Progress in Earth and Planetary Science

A number of new discoveries have been made in the aftermath of the 2011 Tohoku earthquake, thanks to unprecedented near-field observations as well as to the earth scientific knowledge about the northeastern Japan arc that has accumulated prior to the earthquake. The earthquake highlighted the complexity of frictional behaviors on the shallowest part of the subduction interface, previously regarded as mostly aseismic. Several pieces of evidence have been presented that illuminate the spatial correlation between the distribution of interplate faulting events of various sizes and time scales and associated structural heterogeneities. The stress re-distribution processes after the earthquake, including viscoelastic deformation and fluid remobilization, have been revealed both in the overriding and incoming plates and provide new insights in the dynamics of the subduction zone. Abundant records of the associated tsunami clarified various processes during the generation, propagation, and inundation of tsunamis. The earthquake also provides a unique opportunity to compare the fault model constrained by modern observations with those of past earthquakes based on geological records so that we can improve the reconstructed recurrence history of massive earthquakes. It is expected that a collection of research contributions regarding the Tohoku earthquake will benefit our general understanding regarding infrequent great (M > 9) subduction earthquakes.

In this special issue of SPEPS, we invite authors to contribute their latest research or reviews on the seismotectonics along the northeastern Japan margin from disciplinary and interdisciplinary viewpoints. The scope of this issue ranges across, but is not limited to, the diversity of fault behaviors along the plate boundary and its relation to structural heterogeneity of the plate boundary zone, postseismic deformation and seismicity, behavior of tsunamis, and earthquake geology and paleoseismology along the Japan trench.

Edited by: Takeshi Iinuma, Shuichi Kodaira, Masaki Yamada, Roland Bürgmann, Toru Matsuzawa, Ryota HINO