Holocene sea-level changes in Japan coastal areas recovered from the brackish lake sediment cores based on physical properties and geochemical analysis

Nara, Fumiko   ; Kida, Fukuka; Ochiai, Shinya*; Watanabe, Takahiro   ; Matsunaka, Tetsuya*; Hashino, Kotaro*; Yamasaki, Shinichi*; Tsuchiya, Noriyoshi*

In our current research, we are focusing on using the brackish lake sediments from Lake Kibagata (Komatsu city, Ishikawa prefecture) on the Japan Sea coast to gain information about the past sea-level changes. Contrary to the Pacific side, the study of the past sea level changes on the Japan Sea side is still limited. To clarify the past sea level response to climate-induced water mass changes, either eustatic or due to GIA, understanding the past sea-level changes in relatively enclosed environments, such as the Japan Sea, is essential. Lake Kibagata is located about 5 km inland from the coastline of the Japan Sea and has not undergone large-scale artificial modifications such as land reclamation. The physical properties (CT image, porosity and magnetic susceptibility, which measured by the multi senser core logger at Kochi Core Center under Kochi Core Center Open Facility System) and the geochemical (Br, I, and trace elements measured by XRF) analysis were conducted on the core KB2023. Based on these data, we will present a report on the past sea level changes at the late Holocene that took place along the Japan Sea coast.