Expedition 346 summary

Abstract

Integrated Ocean Drilling Program (IODP) Expedition 346 drilled seven sites covering a wide latitudinal range in the body of water bordered by the Eurasian continent, the Korean Peninsula, and the Japanese Islands, as well as two closely spaced sites in the East China Sea. This expedition recovered 6135.3 m of core with an average recovery of 101%—a record amount of core recovered during any single IODP expedition. Expedition 346 was the first scientific drilling expedition ever to focus exclusively on the climate system in this region, which is at once so critical yet potentially vulnerable to the challenges society faces in the coming years of global climate change. With the East Asian Monsoon directly affecting the water supply of one-third of the global population, the expedition scientific results and postexpedition research that will follow have direct bearing on society’s understanding of this complex atmosphere-ocean climate system. The high quality of materials recovered and the complete documentation of their geological, geochemical, and geophysical context will lead to an unparalleled series of future studies by the expedition Science Party as well as many other scientists over the coming decades. Cores obtained during this expedition will be used to test the hypothesis that Pliocene–Pleistocene uplift of the Himalaya and Tibetan Plateau, and the consequent emergence of the two discrete modes of Westerly Jet circulation, caused the amplification of millennial-scale variability of the East Asian summer monsoon and East Asian winter monsoon and provided teleconnection mechanism(s) for Dansgaard–Oeschger cycles.