Localized tsunamigenic earthquakes inferred from preferential distribution of coastal boulders on the Ryukyu Islands, Japan

Abstract

Research Article| November 01, 2013 Localized tsunamigenic earthquakes inferred from preferential distribution of coastal boulders on the Ryukyu Islands, Japan Kazuhisa Goto; Kazuhisa Goto 1International Research Institute of Disaster Science, Tohoku University, Aoba 6-6-40-102, Aramaki, Aoba-ku, Sendai 980-8579, Japan Search for other works by this author on: GSW Google Scholar Kunimasa Miyagi; Kunimasa Miyagi 2Ishigaki-jima Island Local Meteorological Observatory, Japan Meteorological Agency, Tonoshiro 428, Ishigaki 907-0004, Japan Search for other works by this author on: GSW Google Scholar Fumihiko Imamura Fumihiko Imamura 1International Research Institute of Disaster Science, Tohoku University, Aoba 6-6-40-102, Aramaki, Aoba-ku, Sendai 980-8579, Japan Search for other works by this author on: GSW Google Scholar Geology (2013) 41 (11): 1139–1142. https://doi.org/10.1130/G34823.1 Article history received: 08 Jun 2013 rev-recd: 07 Jul 2013 accepted: 11 Jul 2013 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Kazuhisa Goto, Kunimasa Miyagi, Fumihiko Imamura; Localized tsunamigenic earthquakes inferred from preferential distribution of coastal boulders on the Ryukyu Islands, Japan. Geology 2013;; 41 (11): 1139–1142. doi: https://doi.org/10.1130/G34823.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The occurrence of large earthquakes and tsunamis along the Ryukyu Trench is a subject of continuing interest, the key to which is the long-term geological record. Here we describe the clast size and spatial distributions of ∼2900 boulders on the reefs of the Ryukyu Islands, Japan, as markers of paleotsunamis and causative tsunamigenic earthquakes. Boulders of tsunami origin were observed only at a specific island group at the southern end, suggesting the local occurrence of tsunamigenic earthquakes there. In contrast, in the central to northern Ryukyu Islands, no evidence exists of tsunamis larger than those at the southern end of the Ryukyu Islands during the past 2000–3000 yr. These islands have numerous boulders deposited by storm waves during the past 2300 yr or earlier. Their spatial distribution has not been disturbed by large tsunamis. This suggests that large tsunamis did not strike this area during that period; nevertheless, these regions are seismically active. Our study shows that coastal boulder deposits present great potential to not only ascertain the histories and effects of paleotsunamis but also to constrain fault models of the causative earthquakes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.