The Tian Shan (Chinese for ‘Heavenly Mountain’), known as the ‘water tower of Central Asia’, has cultivated dense populations in this arid and semi-arid region via its well-developed glaciers. The mountain range stretches from the western boundary of Kyrgyzstan across most of Xinjiang, China, my hometown. The idea of studying glacial changes from the Little Ice Age in Chinese Tian Shan attracted the National Geographic Young Explorers Grants program which aims to improve our understanding of the Earth through helping cover field costs associated with research. With the support from this program, in summer 2012, my advisor Dr. Yingkui Li and I conducted a fieldtrip to collect rock samples from glacial land features (moraines) that characterize the Little Ice Age glacial advances.
My study is to examine the spatial pattern of Little Ice Age glacier advances across Chinese Tian Shan, which will help evaluate the controls of climate systems in Central Asia over millennial time scales. The Little Ice Age (LIA) is a cold period, approximately between AD 1400 and 1850, and studies have suggested that glaciers advanced during this period globally. However, quantitative examinations of LIA geomorphic features are limited, and the LIA glacial advances in Tian Shan have mainly been identified just based on field judgments.
One of the achievements that my study will produce is to use cosmogenic 10Be nuclide dating to constrain the absolute age of the putative LIA moraines, so that further we can determine the extent of the LIA glacial advances. The LIA extents in different places across the mountain range probably reflect the climate conditions in the past, such as shifting dominance of climate systems including westerlies and the Siberian high pressure system in this area.
From this exciting and productive expedition, we obtained 54 rock samples from the putative LIA moraines at four sites west-to-east across Chinese Tian Shan. I will continue to do the lab work and analyses to examine glacier changes in response to the past climate change in Tian Shan.