Friday, 6 July 2018

Past climates of the western Tibetan Plateau…by Yuzhi Zhang

Hi. I am Yuzhi, a PhD student from Lanzhou University (China) currently on secondment to the School of Geography (University of Nottingham) and the Centre for Environmental Geochemistry at BGS. I am working on reconstructing the climate and environmental change in the western Tibetan Plateau over the Holocene period from lake sediments. In the UK my placement is specifically to gain experience with geochemical proxies including stable isotopes at the BGS.

Yuzhi undertaking fieldwork in the alpine region of the Tibetian Plateau.
There are more than 1000 lakes located in the Tibetan Plateau, and its fragile ecosystem is very sensitive to climate variations.  Therefore, it is important to look at past changes in the environment to understand how climate change will impact the region in the future.

Although a lot of work has been done in the eastern and southern Tibetan Plateau, little has been done in the west. Different regions across the Tibetan Plateau are influenced by different atmospheric circulation systems (ie Indian Summer Monsoon and Westerlies) so it is essential to know the palaeoclimate change in the different regions.  This will give us a better understanding of the variability of the Indian Summer Monsoon (ISM). Water resources on the Tibetan Plateau are of great importance in understanding the history of human civilization in this region.

Lake A’ong Co in Western Tibetian Plateau.
I have been working on an alpine lake, A’ong Co, which is a glacier-fed lake. In 2015, I took a 4.5 m long core from the central part of the lake. Palaeolimnological proxies, including stable isotopes and ostracode species, are being used to reconstruct the climate change (mainly wet-dry variations) through the Holocene. Specifically I want to investigate the past influence of the Indian Summer Monsoon. As A’ong Co is a glacier-fed lake, I am also investigating the source of the lake water and how sensitive it is to variations in glacier melt, as well as carbon cycling in the lake and its connection with climate change.

Yuzhi Zhang is a PhD student currently on secondment in the School of Geography, University of Nottingham working within the Centre for Environmental Geochemistry in BGS.

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