scholarly journals Excitation of back-arc tsunamis from megathrust ruptures: The underdog hazard in the Sea of Japan

2021 ◽  
Author(s):  
Amir Salaree ◽  
Yihe Huang
Keyword(s):  
Sea Of Japan ◽  
Tohoku Earthquake ◽  
Japan Trench ◽  
Dislocation Model ◽  
The Sea Of Japan ◽  
Japan Basin ◽  
The 2011 Tohoku Earthquake ◽  
Megathrust Earthquakes ◽  
Back Arc ◽  
Arc Propagation

The 2011 Tohoku earthquake created a moderate tsunami in the back-arc Sea of Japan basin. This tsunami went largely unnoticed due to its small size and the significant coverage of the large fore-arc waves. We present a physical dislocation model for the excitation of back-arc tsunamis and identify fault dip as the main geometrical contributor to the propagation of back-arc tsunamis. Using numerical simulations and data from the 2011 event, we show that a combination of near- to intermediate-field horizontal and vertical dislocations as well as transient surface waves is necessary to reconstruct the back-arc propagation. We then simulate potential future earthquakes in the Japan trench and Nankai trough to investigate the back-arc tsunami hazard in the Sea of Japan. Our results show that the coseismic excitation of back-arc tsunamis can result in considerable waves exceeding 1 m from megathrust earthquakes.

Tsunami Forerunner of the 2011 Tohoku Earthquake Observed in the Sea of Japan

2014 ◽  
Vol 172 (3-4) ◽  
pp. 683-697 ◽  
Author(s):  
Satoko Murotani ◽  
Maki Iwai ◽  
Kenji Satake ◽  
Georgy Shevchenko ◽  
Artem Loskutov
Keyword(s):  
Sea Of Japan ◽  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
The Sea Of Japan ◽  
The 2011 Tohoku Earthquake

scholarly journals Alkali basalt from the Seifu Seamount in the Sea of Japan: post-spreading magmatism in a back-arc setting

Solid Earth ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23-36
Author(s):  
Tomoaki Morishita ◽  
Naoto Hirano ◽  
Hirochika Sumino ◽  
Hiroshi Sato ◽  
Tomoyuki Shibata ◽  
...  
Keyword(s):  
Partial Melting ◽  
Sea Of Japan ◽  
Alkali Basalt ◽  
Spinel Peridotite ◽  
The Sea Of Japan ◽  
Low Degree ◽  
Tsushima Basin ◽  
Arc Setting ◽  
Element Enrichment ◽  
Back Arc

Abstract. We present geochemical and 40Ar∕39Ar age data for a peridotite xenolith-bearing basalt dredged from the Seifu Seamount (SSM basalt) in the northeast Tsushima Basin, southwest Sea of Japan. An 40Ar∕39Ar plateau age of 8.33±0.15 Ma (2σ) was obtained for the SSM basalt, indicating that it erupted shortly after the termination of back-arc spreading in the Sea of Japan. The SSM basalt is a high-K to shoshonitic alkali basalt that is characterized by light rare earth element enrichment. The trace element features of the basalt are similar to those of ocean island basalt, although the Yb content is much higher, indicating formation by the low-degree partial melting of spinel peridotite. The Nd, Sr, and Pb isotopic compositions of the SSM basalt differ from those of back-arc basin basalts in the Sea of Japan. The Sr–Nd isotopic composition of the SSM basalt suggests its source was depleted mid-ocean ridge mantle containing an enriched mantle (EM1) component. The SSM basalt was formed in a post-back-arc extension setting by the low-degree partial melting of an upwelling asthenosphere that had previously been associated with the main phase of back-arc magmatism.

scholarly journals Joint estimate of the co-seismic 2011 Tohoku earthquake fault slip and post-seismic viscoelastic relaxation by GRACE data inversion

2019 ◽  
Author(s):  
G Cambiotti
Keyword(s):  
Temporal Resolution ◽  
Subduction Zones ◽  
Gravity Data ◽  
Tohoku Earthquake ◽  
Fault Slip ◽  
2011 Tohoku Earthquake ◽  
The 2011 Tohoku Earthquake ◽  
Physical Constraints ◽  
Megathrust Earthquakes ◽  
Grace Data

SUMMARY Satellite-derived gravity data offer a novel perspective for understanding the physics of megathrust earthquakes at subduction zones. Nonetheless, their temporal resolution and observational errors make it difficult to discern the different phases of the seismic cycle, as the elastostatic deformation (co-seismic) and the stress relaxation by viscous flow (post-seismic). To overcome these difficulties and to take advantage of the physical constraints on the temporal evolution and on the spatial pattern of the earthquake-induced gravity disturbances, we have jointly estimated the fault slip of the 2011 Tohoku earthquake and the rheological stratification by means of a Bayesian inversion of GRACE data time series and within the framework of spherically symmetric self-gravitating compressible viscoelastic Earth models. This approach, in addition to improve the exploitation of satellite-derived gravity data, allows us (i) to constrain the fault slip taking advantage of information from both the co- and post-seismic signatures and (ii) to investigate the trade-off between the fault slip and the shallow rheological stratification. In this respect, it can be used to improve the modelling of crustal displacements from GPS data, even if their higher accuracy and temporal resolution allow to discriminate well the co-seismic signature from the others.

Evolution of the Sea of Japan back-arc and some unsolved issues

2017 ◽  
Vol 710-711 ◽  
pp. 6-20 ◽  
Author(s):  
Anne Van Horne ◽  
Hiroshi Sato ◽  
Tatsuya Ishiyama
Keyword(s):  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Back Arc
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