Mapping the Antarctic Grounding Zone from ICESat-2 Laser Altimetry

• Main Authors: Li, Tian, Dawson, Geoffrey J., Chuter, Stephen J., Bamber, Jonathan L.
• Format: Text
• Language: English
• Published: 2020
• Subjects: Antarctic; Antarctic Peninsula; The Antarctic; Antarc*; Ice Sheet; Ice Shelf
• Online Access: https://doi.org/10.5194/tc-2020-105; https://tc.copernicus.org/preprints/tc-2020-105/

We present the results of mapping the grounding zone of the Antarctic Ice Sheet using laser altimetry from the ICESat-2 satellite, based on a combination of repeat track data and crossover analysis of ascending and descending tracks. We use a new automated method to provide estimates for both the landward limit of ice flexure and the inshore limit of hydrostatic equilibrium by detecting the ocean tidal signals, and is demonstrated on the Larsen C Ice Shelf in the Antarctic Peninsula. The results show a 2 times increase in number of observations of the grounding line location compared to ICESat-1, as well as improved precision. The mean absolute separation and the standard deviation between our ICESat-2 derived grounding line and DInSAR grounding line product are 0.29 km and 0.31 km, respectively. The beam pair structure of ICESat-2 enables us to derive the grounding zone features from a minimum of two repeat cycles. Our results demonstrate that ICESat-2 can provide high precision and density observations of grounding line in both space and time. This new method can improve the efficiency of grounding zone calculation and can be applied to other regions of the Antarctic Ice Sheet.