G33B-1139
Study of the Northern Qinghai-Tibetan Plateau Permafrost Active Layer Depth Rate Using Satellite Geodetic Observations
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Xiaoli Su1, C.K. Shum2, Yuanyuan Jia1, Jin Woo Kim3 and Chung-Yen Kuo4, (1)Ohio State University Main Campus, Division of Geodetic Science, School of Earth Sciences, Columbus, OH, United States, (2)Ohio State University, Columbus, OH, United States, (3)Southern Methodist University, Dallas, TX, United States, (4)National Cheng Kung University, Geomatics, Taiwan, Taiwan
Abstract:
The Tibetan Plateau is the world’s largest and the highest plateau with distinct and competing surface and subsurface processes. It is the Third Pole and the World Water Tower, owing to its vast ice reservoir with the largest number of glaciers in the world, and covered by a large (1.3 to 1.6 million km2) layer of discontinuous and sporadic alpine permafrost. The thawing over Tibetan Plateau permafrost regions is thought to be more severe compared with other high latitude permafrost regions by the fact that the permafrost is warm. During the past few decades, 82% of Tibetan Plateau glaciers have retreated and 10% permafrost has degraded. The overall mean active layer depth (ALD) rate increase over the Plateau is 1.4 cm yr–1, 1980–2001, based on model studies and comparison with in situ borehole data. Here we report on the work in progress to quantify ALD rate increase in the northern Tibetan Plateau near the Tibetan national highway, using multi-band SAR/InSAR for improved the thermokarst surface classification, Envisat radar altimetry and ALOS-1 InSAR observed land subsidence, ALD modeling for the various thermokarst surface to relate to subsidence measurements, and the associated validations using available in situ borehole subsidence measurements.
