[1] To examine the effects of branched fault geometry on the dynamics of fault systems in the long term, we perform multicycle simulations on generic faulting models. An explicit finite element algorithm is used to simulate spontaneous dynamic rupture of earthquakes. The fault stress during the interseismic period is evaluated by an analytical viscoelastic model. We find that the fault prestres...

[1] Spatially averaged, absolute deviatoric stress tensors along the faults ruptured during the 2002 Denali fault earthquake, both before and after the event, are derived, using a new method, from estimates of the orientations of the principal stresses and the stress change associated with the earthquake. Stresses are estimated in three regions along the Denali fault, one of which also includes...

[1] We combine a viscoelastic model for the interseismic process and an elastodynamic model for the coseismic process to explore the dynamics (over multiple earthquake cycles) of two parallel strike-slip faults embedded in a two-dimensional full space. The step over fault geometry results in a buildup of heterogeneous fault stress near the step over. This heterogeneous stress accumulates at the...

We have investigated the possible cause-and-effect relationship due to stress transfer between two earthquakes that occurred near Christchurch, New Zealand, in September 2010 and in February 2011. The Mw 7.1 Darfield (Canterbury) event took place along a previously unrecognized fault. The Mw 6.3 Christchurch earthquake, generated by a thrust fault, occurred approximately five months later, 6 km...

The frictional resistance on a fault during slip controls earthquake dynamics. Friction dissipates heat during an earthquake; therefore, the fault temperature after an earthquake provides insight into the level of friction. The Japan Trench Fast Drilling Project (Integrated Ocean Drilling Program Expedition 343 and 343T) installed a borehole temperature observatory 16 months after the March 201...

The 1946 Aleutian earthquake was a typical tsunami earthquake which generated abnormally larger tsunami than expected from its seismic waves. Previously, Johnson and Satake (1997) estimated the fault model of this earthquake using the tsunami waveforms observed at tide gauges. However, they did not model the second pulse of the tsunami at Honolulu although that was much larger than the first pu...

Monitoring of earthquake faults and volcanoes contributes to our understanding of their dynamic mechanisms and to our ability to predict future earthquakes and volcanic activity. We report here on spatial and temporal variations of seismic velocity around the seismogenic fault of the 2016 Kumamoto earthquake [moment magnitude (Mw) 7.0] based on ambient seismic noise. Seismic velocity near the r...

The state-of-the-art of near-fault problems in earthquake engineering is comprehensive reviewed. Strong ground motions in the near-fault region exhibit several new characteristics, which cause the attentions of both seismologists and engineers who zealously studied these ground motions during the last two deceases. The investigation on ground motions can interpret the mechanism of the earthquak...

Repeated seismic surveys of the Landers, California, fault zone that ruptured in the magnitude (M) 7.5 earthquake of 1992 reveal an increase in seismic velocity with time. P, S, and fault zone trapped waves were excited by near-surface explosions in two locations in 1994 and 1996, and were recorded on two linear, three-component seismic arrays deployed across the Johnson Valley fault trace. The...

In 1995, the Hyogoken-Nanbu earthquake (M 7.3) ruptured the Nojima fault, Awaji Island, central Japan. To investigate the recovery process of a fault zone after a large earthquake, repeated water injection experiments have been conducted every few years in an 1800-m-long borehole near the Nojima fault since 1997. In addition, the groundwater discharge rate and pressure have been observed in an ...