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 ...

Basic Quantities from Earthquake Records Earthquakes are complex, dynamic events. In order to describe and work with them, a vocabulary of terms is necessary. Terms describing the intensity or magnitude of an earthquake give the engineer a quick estimate of the degree of shaking and damage one would expect. Other values reflect the time history of the earthquake such as acceleration, velocity, ...

Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitou...

In this paper, the probable range of the horizontal component of peak ground acceleration (PGA) is predicted as a function of focal depth, earthquake magnitude and epicentral distance, using artificial neural network (ANN). Three different ANN architectures (namely Feed Forward, Back Propagation and Radial Bias Networks) are used to develop the model. The three models are then compared, to deci...

There is anecdotal evidence for profound behavioral changes prior to and during earthquakes in many organisms, including arthropods such as ants. Behavioral or physiological analysis has often, in light of these reports, been proposed as a means of earthquake prediction. We report here a serendipitous study of the effect of the powerful Landers earthquake in the Mojave Desert, USA (Richter magn...

an earthquake with magnitude ms = 6.5 on the richter scale occurred in december 26th, 2003 in bam region in southeastern part of iran. this study investigates the chemical variations of the groundwater resources in the effected region. for this purpose, 30 wells were selected and chemical compounds, in terms of cations (ca+2, mg+2, na+, k+); anions (hco3, so4, cl, no2), as well as ec, tds and p...

Seismic tomography revealed a low seismic velocity (-5%) and high Poisson's ratio (+6%) anomaly covering about 300 square kilometers at the hypocenter of the 17 January 1995, magnitude 7.2, Kobe earthquake in Japan. This anomaly may be due to an overpressurized, fluid-filled, fractured rock matrix that contributed to the initiation of the Kobe earthquake.

The 26 March 1872 Owens Valley earthquake is among the largest historical earthquakes in California. The felt area and maximum fault displacements have long been regarded as comparable to, if not greater than, those of the great San Andreas fault earthquakes of 1857 and 1906, but mapped surface ruptures of the latter two events were 2–3 times longer than that inferred for the 1872 rupture. The ...

The nationwide strong-motion seismograph network of K-NET and KiK-net in Japan successfully recorded the strong ground motions of the 2016 Kumamoto earthquake sequence, which show the several notable characteristics. For the first large earthquake with a JMA magnitude of 6.5 (21:26, April 14, 2016, JST), the large strong motions are concentrated near the epicenter and the strong-motion attenuat...

The quest to find successful methods to forecast future earthquakes has proven to be very challenging. Useful earthquake forecasts require detailed specification of a number of variables, namely the epicenter, depth, time and magnitude of the coming earthquake. While forecasting the times of strong aftershocks within the rupture zone of a strong earthquake has been developed with some success (...