in this study, the 2005 dahuieh (zarand) locally recorded aftershock sequence has been analyzed. having the distribution of aftershocks and the source extension, a w-e trending near vertical faulting with an extension of about 15-20 km could be estimated. the rupture causing the powerful dahuieh earthquake apparently initiated in the modified epicentric area and propagated unilaterally towards ...

[1] The recurrence intervals for 194 repeating clusters on the Calaveras fault follow a power-law decay relation with elapsed time after the 1984 M6.2 Morgan Hill, California, mainshock. The decay rates of repeating aftershocks in the immediate vicinity of a high-slip patch that failed during the mainshock systematically exceed those that are farther away. The trend between relative moment and ...

The observed seismicity rate increase after large earthquakes in sites that are located several source lengths away from the mainshock centroid poses a major problem. This is because the static stress change induced by a mainshock in that region seems to be insignificant, and the dynamic stress changes can only enhance the seismicity during the passage of the seismic waves but not at later time...

Broadband, large dynamic range GEOS data from four aftershocks (M L 2 to 3) of the 1983 Goodnow, New York, earthquake, recorded at hard-rock sites 2 to 7 km away from the epicentral area, are used to study rupture processes of three larger events, with an M L = 1.6 event as the Green's function event. We analyze the spectra and spectral ratios of ground velocity at frequencies up to 100 Hz, and...

Tectonic implications of subcrustal, normal faulting earthquakes in the western Shikoku region have been investigated in sorme detail, mainly based on the faulting mechanism of the Bungo channel earthquake of August 6, 1968 (M=6.6, h=45km) and its aftershocks. A synthetic study of the focal mechanism solution, spatial distribution of aftershocks, seismic waves observed in the near and far field...

The devastating earthquake (and the corresponding tsunami) that struck the Indian Ocean near Sumatra (Indonesia) on 26 December, 2004 was extremely powerful. In the present study, a very high resolution 3D gravity image has been generated over a part of eastern Indian offshore over the Sumatran earthquake region. Four latitudinal gravity profiles have been generated across the epicenter/aftersh...

Abstract For decades there has been a debate about the relative effects of dynamic versus static stress triggering aftershocks. According to Coulomb change hypothesis, aftershocks should not occur in shadows—regions where reduced. We show that shadows substantially influence aftershock occurrence following three M ? 7 California mainshocks. Within modeled shadows, rate is an order magnitude low...

The physics of earthquake triggering together with simple assumptions of self-similarity impose the existence of a minimum magnitude m0 below which earthquakes do not trigger other earthquakes. Noting that the magnitude md of completeness of seismic catalogs has no reason to be the same as the magnitude m0 of the smallest triggering earthquake, we use quantitative fits and maximum likelihood in...