15 In order to reproduce slow earthquakes with short duration such as very low 16 frequency events (VLFs) migrating along the trench direction as swarms, we apply a 17 3-D subduction plate boundary model based on the slowness law of rate-and 18 2 state-dependent friction, introducing close-set numerous small asperities 1 (rate-weakening regions) at a depth of 30 km under high pore pressure cond...

[1] Subducted seamounts have been linked to interplate earthquakes, but their specific effects on earthquake mechanism remain controversial. A key question is under what conditions a subducted seamount will generate or stop megathrust earthquakes. Here we show results from numerical experiments in the framework of rateand state-dependent friction law in which a seamount is characterized as a pa...

U the physics of complex phenomena such as earthquakes is a formidable challenge. Because we are constrained by our inability to do experiments on earthquake faults, we turn to computers as our earthquake laboratories. Computer simulations of earthquakes help us to test theoretical models and allow us to generate catalogs of synthetic earthquake events. In this column, we discuss several models...

[1] We present a new crustal seismic velocity model for southern California derived from P and S arrival times from local earthquakes and explosions. To reduce the volume of data and ensure a more uniform source distribution, we compute ‘‘composite event’’ picks for 2597 distributed master events that include pick information for other events within spheres of 2 km radius. The approach reduces ...

Developing countries lacking technology infrastructures experience most disasters such as tsunami, hurricane Katrina, earthquakes. Even though, many lives are saved in developed countries through the use of high-level or sophisticated technology, only the technology that is easy to use, inexpensive, durable and field-tested should be introduced and used during the relief operation. The effect o...

Earthquakes triggered by other remote seismic events are explained as a response to long-traveling seismic waves that temporarily stress the crust. However, delays of hours or days after seismic waves pass through are reported by several studies, which are difficult to reconcile with the transient stresses imparted by seismic waves. We show that these delays are proportional to magnitude and th...

The recent deployment of many seismometers and occurrences of earthquakes in Japan revealed explosive nature of earthquakes. There have been a few reports that earthquakes and eruption of helium gas took place simultaneously, but there has been no hypothesis to co-relate each other. Recently, a new idea that atomic hydrogen can generate energy somewhat between chemical reaction and nuclear reac...

We analyzed the historical seismicity in southern California to develop a rational approach for calculating the seismic hazard from background seismicity of magnitude 6.5 or smaller. The basic assumption for the approach is that future earthquakes will be clustered spatially near locations of historical mainshocks of magnitudes equal to or greater than 4. We analyzed the declustered California ...

The Mw 7.9 Denali fault earthquake in central Alaska of 3 November 2002 triggered earthquakes across western North America at epicentral distances of up to at least 3660 km. We describe the spatial and temporal development of triggered activity in California and the Pacific Northwest, focusing on Mount Rainier, the Geysers geothermal field, the Long Valley caldera, and the Coso geothermal field...

Evidence suggests that slip in earthquakes and the resultant stress changes are spatially heterogeneous. If crustal stress from past earthquakes is spatially heterogeneous, then earthquake focal mechanisms should also be spatially variable. We describe the statistical attributes of simulated earthquake catalogs, including hypocenters and focal mechanisms, for a spatially 3D, time-varying model ...