13:45 〜 15:15
[MIS02-P02] Evolution of the Kuroshio Current over the last 10 million years
キーワード：North Pacific、Kuroshio、Monsoon、Radiolaria
Recent studies suggested that the 2100 climate may be close to those during the middle Miocene Climatic Optimum (MMCO) (~15 Ma). Indeed, since the MMCO, Earth’s climate underwent a series of cooling events establishing modern meridional gradient, climate, and ecological systems. Among, the Late Miocene Global Cooling (LMGC, 7.5-5.5 Ma), the Northern Hemisphere Glaciation (NHG, 3.0-2.7 Ma) and the Mid Pleistocene Transition (MPT, 1.2-0.8 Ma) are the three main cooling events defining the outlines of our modern climate.
The Kuroshio Current (KC) is a warm oceanic current flowing north on the western side of the North Pacific Ocean basin. The KC plays an important role in controlling the oceanography and climate of the Northwest Pacific due to its relationship to the phenomenon of El Nino and the Asian monsoon system. Therefore, the monitoring of the variability of the KC during late Neogene cooling events as the LMGC, NHG and the MPT would allow us to understand how each cooling event impacted the regional climate.
In this context I analyzed 79 samples from ODP Site 1208 (36.1°N, 158.2°E), which is located within the Kuroshio Current Extension (KCE), the poleward limb of the North Pacific subtropical gyre. I analyzed the interval from 0 and 260 mbsf, which corresponds to the last 10 millions years for be able to discuss the impact of the LMGC, NHG and the MPT on the KC.
I analyzed radiolarian assemblages for discuss paleoceanographic changes at Site 1208 because it has been demonstrated that this fossil group to be a suitable paleoceanographic proxy in the Northwest Pacific Neogene sequences in particular for sediment cored below the calcite compensation depths. In this poster I show preliminary radiolarian results in order to have an global insight on possible changes in the KC during the LMGC, NHG and the MPT .
The Kuroshio Current (KC) is a warm oceanic current flowing north on the western side of the North Pacific Ocean basin. The KC plays an important role in controlling the oceanography and climate of the Northwest Pacific due to its relationship to the phenomenon of El Nino and the Asian monsoon system. Therefore, the monitoring of the variability of the KC during late Neogene cooling events as the LMGC, NHG and the MPT would allow us to understand how each cooling event impacted the regional climate.
In this context I analyzed 79 samples from ODP Site 1208 (36.1°N, 158.2°E), which is located within the Kuroshio Current Extension (KCE), the poleward limb of the North Pacific subtropical gyre. I analyzed the interval from 0 and 260 mbsf, which corresponds to the last 10 millions years for be able to discuss the impact of the LMGC, NHG and the MPT on the KC.
I analyzed radiolarian assemblages for discuss paleoceanographic changes at Site 1208 because it has been demonstrated that this fossil group to be a suitable paleoceanographic proxy in the Northwest Pacific Neogene sequences in particular for sediment cored below the calcite compensation depths. In this poster I show preliminary radiolarian results in order to have an global insight on possible changes in the KC during the LMGC, NHG and the MPT .