How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench

Abstract Deep-sea turbidite has been used to determine the history of occurrence of large earthquakes. Surface-sediment remobilization is a mechanism of the generation of earthquake-induced turbidity currents. However, the detailed mechanism of surface-sediment remobilization caused by earthquake gr...

Full description

Bibliographic Details
Main Authors: Ken Ikehara, Kazuko Usami, Toshiya Kanamatsu
Format: Article
Language:English
Published: SpringerOpen 2023-02-01
Series:Progress in Earth and Planetary Science
Subjects:
Online Access:https://doi.org/10.1186/s40645-023-00540-8
_version_ 1797853554236456960
author Ken Ikehara
Kazuko Usami
Toshiya Kanamatsu
author_facet Ken Ikehara
Kazuko Usami
Toshiya Kanamatsu
author_sort Ken Ikehara
collection DOAJ
description Abstract Deep-sea turbidite has been used to determine the history of occurrence of large earthquakes. Surface-sediment remobilization is a mechanism of the generation of earthquake-induced turbidity currents. However, the detailed mechanism of surface-sediment remobilization caused by earthquake ground shaking is unclear. To understand how high peak ground acceleration (PGA) caused by a large earthquake can remobilize surface sediments, we determined the age of a surface-sediment core recovered from the mid-slope terrace (MST) of the inner slope of the Japan Trench in northern Sanriku to determine turbidites generated by large historical earthquakes and calculate the PGAs of these earthquakes using an empirical attenuation relation commonly used in Japan. Small offsets in radiocarbon ages and excess 210Pb activities between turbidite and hemipelagic muds suggest that the turbidites in the core resulted from surface-sediment remobilization. 137Cs and excess 210Pb chronologies indicate that the three uppermost turbidites in the core are correlated with three large historical earthquakes, namely the 1968 common era (CE) Tokachi-oki, the 1933 CE Showa–Sanriku, and the 1896 CE Meiji–Sanriku earthquakes. Calculation of PGAs for large historical earthquakes along the northern Japan Trench indicates that a PGA of > 0.6 g is necessary for turbidite deposition in the MST basin. This threshold is larger than that reported for central Sanriku and may vary spatially. Moreover, turbidites in the MST deposits are more frequent in the northern Japan Trench than in the central Japan Trench, suggesting that the occurrence of three types of large M8-class earthquakes in the northern Japan Trench might have contributed to the frequent occurrence of large PGAs.
first_indexed 2024-04-09T19:51:25Z
format Article
id doaj.art-e4f1912ea39e462597f9e3db97ee9f32
institution Directory Open Access Journal
issn 2197-4284
language English
last_indexed 2024-04-09T19:51:25Z
publishDate 2023-02-01
publisher SpringerOpen
record_format Article
series Progress in Earth and Planetary Science
spelling doaj.art-e4f1912ea39e462597f9e3db97ee9f322023-04-03T05:44:23ZengSpringerOpenProgress in Earth and Planetary Science2197-42842023-02-0110111210.1186/s40645-023-00540-8How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan TrenchKen Ikehara0Kazuko Usami1Toshiya Kanamatsu2Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST)Japan NUS Co. Ltd.Research Institute of Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)Abstract Deep-sea turbidite has been used to determine the history of occurrence of large earthquakes. Surface-sediment remobilization is a mechanism of the generation of earthquake-induced turbidity currents. However, the detailed mechanism of surface-sediment remobilization caused by earthquake ground shaking is unclear. To understand how high peak ground acceleration (PGA) caused by a large earthquake can remobilize surface sediments, we determined the age of a surface-sediment core recovered from the mid-slope terrace (MST) of the inner slope of the Japan Trench in northern Sanriku to determine turbidites generated by large historical earthquakes and calculate the PGAs of these earthquakes using an empirical attenuation relation commonly used in Japan. Small offsets in radiocarbon ages and excess 210Pb activities between turbidite and hemipelagic muds suggest that the turbidites in the core resulted from surface-sediment remobilization. 137Cs and excess 210Pb chronologies indicate that the three uppermost turbidites in the core are correlated with three large historical earthquakes, namely the 1968 common era (CE) Tokachi-oki, the 1933 CE Showa–Sanriku, and the 1896 CE Meiji–Sanriku earthquakes. Calculation of PGAs for large historical earthquakes along the northern Japan Trench indicates that a PGA of > 0.6 g is necessary for turbidite deposition in the MST basin. This threshold is larger than that reported for central Sanriku and may vary spatially. Moreover, turbidites in the MST deposits are more frequent in the northern Japan Trench than in the central Japan Trench, suggesting that the occurrence of three types of large M8-class earthquakes in the northern Japan Trench might have contributed to the frequent occurrence of large PGAs.https://doi.org/10.1186/s40645-023-00540-8PaleoseismologyHistorical earthquakePeak ground accelerationTurbiditeJapan Trench
spellingShingle Ken Ikehara
Kazuko Usami
Toshiya Kanamatsu
How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench
Progress in Earth and Planetary Science
Paleoseismology
Historical earthquake
Peak ground acceleration
Turbidite
Japan Trench
title How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench
title_full How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench
title_fullStr How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench
title_full_unstemmed How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench
title_short How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench
title_sort how large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern japan trench
topic Paleoseismology
Historical earthquake
Peak ground acceleration
Turbidite
Japan Trench
url https://doi.org/10.1186/s40645-023-00540-8
work_keys_str_mv AT kenikehara howlargepeakgroundaccelerationbylargeearthquakescouldgenerateturbiditycurrentsalongtheslopeofnorthernjapantrench
AT kazukousami howlargepeakgroundaccelerationbylargeearthquakescouldgenerateturbiditycurrentsalongtheslopeofnorthernjapantrench
AT toshiyakanamatsu howlargepeakgroundaccelerationbylargeearthquakescouldgenerateturbiditycurrentsalongtheslopeofnorthernjapantrench