The 1999 Chi-Chi earthquake (MW=7.6; ML=7.3) ruptured in an area considered unusual in that, historically, large earthquakes have been unheard of and the background seismicity are low. A detailed investigation of the crustal characteristics based on seismicity, subsurface structures and GPS surveys shows that crustal strength in the low-seismicity block was most likely stronger than in the surr...

The observation of foreshocks preceding large earthquakes and the suggestion that foreshocks have specific properties that may be used to distinguish them from other earthquakes have raised the hope that large earthquakes may be predictable. Among proposed anomalous properties are the larger proportion than normal of large versus small foreshocks, the power law acceleration of seismicity rate a...

Using the technique developed by Newman and Okal [J. Geophys. Res. 103 (1998) 26885], a dataset of digital records from 84 earthquakes is analyzed to investigate their source slowness in the quest for a possible regional signal in three subduction zones which experienced recent tsunami earthquakes (Nicaragua, 1992; Java, 1994; Peru, 1996). The dataset is augmented by analog seismograms from his...

Earthquakes are one of the most destructive natural hazards on our planet Earth. Hugh earthquakes striking offshore may cause devastating tsunamis, as evidenced by the 11 March 2011 Japan (moment magnitude Mw 9.0) and the 26 December 2004 Sumatra (Mw 9.1) earthquakes. Earthquake prediction (in terms of the precise time, place, and magnitude of a coming earthquake) is arguably unfeasible in the ...

In this study, I consider the ground motions generated by 11 moderate (Mw 4.0–5.6) earthquakes in the central and eastern United States that are thought or suspected to be induced by fluid injection. Using spatially rich intensity data from the U.S. Geological Survey “Did You Feel It?” system, I show the distance decay of intensities for all events is consistent with that observed for tectonic ...

We report precursory seismic patterns prior to the 2016 Kumamoto earthquakes, as measured by four different methods based on changes in seismicity that can be used for earthquake forecasting: the b-value method, two methods of seismic quiescence evaluation, and an analysis of seismicity density in space and time. The spatial extent of precursory patterns differs from one method to the other and...

considering recent developments in earthquake engineering, researchers has detected different effects of earthquakes far and near from the fault. investigations that have been done in this area show that near fault earthquakes have shorter time period comparing far fault earthquakes and in the velocity of near fault earthquakes, there are one or more impacting pulses with a big domain and perio...

Slow-slip events, or ‘silent earthquakes’, have recently been discovered in a number of subduction zones including the Nankai trough in Japan, Cascadia, and Guerrero in Mexico, but the depths of these events have been difficult to determine from surface deformation measurements. Although it is assumed that these silent earthquakes are located along the plate megathrust, this has not been proved...

Earthquake occurrence in nature is thought to result from correlated elastic stresses, leading to clustering in space and time. We show that the occurrence of major earthquakes in California correlates with time intervals when fluctuations in small earthquakes are suppressed relative to the long term average. We estimate a probability of less than 1% that this coincidence is due to random clust...

Analysis of the tidal stress tensor at the time of moderate to large earthquakes fails to confirm an earlier hypothesis that the origin times of shallow dip-slip earthquakes correlate with solid-earth tidal shear stress, Furthermore, no correlation is seen for either tidal shear stress or tidal normal-to-the-fault compressive stress with shallow strike-slip earthquakes or with deep earthquakes....