Jingdong Zhao

Thinning and Shrinkage of Laohugou No. 12 Glacier in the Western Qilian Mountains, China, from 1957 to 2007

Landsat images, real-time kinematic GPS measurements, and topographic maps were used to determine changes in ice elevation, volume, and areal extent of the Laohugou No. 12 glacier (Qilian Mountains, China) between 1957 and 2007. The glacier experienced significant thinning and areal shrinkage in the ablation zone, but slight thickening in part of the accumulation zone. Elevation decreased by 18.6±5.4 m between 1957 and 2007 in the regions covered by the GPS measurements. The total volume loss for the entire glacier was estimated to be 0.218 km3 using a third-order polynomial fit method. The area diminished by 0.28 km2 between 1957 and 1994, 0.26 km2 between 1994 and 2000, and 0.28 km2 between 2000 and 2007, suggesting that the rate of loss in glacial coverage has increased since the mid-1990s. Significant increases in annual mean air temperature may have contributed to shrinkage and thinning of the glacier.

Chapter 70 – Quaternary Glaciations: Extent and Chronology in China

Quaternary Glaciations in Tibetan Plateau were restricted to mountain glaciers. Four Pleistocene glaciations were identified to occurred during MIS 18~16, MIS 12, MIS 6 and MIS 4~2. The total area for the most extensive glaciation was smaller than 5×105 km2. The Kunlun-Huanghe and Gonghe tectonic uplifts of the Plateau have played the very important role in triggering glaciations in the high Asia region.