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| Titel |
Insights into the Tohoku earthquake rupture history from coastal uplift and tsunami deposits |
| VerfasserIn |
Mustapha Meghraoui, Silke Mechernich, Tsoyushi Haraguchi, Esra Cetin, Shinji Toda, Koji Okumura, Matthieu Ferry, Hiroyuki Tsutsumi |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077261
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| Zusammenfassung |
| The strain accumulating between M9-class earthquakes is a major component of the active deformation that contributes to resolve the pattern of seismic cycle at plate boundary zones. Recent geodetic and seismotectonic works constrain the ~ 500-km-long 2011 Tohoku megathrust rupture and related slip distribution. Here, we investigate marine terraces at 132 sites and palaeotsunami deposits at 7 estuaries in east Honshu and assess a prevailing late Quaternary coastal uplift and seismic coupling on a segmented Japan subduction zone. The tectonic process shows 0.2 and 0.4 mm/yr uplift rate of Pleistocene marine terraces in northern Tohoku, and 0.1 – 0.2 mm/yr along the Sanriku and southern Tohoku coastline. This variation depicts two active tectonic sub-regions where the area of low uplift rate correlates with the 2011 subsidence. Holocene benches and notches reveal ~ 1.1 mm/yr uplift rate in northern Tohoku which denotes clear upheaval acceleration during late Quaternary. The palaeotsunami record in the last 7 kyr on the Sanriku and Sendai coastline constrains the 400 – 800 years recurrence interval of palaeoearthquakes. Our modelling of crustal deformation indicates how the successive coastal subsidence during M9-class earthquakes may be concealed by the long term upheaval. |
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