Past hydroclimate changes on the southern Thar Desert margin

Project description

Paleoclimate evidence from global deserts suggest that these regions have undergone periods of contraction and expansion after the last glacial period. The Thar Desert in Northwestern India is a classic example which saw the development of several lakes when summer monsoon rain intensified after the last glacial period. At present most of the lakes are dried up and are covered by sand dunes suggesting that the hydroclimate of the region has changed significantly during the last 10,000 years. While there are several studies on past climate reconstructions from the northern Thar Desert margin, the evolution of the southern Thar Desert margin remains relatively unexplored. As this region is projected as one of the most vulnerable regions to future climate change, a better understanding of how it has evolved in the past in response to various climate drivers is required. This region was also one of the densely populated regions of the world about 5000 years ago by the Bronze age Indus civilization, stressing the importance of understanding the past climate change that led to their decline.

This project aims at reconstruction of high-resolution past monsoon changes recorded in paleolake sediments in the southern Thar Desert margin. Lake sediment and shell carbonate chemistry will be used for past rainfall reconstructions and mapping the transformation of wet to dry periods. The oxygen isotopic composition of biogenic shells found in lake sediments will be used to infer rainfall changes, while the carbon isotope composition of organic matter indicates past vegetational changes. The successful candidate will identify suitable lake archives on the southern desert margin, followed by sampling and processing of sediments for chemical composition using X-Ray Fluorescence and ICP-OES techniques at IITD. Preliminary results will help identify key intervals, and stable isotopic and elemental analysis will be carried out at UQ.

Outcomes

The project will provide new climate and hydrological records of the Thar desert margin over the last 10,000 years. These records will be used to map the response of local climate and precipitation to global climate change. This is highly important as the region is predicted to face increasing drought and drying with anthropogenic global warming, and an understanding of past climates aids our ability to predict future climate. An additional aspect of this project as it will help to understand the rise and fall of the Indus civilization, where a drying of the landscape is thought to have triggered civilizational collapse.

Essential capabilities

Chemistry, climate, or physical science background

Desireable capabilities

Geology experience,

Expected qualifications (Course/Degrees etc.)

Bachelors/Masters in a physical science discipline