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

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

*Kazuhisa Goto¹, Yuya Ikenaga¹, Saula Mule², Joji Malodali², Fukashi Maeno³, Tatsuji Nishizawa⁴, KANEKO Takayuki³, Mie Ichihara³ (1.Department of Earth and Planetary Science, The University of Tokyo, 2.Mineral Resource Department, Fiji, 3.Earthquake Research Institute, The University of Tokyo, 4.Mount Fuji Research Institute, Yamanashi Prefectural Government)

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