(C12), C12007 (doi: 10.1029/2008JC005197)
Morlighem, M, Rignot, E, Seroussi, H, Larour, E, Ben Dhia, H and Aubry, D (2011) A mass conservation approach for mapping glacier ice thickness. Geophys. Res. Lett., 38(19), L19503 (doi: 10.1029/2011GL048659)
Müller, U, Sandhäger, H, Sievers, J and Blindow, N (2000) Glaciokinematic analysis of ERS-1/2 SAR data of the Antarctic ice shelf Ekstr ömisen and the adjoining inland ice sheet. Polarforschung, 67(1–2), 15–26
Nicolaus, M and Grosfeld, K (2002) Ice–ocean interaction underneath the Antarctic ice shelf Ekströmisen. Polarforschung, 72(1), 17–29 (hdl:10013/epic.21552.d001)
Nixdorf, U, Oerter, H and Miller, H (1994) First access to the ocean beneath Ekströmisen, Antarctica, by means of hot-water drilling. Ann. Glaciol., 20, 110–114
Nixdorf, U, Lambrecht, A and Steinhage, D (1997) Geophysical– glaciological studies in the grounding zone area of the Ekstr öm Ice Shelf (EIS). FRISP Rep. 11, 51–54
Payne, AJ, Vieli, A, Shepherd, A, Wingham, DJ and Rignot, E (2004) Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans. Geophys. Res. Lett., 31(23), L23401 (doi: 10.1029/2004GL021284)
Riedel, B and Vogel, D (1998) Geodätische Messungen an der Grounding Line des Ekström–Schelfeises. Ber. Polarforsch/Rep. Pol. Res. 267, 125–131
Rignot, E and Jacobs, SS (2002) Rapid bottom melting widespread near Antarctic ice sheet grounding lines. Science, 296(5575), 2020–2023 (doi: 10.1126/science.1070942)
Rignot, E and 11 others (2004) Improved estimation of the mass balance of the glaciers draining into the Amundsen Sea sector of West Antarctica from the CECS/NASA 2002 campaign. Ann. Glaciol., 39, 231–237 (doi: 10.3189/172756404781813916)
Rignot, E, Mouginot, J and Scheuchl, B (2011) Antarctic grounding line mapping from differential satellite radar interferometry. Geophys. Res. Lett., 38(10), L10504 (doi: 10.1029/2011GL047109)
Rotschky, G and 6 others (2007) A new surface accumulation map for western Dronning Maud Land, Antarctica, from interpolation of point measurements. J. Glaciol., 53(182), 385–398 (doi: 10.3189/002214307783258459)
Sandhäger, H (2000) Quantifizierung eisdynamischer und massenhaushaltsrelevanter Basisgr össen eines antarktischen Inlandeis-Schelfeis-Systems unter Einsatz eines numerischen Fliessmodells. (PhD thesis, Westfälische Wilhelms-Universität Münster)
Sandhäger, H and Blindow, N (2000) Surface elevation, ice thickness, and subglacial-bedrock topography of Ekström Ice Shelf (Antarctica) and its catchment area. Ann. Glaciol., 30, 61–68 (doi: 10.3189/172756400781820723)
Schlosser, E, Oerter, H and Graf, W (1999) Surface mass balance investigations on Ekströmisen, Antarctica, 1980–1996. Ber. Polarforsch/Rep. Pol. Res. 313
Seroussi, H and 6 others (2011) Ice flux divergence anomalies on 79north Glacier, Greenland. Geophys. Res. Lett., 38(9), L09501 (doi: 10.1029/2011GL047338)
Smedsrud, LH, Jenkin, A, Holland, DM and Nost, OA (2006) Modeling ocean processes below Fimbulisen, Antarctica. J. Geophys. Res., 111(C1), C01007 (doi: 10.1029/2005JC002915)
Steinhage, D, Nixdorf, U, Meyer, U and Miller, H (1999) New maps of the ice thickness and subglacial topography in Dronning Maud Land, Antarctica, determined by means of airborne radio-echo sounding. Ann. Glaciol., 29, 267–272 (doi: 10.3189/172756499781821409)
Steinhage, D, Nixdorf, U, Meyer, U and Miller, H (2001) Subglacial topography and internal structure of central, western Dronning Maud Land, Antarctica, determined from airborne radio echo sounding. J. Appl. Geophys., 47(3–4), 183–189 (doi: 10.1016/S0926-9851(01)00063-5)
Sykes, HJ, Murray, T and Luckman, A (2009) The location of the grounding zone of the Evans Ice Stream, Antarctica, investigated using SAR interferometry and modelling. Ann. Glaciol., 50(52), 35–40 (doi: 10.3189/172756409789624292)
Thyssen, F (1988) Special aspects of the central part of Filchner– Ronne Ice Shelf, Antarctica. Ann. Glaciol., 11, 173–179
Thyssen, F and Grosfeld, K (1988) Ekstr öm Ice Shelf, Antarctica. Ann. Glaciol., 11, 180–183
Wen, J, Wang, Y, Wang, W, Jezek, KC, Liu, H and Allison, I (2010) Basal melting and freezing under the Amery Ice Shelf, East Antarctica. J. Glaciol., 56(195), 81–90 (doi: 10.3189/002214310791190820)
Werner, LC, Wegmüller, U, Strozzi, T and Wiesmann, A (2000) Gamma SAR and interferometric processing software. In Proceedings of ERS–ENVISAT Symposium, 16–20 October 2000, Gothenburg, Sweden. European Space Agency, Noordwijk, 16–20 (ESA SP-461)
Wesche, C (2009) Evaluation and application of GPS and altimetry data over central Dronning Maud Land, Antarctica: annual elevation change, a digital elevation model, and surface flow velocity. (PhD thesis, University of Bremen)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed