ANTARCTIC ICE SHEET SURFACE MASS BALANCE ESTIMATES FROM 2003 TO 2015 USING ICESAT AND CRYOSAT-2 DATA

Historical velocity maps of the Antarctic ice sheet are valuable for long-term ice flow dynamics analysis. We developed an innovative method for correcting overestimations existing in historical velocity maps. The method is validated rigorously using high-quality Landsat 8 images and then successfully applied to historical velocity maps. The historical change signatures are preserved and can be used for assessing the impact of long-term global climate changes on the ice sheet.

No subglacial lakes have been reported in Princess Elizabeth Land (PEL), East Antarctica. In this study, thanks to a new suite of airborne geophysical observations in PEL, including RES and gravity data collected during the Chinese National Antarctic Research Expedition, we detected a large subglacial lake of ~45 km in length, ~11 km in width, and ~250 m in depth. These findings will help us understand ice sheet stability in the PEL region.

We present the results of an assessment of ICESat-2 surface elevations along the 520 km CHINARE route in East Antarctica. The assessment was performed based on coordinated multi-sensor observations from a global navigation satellite system, corner cube retroreflectors, retroreflective target sheets, and UAVs. The validation results demonstrate that ICESat-2 elevations are accurate to 1.5–2.5 cm and can potentially overcome the uncertainties in the estimation of mass balance in East Antarctica.

Fracturing in the RFIS was slightly increased, particularly at its front, from 2003 to 2015. They do not seem to suggest an immediate significant impact on the stability of the shelf. However, with the rapid changes and 3D measurements of Rifts 1 and 2, the most active activities occurred at the front of the FIS from 2001 to 2016. A potential upcoming major calving event in FIS is estimated to occur in 2051. The stability of the ice shelf, particularly Rifts 1 and 2, should be closely monitored.