News from the ICDP Project NamCore, Tibet – (hopefully) shortly after the drilling

To define parameters for future climate change scenarios (IPCC) and their consequences for ecosystems, it is of paramount importance to improve our knowledge of timing, duration, and intensity of past climatic variability and subsequent environmental impact, especially on long geologic time scales and in key regions such as the Tibetan Plateau. Considering that the Tibetan Plateau serves as the source of several major rivers the future hydrological development will clearly have a significant societal impact. Nam Co is one of the largest and deepest lakes on the Tibetan Plateau. Due to this location at the intersection of Monsoon (increased precipitation) and Westerlies (increased evaporation) paleoclimate proxies derived from sediments of Nam Co clearly reflect the spatial and temporal interplay and thus the dominance of one of the two circulation systems.

Seismic data show that the Nam Co basin contains >800 m of well layered undisturbed sediments. Sediment accumulation rates measured on a 10.4 m reference core, seismostratigraphic investigations, and molecular clock analyses suggest an age of the seismically imaged sequence of >1 Mio years. Instead of drilling the entire >800 m sediment sequence in the center of the lake we will use the fact that layers are dipping towards the center of Nam Co producing a higher accumulation rate there. By splicing together multiple cores from three different sites it will be possible to cover the same depositional history found at >800 m in the center, i.e., 1 Ma.