Geodynamic and Climate Interaction in the Kurile-Kamchatka and Aleutean Marginal Sea-Island Arc System

The Kurile-Kamchatka and Aleutean Marginal Sea-Island Arc System is a complex climate driving region. To better understand the processes that control the subduction and the geodynamic and climatic development in this region a joint group of German and Russian scientists work together under the frame of the KALMAR project. In five closely coupled subprojects multidisciplinary research is carried out that involves a wide range of geophysical, tectonic, volcanological and petrological approaches as well as paleo-oceanographic and climate research. Several land expeditions on Kamchatka and three geomarine cruises in the NW-Pacific and the western Bering Sea are the bases for the research. The cruises with the German research vessel SONNE in 2009 concentrated on the geophysical investigation of the subducting plate offshore Kamchatka (SO201 Leg 1a), and on volcanological, petrological, tectonic and paleoceanographic questions (SO201 Leg 1b, SO201 Leg 2). The focus of the cruises was the study on the composition of the mantle and the oceanic crust, the seamounts and their ages as well as paleo-oceanographic investigations on the sediments along the eastern continental slope of Kamchatka, in the Komandorsky Basin, and on the Shirshov Ridge to explore paleoclimate archives to get an insight in the subpolar water mass transfer and the oceanographic and climatic development in the subarctic NW-Pacific. The geochemical refinement of a tephrostratigraphic framework of Pleistocene and Holocene tephra in Kamchatka provided a detailed chronology of Holocene Kamchatkan eruptions. It served as a basis for understanding temporal patterns in the eruption sequence and geochemical variations of magmas. It provides independent time markers for an exact correlation of the various climate archives from land and marine sites from the NW-Pacific and the Bering Sea. It needs to be proved, if Kamchatkan ashes can be traced into the Eastern Bering Sea and offshore Alaska.