Coseismic slip is observed to increase with earthquake rupture length for lengths far beyond the length scale set by the seismogenic layer. The observation, when interpreted within the realm of static dislocation theory and the imposed limit that slip be confined to the seismogenic layer, implies that earthquake stress drop increases as a function of rupture length for large earthquakes and, he...

Subduction earthquakes on plate-boundary megathrusts accommodate most of the global seismic moment release, frequently resulting in devastating damage by ground shaking and tsunamis. As many earthquakes occur in deep-sea regions, the dynamics of earthquake faulting in subduction zones is poorly understood. However, the Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Expe...

S U M M A R Y We present a statistical analysis of focal mechanism orientations for nine California fault zones with the goal of quantifying variations of fault zone heterogeneity at seismogenic depths. The focal mechanism data are generated from first motion polarities for earthquakes in the time period 1983–2004, magnitude range 0–5, and depth range 0–15 km. Only mechanisms with good quality ...

[1] We discuss numerical simulations of evolving fault zone structures in a 3-D lithospheric model with a seismogenic crust governed by a damage rheology that accounts for large strain associated with permanent brittle deformation. Results for the initial propagation of an existing narrow damage zone subjected to oblique loading exhibit strong asymmetry of the evolving damage with respect to th...

Seismogenic source zone models, including the delineation and characterization, still have a role to play in seismic hazard calculations, particularly regions with moderate or low seismicity. Seismic zones establish areas common tectonic characteristics, described by unique magnitude–frequency distribution. Their definition can be addressed from different views. Traditionally, been geographical...

Geophysical observations indicate that patches of localized fracturing occur within otherwise viscous regions subduction plate boundaries. These place uncertainty on the possible down-dip extent seismogenic zone, and as a result maximum magnitude thrust earthquakes. However, processes controlling where how occurs shear zones are unclear. We examined three exposures exhumed boundary Kyushu, Japa...

We demonstrate that great earthquakes occur predominantly in regions with a strongly negative trench-parallel gravity anomaly (TPGA), whereas regions with strongly positive TPGA are relatively aseismic. These observations suggest that, over time scales up to at least 1 million years, spatial variations of seismogenic behavior within a given subduction zone are stationary and linked to the geolo...

Y. Hashimoto 1 , O. Tadai 2 , M. Tanimizu 3 , W. Tanikawa 3 , T. Hirono 4 , K. Aoike 5 , T. Ishikawa 3 , M. Murayama 6 , W. Soh 3 , S. R. Song 7 , K. Fujimoto 8 , T. Fukuchi 9 , M. Ikehara 6 , H. Ito 4 , H. Kikuta 3 , M. Kinoshita 10 , W. Lin 3 , K. Masuda 11 , T. Matsubara 9 , O. Matsubayashi 12 , T. Mishima 6 , K. Mizoguchi 13 , N. Nakamura 14 , K. Otsuki 14 , M. Sakaguchi 2 , T. Shimamoto 15...