Title: The combined use of GPS and GRACE data to study glacial mass changes over Greenland
Speaker: Lin LIU (Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong)
Time: 10:00 a.m., Dec. 3, 2018 (Monday)
Location: Middle Conference Room, 3rd floor
Abstract:
Bedrock along the coast of Greenland is undergoing elastic deformation in response to present-day ice mass loss on and near the Greenland Ice Sheet. From decadal measurements from the network of Global Positioning System (GPS) stations mounted on bedrock, we observe strong trends (even acceleration) and prominent annual and inter-annual variability in time series of horizontal and vertical loading displacements. Using multiple GPS stations near Jakobshavn Isbr？ and Upernavik Isstr？m in western Greenland, we show how the annual and transient changes of the vertical displacements can be robustly quantified by applying the Multichannel Singular Spectral Analysis to the combination of GPS and Gravity Recovery and Climate Experiment (GRACE) data. Furthermore, by modeling elastic loading displacements due to surface mass balance (SMB) and glacial dynamics, we quantitatively interpret the geophysical sources of the observed variations. We find that transient variations in different periods could be caused by either SMB or glacial dynamics. Based on the loading theory and simulations using SMB models, we also propose multiple lines of explanations for the discrepancies between the GPS and GRACE observations over Greenland.
About the speaker:
Dr. Lin LIU is an Assistant Professor of the Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong. His research interests include Cryosphere Geophysics, Geodesy and Near Surface Geophysics and Radar remote sensing. For more information please go to the website: |
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