Decadal GPS-derived ice surface velocity along the transect from Zhongshan Station to and around Dome Argus, East Antarctica, 2005–16

Yang Yuande,Ke Hao,Ding Minghu,Ai Songtao,Wang Lianzhong,Jin Bo,Wang Zemin,Li Fei,Sun Bo

doi:10.1017/aog.2018.3

Abstract

ABSTRACTUsing repeat GPS measurements during 2005–16, we calculated and updated two-dimensional high-resolution decadal ice surface velocity estimates along the traverse route from Zhongshan Station to and around Dome Argus, East Antarctica. Along the 71 sites of the transect, the magnitudes of ice velocity increased from near 0 in Dome Argus to 1, 10 and ~100 m a−1 at the sites DT416, DT333 and LT980, respectively. The comparison between GPS and interferometric synthetic aperture radar (InSAR) derived results agree well when the magnitude of the ice surface velocities is faster than 5 m a−1, and disagree for slower flow velocities. A scale value 1.15 and 0.12 can be applied to InSAR derived results over this region with ice surface velocity larger and <5 m a−1, respectively. We attributed the cause of the discrepancy to the insensitivity of InSAR to the magnitude of low ice surface velocities, thus confirming the importance of GPS fieldwork-based ground truth high-resolution ice velocity estimates to constrain ice-sheet dynamics.

Highlights

IntroductionThe mass balance of the Antarctic ice sheet is an important climatic variable since it has an important impact on global sea-level rise (Meier, 1993; Alley and others, 2005), based on the fact that it is the largest freshwater ice reservoir on Earth
Ice sheets play a major role in global climate change and sealevel rise
The largest velocity speed difference located at site DT063 was 0.9 m a−1, where the difference was ∼10% of the velocity speed 9 m a−1

Summary

Introduction

The mass balance of the Antarctic ice sheet is an important climatic variable since it has an important impact on global sea-level rise (Meier, 1993; Alley and others, 2005), based on the fact that it is the largest freshwater ice reservoir on Earth. Since the 21st CHINARE in 2005, meteorological measurements from automatic weather stations, ice-sheet thickness and bed topography, surface mass balance (SMB)/snow accumulation, surface topography and velocity field have been studied (Hou and others, 2007; Zhang and others, 2007; Xiao and others, 2008; Cheng and others, 2009; Sun and others, 2009; Cui and others, 2010; Ma and others, 2010; Bell and others, 2011; Ding and others, 2011, 2016; Yang and others, 2014)

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Conclusion