A Review on Long-Term Evaluation of Occurrence Probability for Subduction-Zone Earthquakes in Eastern Japan

2012 ◽  
Vol 166-169 ◽  
pp. 2190-2196 ◽  
Author(s):  
Zheng Ru Tao ◽  
Xia Xin Tao ◽  
Wei Jiang

Evaluation approach of occurrence probability for subduction-zone earthquakes adopted in “National Seismic Hazard Maps for Japan” is reviewed, especially for the area of the 2011 off the Pacific coast of Tohoku Earthquake (2011 Tohoku Earthquake in short). One problem is pointed that the occurrence probability of such a large earthquake cannot be predicted just from seismicity in a region small like Miyagi-ken-Oki area or southern Sanriku-Oki. The whole subduction zone in eastern Japan is suggested to be taken into account with the interaction between the energy released in quakes. Finally, a simple test to predict the next large earthquake in the subduction-zone by means of Artificial Neural Network is presented, and the result for the years of 2008-2018 shows there may be an earthquake with magnitude up to 8.8 in the zone.

2013 ◽  
Vol 29 (1_suppl) ◽  
pp. 23-35 ◽  
Author(s):  
John G. Anderson

This paper selects several sites intended to represent relatively undistorted rock motions just inland from the faulting in the 2011 Tohoku-oki earthquake. Sites were selected for relatively high values of VS30 and for absence of strong site resonances. At these sites, ground motions at the surface were moderate, with peak accelerations of up to ∼330 cm/s2 and peak velocities up to ∼45 cm/s. Although moderate, these records imply that the strong motion generating area of the Tohoku earthquake was as much as ten times more energetic than the 1985 Michoacan earthquake, for which ground motions on rock were recorded above a strong motion generating area. These results suggest that a wide range of source parameters can occur in subduction zone earthquakes.


2021 ◽  
Author(s):  
Adam Beall ◽  
Fabio A. Capitanio ◽  
Ake Fagereng ◽  
Ylona van Dinther

<p>The largest and most devastating earthquakes on Earth occur along subduction zones. Here, long-term plate motions are accommodated in cycles of strain accumulation and release. Episodic strain release occurs by mechanisms ranging from rapid earthquakes to slow-slip and quasi-static creep along the plate interface. Slip styles can vary between and within subduction zones, though it is unclear what controls margin-scale variability. Current approaches to seismo-tectonics primarily relate the stress state and seismogenesis at subduction margins to interface material properties and plate kinematics, constrained by recorded seismic slip, GPS motions and integrated strain. At larger spatio-temporal scales, significant progress has been made towards the understanding of subduction dynamics and emerging self-consistent plate motions, tectonics and stress coupling at plate margins. The margin stress state is ultimately linked to the force balance arising from interactions between the slab, mantle flow and upper plate. These mantle and lithosphere dynamics are thus expected to govern the tectonic regimes under which seismicity occurs. It remains unclear how these longer- and shorter-term perspectives can be reconciled. We review the aspects of large-scale subduction dynamics that control tectonic loading at plate margins, discuss possible influences on the stress state of the plate interface, and summarise recent advances in integrating the earthquake cycle and large-scale dynamics. It is plausible that variations in large-scale subduction dynamics could systematically influence seismicity, though it remains unclear to what degree this interplay occurs directly through the plate interface stress state and/or indirectly, corresponding to variation of other subduction zone characteristics. While further constraints of the geodynamic controls on the nature of the plate interface and their incorporation into probabilistic earthquake models is required, their ongoing development holds promise for an improved understanding of the global variation of large earthquake occurrence and their associated risk.</p>


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