Analysis of elevation discrepancies along the Lop Nur ear-shaped stripes observed using GLAS and DGPS data

Abstract

The Lop Nur is a dried-up salt lake lying in the eastern part of the Tarim Basin in China. The peculiar ear-shaped stripes in Lop Nur observed in satellite images have attracted the interest of investigators. It is believed that these stripes represent former lake shorelines, thus are valuable for studying the lake evolution. Owing to insufficient high-precision elevation data, the elevation along a given stripe was supposed to be constant. In this study, elevation data collected by the Geoscience Laser Altimeter System (GLAS) and the Differential Global Positioning System (DGPS) were carefully analysed. The combined topographic data for the ear-shaped region indicate that the elevations of the south shorelines are approximately 1 m higher than the north shorelines along the same stripe. We analyse the mechanisms of the phenomenon and suggest that the wind-driven water surface tilt at the time the ear-shaped stripes formed is the dominant one. The stripe profiles simulated by this mechanism show an excellent agreement with the measured stripe profiles.

Acknowledgements

The authors would like to thank NASA’s ICESAT Science Project and the NSIDC for distribution of the GLAS data. Thanks are due also to the US NGA’s distribution of the geoid model.

Funding

The work was supported by the Knowledge Innovation Programme from Chinese Academy of Sciences [grant number KZCX2-EW-320]; the Ministry of Science and Technology of China [grant number 2012FY111700]; the State Key Laboratory of Remote Sensing Science, Chinese Academy of Sciences [grant number Y1Y00201KZ]; the National Natural Science Foundation of China [grant number 41201346]; and the Institute of Remote Sensing and Applications, Chinese Academy of Sciences [grant numbers Y1S01200CX and Y3SG1900CX].