SPOT5-HRS digital elevation models and the monitoring of glacier elevation changes in North-West Canada and South-East Alaska

Abstract Monitoring the response of land ice to climate change requires accurate and repeatable topographic surveys. The SPOT5-HRS (High Resolution Stereoscopic) instrument covers up to 120 km by 600 km in a single pass and has the potential to accurately map the poorly known topography of most glaciers and ice caps. The acquisition of a large HRS archive over ice-covered regions is planned by the French Space Agency (CNES) and Spotimage, France during the 2007–2008 International Polar Year (IPY). Here, we report on the accuracy and value of HRS digital elevation model (DEM) over ice and snow surfaces. A DEM is generated by combining tools available from CNES with the PCI Orthoengine SE software, using HRS images acquired in May 2004 over South-East Alaska (USA) and northern British Columbia (Canada). The DEM is evaluated through comparison with shuttle radar topographic mission (SRTM) DEM and ICESAT data, on and around the glaciers. A horizontal shift of 50 m is found between the HRS and SRTM DEMs and is attributed to errors in the SRTM DEM. Over ice-free areas, HRS elevations are 7 m higher than those of SRTM, with a standard deviation of ± 25 m for the difference between the two DEMs. The 7-m difference is partly attributed to the differential penetration of the electromagnetic waves (visible for HRS; microwave for SRTM) in snow and vegetation. We also report on the application of sequential DEMs (SRTM DEM in February 2000 and HRS DEM in May 2004) for the monitoring of glacier elevation changes. We map the topographic changes induced by a surge of one tributary of Ferris Glacier. Maximum surface lowering of 42 (± 10) m and rising of 77 (± 10) m are observed in the 4 years time interval. Thinning rates up to 10 (± 2.5) m/yr are observed at low altitudes and confirm the ongoing wastage of glaciers in South-East Alaska.

[1]  D. Harding,et al.  ICESat validation of SRTM C‐band digital elevation models , 2004 .

[2]  Thierry Toutin,et al.  Comparison of stereo-extracted DTM from different high-resolution sensors: SPOT-5, EROS-a, IKONOS-II, and QuickBird , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[3]  G. Clarke,et al.  Glaciers of the coast mountains , 2002 .

[4]  Bruce F. Molnia,et al.  Late nineteenth to early twenty-first century behavior of Alaskan glaciers as indicators of changing regional climate , 2007 .

[5]  A. Roth,et al.  The shuttle radar topography mission—a new class of digital elevation models acquired by spaceborne radar , 2003 .

[6]  Bryan L. Isacks,et al.  Interannual variations of snowmelt and refreeze timing on southeast-Alaskan icefields, U.S.A. , 2003, Journal of Glaciology.

[7]  T. Toutin,et al.  Stereo RADARSAT Data for Canopy Height in Brazilian Forests , 2000 .

[8]  E. Rodríguez,et al.  A Global Assessment of the SRTM Performance , 2006 .

[9]  O. Eisen,et al.  The surges of Variegated Glacier and their connection to climate and mass balance , 2001 .

[10]  M. Pelto,et al.  Mass Balance of the Taku Glacier, Alaska from 1946 to 1986 , 1990 .

[11]  P. Chevallier,et al.  Remote sensing estimates of glacier mass balances in the Himachal Pradesh (Western Himalaya, India) , 2007 .

[12]  John D. Vona,et al.  Vegetation height estimation from Shuttle Radar Topography Mission and National Elevation Datasets , 2004 .

[13]  Thierry Toutin,et al.  ASTER DEMs for geomatic and geoscientific applications: a review , 2008 .

[14]  T. Toutin.  Generation of DSMs from SPOT-5 in-track HRS and across-track HRG stereo data using spatiotriangulation and autocalibration , 2006 .

[15]  R. Armstrong,et al.  The Physics of Glaciers , 1981 .

[16]  B. Menounos,et al.  Recent volume loss of British Columbian glaciers, Canada , 2007 .

[17]  Y. Arnaud,et al.  Biases of SRTM in high‐mountain areas: Implications for the monitoring of glacier volume changes , 2006 .

[18]  Thierry Toutin,et al.  Three-dimensional topographic mapping with ASTER stereo data in rugged topography , 2002, IEEE Trans. Geosci. Remote. Sens..

[19]  Y. Arnaud,et al.  Recent rapid thinning of the “Mer de Glace” glacier derived from satellite optical images , 2004 .

[20]  T. Toutin,et al.  Comparison of automated digital elevation model extraction results using along-track ASTER and across-track SPOT stereo images , 2002 .

