Abstract
We compare satellite altimetry from the Ice, Cloud, and Land Elevation Satellite (ICESat, 2003–2007) to older topographic maps and digital elevation models (1965–1990) to calculate long‐term elevation changes of glaciers on the Svalbard Archipelago. Results indicate significant thinning at most glacier fronts with either slight thinning or thickening in the accumulation areas, except for glaciers that surged which show thickening in the ablation area and thinning in the accumulation areas. The most negative geodetic balances occur in the south and on glaciers that have surged, while the least negative balances occur in the northeast and on glaciers in the quiescent phase of a surge cycle. Geodetic balances are related to latitude and to the dynamical behavior of the glacier. The average volume change rate over the past 40 years for Svalbard, excluding Austfonna and Kvitøya is estimated to be −9.71 ± 0.55 km3 yr−1 or −0.36 ± 0.02 m yr−1 w. equivalent, for an annual contribution to global sea level rise of 0.026 mm yr−1 sea level equivalent.
Highlights
Glaciers, ice-caps and ice sheets together cover ≈14.5 million km2 of the Earth’s surface and have a potential to raise sea level1 up to ≈64 m (Lemke et al, 2007)
Observations of glaciers have become more prevalent in the past 50-75 years especially due to the advanced remote sensing techniques that are creating a higher spatially and temporally sampled data set from satellites
The dynamic response of a glacier to a shift in climate is not immediate but is subjected to a lag that may be on the order of decades to centuries (Johannesson et al, 1989)
Summary
Ice-caps and ice sheets together cover ≈14.5 million km of the Earth’s surface and have a potential to raise sea level up to ≈64 m (Lemke et al, 2007). Monitoring changes of glaciers, ice-caps and ice sheets is important in determining the past and present day contribution to sea level fluctuation and to better characterize the present day changes in relation to climatic fluctuations This mass balance may be divided into three components: the surface and basal mass balance and the mass loss due to calving icebergs. Monitoring glacier changes directly from the ground include measurements of the surface mass balance, velocity and/or elevation and terminus changes. The third is the newly released ASTER GDEM based upon a composition of automatically generated DEMs from Advanced Spaceborne Emission and Reflection radiometer (ASTER) stereo scenes acquired 15 from 2000–present (METI/NASA/USGS, 2009) Many of these products contain errors and biases resulting from sensor instabilities, limitations of the techniques, bad surveying conditions on the ground and various types of post-processing artifacts. The errors occur at a range of scales that directly affect measurement precision and increases the significance level an elevation change requires for adequate detection through eleva tion differencing
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.