[M-GI25] Holocene paleoenvironment, paleoclimate, and paleohazards in the Pacific Islands

[MGI25-P01] The search of paleotsunami evidence at Nabukelevu, Kadavu Island, Fiji

*後藤 和久¹、池永 有弥¹、サウラ ミュール²、ジョジ マロダリ²、前野 深³、西澤 達治⁴、金子 隆之³、市原 美恵³ (1.東京大学大学院理学系研究科、2.フィジー鉱物資源局、3.東京大学地震研究所、4.山梨県富士山科学研究所)

In Fiji, information on historical and prehistoric tsunami events is rarely reported. This hampers adequate tsunami risk assessment. Geological evidence of tsunamis, such as sandy tsunami deposits and coral boulder deposits, is useful for understanding when and how large tsunamis occurred in the past. Based on these background, we started field research of paleotsunami in Fiji. We conducted preliminary research on Kadavu Island, where the Nabukelevu active volcano is located at the western end of the island. It is known that a local tsunami affected Nabukelevu village in 1959 (Nunn and Omura, 1999) causing damage and leading to the relocation of the village to higher ground. Around the beach near the village, we found fresh microatolls, which should have been in the coral reef, are deposited. Additionally, we observed sandy event deposits. The deposits contain marine fossils and thin landward, which are likely to have been deposited by tsunami or storm waves.

Acknowledgment: This research was supported by SATREPS (No. JPMJSA2309), JST/JICA and JSPS