Open AccessSeafloor morphology and sediment magnetic fabric in a putative 1771 Meiwa tsunami source region in the southern Ryukyu Islands, SW Japan
Author(s) -
Toshiya Kanamatsu,
Ken Ikehara,
Ayanori Misawa
Publication year - 2020
Publication title -
special publication - geological society of london/geological society, london, special publications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.673
H-Index - 132
eISSN - 2041-4927
pISSN - 0305-8719
DOI - 10.1144/sp501-2019-94
Subject(s) - forearc , seafloor spreading , submarine landslide , geology , landslide , bathymetry , seismology , tectonics , submarine , submarine pipeline , sediment , mass movement , paleontology , geomorphology , oceanography , subduction
The Meiwa tsunami of AD 1771 is regarded as an extremely strong tsunami event causing devastating damage in Japan in historical times. Earlier studies explored the possibility that a submarine landslide enhanced the Meiwa tsunami waves. We collected detailed seafloor bathymetry data, sub-bottom structure data and surface sediments in a putative Meiwa tsunami source region to ascertain any signature related to a submarine landslide in the forearc region, which is located south of Ishigaki-jima. The forearc-region seafloor is characterized by its surface submarine landslide morphology. However, the investigated magnetic fabric of surface sediment revealed that there was no landslide mass deposit during historical times. The described landslide morphology in the basin is unrelated to the generation or enhancement of the AD 1771 Meiwa tsunami, although the disturbed relief in the topography of the study area indicates that the forearc region is susceptible to slope failure because of its tectonic setting.