Workshop on Climate-Tectonic Drilling in Southeast Asia

June 5-7, 2006 – Kochi, Japan
Convener: Peter Clift, Wonn Soh

Summary

 

Interactions between the tectonic evolution of the solid Earth and the planet’s climate system have been recognized, yet are presently only understood in outline. The Asian monsoon – Himalaya-Tibetan Plateau system appears to be one of the most dramatic examples of such interactions and is ideally suited for deconvolving and unraveling the coupling that can occur between high topography and the climate system. Climate models suggest a strong linkage between Tibetan altitude and the strength of the monsoon. However, these models are largely untested. A meeting was held 5–7th June 2006 in Kochi, Japan, to discuss marine and terrestrial geoscience research on the subject of climate-tectonic studies focused in SE Asia. The meeting summarized recent research advances in the field and recommended the coordination of research activities across the region, particularly in the context of the Integrated Ocean Drilling Program (IODP). SE Asia is particularly well suited to this type of work because the Asian monsoon is strong and the rivers of the region incise the edge of the Tibetan Plateau. Recent advances in the science of climate-tectonic coupling include new evidence for the monsoon experiencing a series of steps in intensification, possibly dating back to the Early Miocene ~25 Ma. Furthermore, while central Tibet appears to have been relatively high possibly back to >30 Ma, the NE and SE edges appear to have been elevated only since 10 Ma. Phases of plateau uplift or climate change must generate erosional pulses that are delivered to the deltas of the marginal seas, where they can be sampled and quantified. The importance of drilling in the Song Hong-Yinggehai Basin was recognized as an important step to testing models for climate change in East Asia. However, the erosional pulses observed can only be interpreted if the uplift and exhumation histories of the sources in SE Tibet can be reconstructed in detail and if variations in monsoonal climate can also be dated. Because of variations in the nature of the monsoon across Asia, and because the source rivers have interacted with each other in the past, drilling in the Red River fan-delta alone will be insufficient to address the science goals of the community. The meeting called for coordinated drilling in the Sea of Japan/East Sea, in the East China Sea and in the Mekong delta, which in turn must be linked to related programs on the Indus and Bengal Fans in the Indian Ocean. Ocean drilling will need to be supplemented in key regions by continental coring operations, with the Hanoi Basin, the Jianghan and Subei Basins of the Yangtze River, and smaller sedimentary basins in SE Tibet particularly highlighted.

 

Organizing Committee

 

Peter D. Clift, University of Aberdeen
Wonn Soh, Kochi Institute for Core Sample Research, JAMSTEC