Uplift of high topography in Asia has often been linked to the intensification of the Asian monsoon during the Cenozoic, although the timing of initial monsoon strengthening continues to be debated. Conversely, stronger erosion caused by heavier rains have been linked to the exhumation of the Greater Himalaya starting in the Early Miocene. While models continue to be developed these are not always well constrained by observations. Sedimentary records in South Asia are limited to ~20 Ma in the Himalayan foreland basin, as well as to the submarine fans systems of the Indian Ocean and South China Sea, Recent drilling by IODP now provides a much improved Neogene record of changing erosion and weathering onshore, as well as evolving biogenic productivity and oceanic upwelling offshore. It is clear that marine and terrestrial proxies are rarely in agreement even when modern observations suggest that they should be. In general we see a history of peak monsoon rainfall in the Middle Miocene followed by drying in most areas, especially after 8 Ma, but with more variability and periods of strong summer monsoon after the onset of Northern Hemispheric Glaciation. The growth of topography appears critical in steering the moisture but the strength is largely a function of global climate. The Asian and Australian monsoon are largely disconnected, with the latter being more affected by the Indonesian Throughflow.
12.09.2022, 13:15 Uhr
MARUM Seminar room 2060