Two million year history of the Indian Monsoon

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Over 3 billion people live in the area influenced by the Asian monsoon, the rains of which provide vital water resources while posing a risk to human life through flooding. Despite the importance to so many the monsoon is difficult to predict and model, making its future development in a changing global climate uncertain. To help improve models and predictions, histories of monsoon variability beyond the instrumental record are required. Many records of the East Asian monsoon have been generated from China and the South China Sea while past variability of the Indian Monsoon is mostly known from records of monsoon wind strength over the Arabian Sea. Here we propose to use the unique long sediment core obtained by the IODP vessel JOIDES Resolution in the Andaman Sea to examine the past variability of Indian Monsoon precipitation on the Indian sub-continent and directly over the ocean. Our multi-proxy approach will reveal changes in continental weathering, runoff and direct precipitation on orbital timescales for the last 2 million years filling a fundamental gap in our understanding of the Indian Monsoon in the past. More detailed studies will examine variations on millennial timescales for the last glacial and deglaciation, and the novel application of single foraminifera shell geochemistry will allow variability on inter-annual and seasonal timescales to be investigated for selected intervals.