[21]  J. Dall,et al.  Volume changes of Vatnajökull ice cap, Iceland, due to surface mass balance, ice flow, and subglacial melting at geothermal areas , 2005 .

[22]  W. Krabill,et al.  Penetration depth of interferometric synthetic‐aperture radar signals in snow and ice , 2001, Geophysical Research Letters.

[23]  Frederique Remy,et al.  Estimating terrestrial snow depth with the TOPEX-Poseidon altimeter and radiometer , 2002, IEEE Trans. Geosci. Remote. Sens..

[24]  Y. Weidmann,et al.  Remote sensing of glacier- and permafrost-related hazards in high mountains: an overview , 2005 .

[25]  Helgi Björnsson,et al.  Hydrological characteristics of the drainage system beneath a surging glacier , 1998, Nature.

[26]  David B. Bahr,et al.  The Physics of Glaciers, 3rd Edition , 1995 .

[27]  A. Ohmura,et al.  Mass balance of glaciers and ice caps: Consensus estimates for 1961–2004 , 2006 .

[28]  L. Stearns,et al.  Rapid volume loss from two East Greenland outlet glaciers quantified using repeat stereo satellite imagery , 2007 .

[29]  Jeffrey S. Kargel,et al.  Multispectral imaging contributions to global land ice measurements from space , 2005 .

[30]  Garry K. C. Clarke,et al.  Glaciers of the St. Elias mountains , 2002 .

[31]  A. K77b,et al.  Combination of SRTM 3 and repeat ASTER data for deriving alpine glacier flow velocities in the Bhutan Himalaya , 2005 .

[32]  A. Arendt,et al.  Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level , 2002, Science.

[33]  Hiroshi Murakami,et al.  ASTER as a source for topographic data in the late 1990s , 1998, IEEE Trans. Geosci. Remote. Sens..

[34]  H. Zwally,et al.  Overview of ICESat's Laser Measurements of Polar Ice, Atmosphere, Ocean, and Land , 2002 .

[35]  J. G. Ferrigno,et al.  SATELLITE IMAGE ATLAS OF GLACIERS OF THE WORLD: NORTH AMERICA. Richard S. Williams Jr and Jane G. Ferrigno (Editors). 2002. Washington, DC: US Government Printing Office (US Geological Survey Professional Paper 1386-J). xii+405 p, illustrated, soft cover. ISBN 0-607-98290-X. , 2004, Polar Record.

[36]  Kurt L. Feigl,et al.  The level of the Grímsvötn subglacial lake, Vatnajökull, Iceland, monitored with SPOT5 images , 2006 .

[37]  S. O’Neel,et al.  Twentieth century thinning of Mendenhall Glacier, Alaska, and its relationship to climate, lake calving, and glacier run-off , 2003 .

[38]  A. Cazenave.  How Fast Are the Ice Sheets Melting? , 2006, Science.

[39]  T. Toutin,et al.  Elevation modelling from satellite visible and infrared (VIR) data , 2001 .

[40]  Arzhan B. Surazakov,et al.  Estimating volume change of mountain glaciers using SRTM and map-based topographic data , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[41]  O. Eisen,et al.  The surges of Variegated Glacier, Alaska, U.S.A., and their connection to climate and mass balance , 2001 .

[42]  Thierry Toutin,et al.  State-of-the-art of elevation extraction from satellite SAR data , 2000 .

[43]  T. Scambos,et al.  Rapid Changes in Ice Discharge from Greenland Outlet Glaciers , 2007, Science.

[44]  Richard M. Goldstein,et al.  Studies of multibaseline spaceborne interferometric synthetic aperture radars , 1990 .

[45]  Mark F. Meier,et al.  GLACIERS AND THE CHANGING EARTH SYSTEM: A 2004 SNAPSHOT , 2010 .

[46]  Scott B. Luthcke,et al.  Ice elevations and surface change on the Malaspina Glacier, Alaska , 2005 .

[47]  Paul E. Geissler,et al.  Glacier Changes in Southeast Alaska and Northwest British Columbia and Contribution to Sea Level Rise , 2007 .

[48]  Alison Fell,et al.  Mer de Glace , 1991 .

[49]  Bernd Etzelmüller,et al.  On the Quantification of Surface Changes using Grid‐based Digital Elevation Models (DEMs) , 2000, Trans. GIS.

[50]  A. Kääb.  Combination of SRTM3 and repeat ASTER data for deriving alpine glacier flow velocities in the Bhutan Himalaya , 2005 .

[51]  A. Bouillon,et al.  SPOT 5 HRS geometric performances: Using block adjustment as a key issue to improve quality of DEM generation , 2006 .