Senckenberg Research

Arabian Sea

The Arabian Sea is influenced by a seasonal monsoon cycle with strong SW winds in summer and moderate to strong NE winds in winter. The seasonally changing monsoons affect sea surface temperatures and ocean circulation and thus control productivity and processes in the water column.

In this project the interplay of the Indian monsoon and the Westerlies shall be reconstructed to identify tipping points in the climate system. A partially laminated and 7-meter-long sediment core from the Pakistan continental slope that covers the entire Holocene allows with the measurement of alkenone concentrations the reconstruction of sea surface temperatures as an indicator of the monsoon strength and variability. In addition, studies of productivity indicators such as accumulation rates of organic carbon or nitrogen and indicators for the intensity of the oxygen minimum zone provide additional information on climate changes and interactions with biogeochemical cycles. Furthermore, the lithogenic sediment fraction can be used for a reconstruction of winter precipitation and thus for the strength of the influence of the Westerlies.

Planktic foraminifers shall be used for radiocarbon dating in order to establish a precise age model for the core. Furthermore, the frequency of extreme climate events can be reconstructed by counting event layers in the core. If possible, these events shall be correlated with those of already investigated sediment cores in the region in order to better understand the spatial extent and thus the regional significance of catastrophic flood events.