JpGU-AGU Joint Meeting 2017

Presentation information

[JJ] Poster

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS23] [JJ] Paleoclimatology and paleoceanography

Tue. May 23, 2017 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall HALL7)

convener:Tomohisa Irino(Faculty of Environmental Earth Science, Hokkaido University), Akira Oka(Atmosphere and Ocean Research Institute, The University of Tokyo), Ikuko Kitaba(Research Centre for Palaleoclimatology, Ritsumeikan University), Masaki Sano(Research Institute for Humanity and Nature)

[MIS23-P15] Preliminary reconstruction of Lake-level changes based on fossil diatom assemblages in Lake Biwa

*Takashi Suzuki1, Yoshio Inouchi2, Keisuke Otsuka1 (1.Graduate School of Human Science, Waseda University, 2.Faculty of Human Sciences, Waseda University)

Keywords:Lake Biwa, off estuary of Echi River, drilling core, planktonic diatom, transfer function, lake-level change

This is a preliminary report of a research for reconstruction of lake-level change history of Lake Biwa based on the transfer function of diatom assemblage into water depth of surface sediment. We investigated diatom assemblages in drilling core sample from the lake bottom and surface sediment samples from the lake bottom from 5 m to 30 m in depth off estuary of Echi River, Lake Biwa.
Rate of planktonic species and water depth can be changed into the transfer function. The transfer function applied to drilled sediment from Lake Biwa into lake-level change history.The result shows that lake-level changes in Lake Biwa reflects climate changes. Before 1.5 ka, water depth rose under relatively cold conditions. During the last 1.5 ka, water depth rose under relatively warm conditions. The difference of response to climate condition suggests that snowfall in winter depending on East Asian winter monsoon and rainfall in summer depending on East Asian summer monsoon influence water balance of Lake Biwa.