Modern and possible paleotsunami deposits in Samenoura, Sanriku Coast, and their relation to tsunami source mechanisms

Simple item page
dc.contributor.authorSugawara, Den_AU
dc.contributor.authorNishimura, Yen_AU
dc.contributor.authorGoto, Ken_AU
dc.contributor.authorGoff, JRen_AU
dc.contributor.authorJaffe, BEen_AU
dc.contributor.authorRichmond, Ben_AU
dc.contributor.authorChagué-Goff, Cen_AU
dc.contributor.authorSzczuciński, Wen_AU
dc.contributor.authorYokoyama, Yen_AU
dc.contributor.authorMiyairi, Yen_AU
dc.contributor.authorSawada, Cen_AU
dc.date.accessioned2017-03-10T01:31:06Zen_AU
dc.date.available2017-03-10T01:31:06Zen_AU
dc.date.issued2014-05-02en_AU
dc.date.statistics2017-03-10en_AU
dc.description.abstractSamenoura is situated in the bay head of a small inlet on the Pacific coast of Oshika Peninsula, one of the nearest places to the epicenter of the 2011 Tohoku-oki Earthquake. According to the Joint Survey Group, wave heights were measured at more than 20 m near the coastline. This area was severely damaged as a result of both co-seismic subsidence and tsunami inundation. We carried out field surveys of the Tohoku-oki and paleotsunami deposits at Samenoura in March, May and October 2013. Sandy deposits laid down by the Tohoku-oki tsunami were up to 20 cm thick at locations with an elevation greater than 10 m, and were several cm thick within the forest higher up. The tsunami deposit also contained numerous shell fragments and foraminifera. Although some possible sources of the tsunami deposits can be attributed to narrow sandy beaches near the study area, the deposition of such a thick sandy deposit is more or less enigmatic, considering the steep Ria-type coastal topography.Using a gouge auger and geoslicer, we found at least two sand layers intercalated within muddy sediments. A volcanic ash layer, which corresponds to the AD 915 Towada-a tephra, was also identified from a horizon between these sand layers. The underlying sand layer was most probably laid down by the 869 Jogan earthquake tsunami, one of the large-scale events known to have affected the region. Previous studies of the Jogan tsunami have proposed several possible source models that involve an interplate thrust earthquake. Given that the local bathymetry and topography of Samenoura Bay may be sensitive to the waveform of a large-scale tsunami, paleotsunami deposits found from this area may be the key to determining the source mechanisms of events on the Sanriku Coast.In this presentation, the possible correlation of the sandy deposits with known paleotsunami events based on detailed radiocarbon dating is discussed. The hydrodynamic character and processes of tsunami sediment erosion and deposition in Samenoura Bay are analyzed using numerical modeling of both interplate and outer-rise earthquake scenarios. © Japan Geoscience Union Meeting, 2014.en_AU
dc.identifier.citationSugawara, D., Nishimura, Y., Goto, K., Goff, J., Jaffe, B., Richmond, B., Chagué-Goff, C., Szczuciński, W, Yokoya,a, Y., Miyairi, Y., & Sawada, C. (2014). Modern and possible Paleotsunami deposits in Samenoura, Sanriku Coast, and their relation to tsunami source mechanisms. Paper presented at the Japan Geoscience Union Meeting 28th April - 2nd May 2014, Pacifico Yokohama, Kanagawa, Japan.en_AU
dc.identifier.conferenceenddate2 May 2014en_AU
dc.identifier.conferencenameJapan Geoscience Union Meetingen_AU
dc.identifier.conferenceplaceKanagawa, Japanen_AU
dc.identifier.conferencestartdate28 April 2014en_AU
dc.identifier.govdoc8001en_AU
dc.identifier.other[M-IS23_2AM2]en_AU
dc.identifier.urihttps://confit.atlas.jp/guide/event/jpgu2014/subject/MIS23-10/detail?lang=enen_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/8458en_AU
dc.language.isoenen_AU
dc.publisherJapan Geoscience Union Meetingen_AU
dc.subjectEarthquakesen_AU
dc.subjectShoresen_AU
dc.subjectTsunamisen_AU
dc.subjectVolcanoesen_AU
dc.subjectAshesen_AU
dc.subjectErosionen_AU
dc.titleModern and possible paleotsunami deposits in Samenoura, Sanriku Coast, and their relation to tsunami source mechanismsen_AU
dc.typeConference Abstracten_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
pdf.pdf
Size:
37.89 KB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications