To assess whether recent seismicity is induced by human activity or is of natural origin, we analyze fault displacements on high-resolution seismic reflection profiles for two regions in the central United States (CUS): the Fort Worth Basin (FWB) of Texas and the northern Mississippi embayment (NME). Since 2009, earthquake activity in the CUS has increased markedly, and numerous publications su...

[1] We use recent results on statistical analysis of seismicity to present a robust method for comprehensive detection and analysis of earthquake clusters. The method is based on nearest-neighbor distances of events in space-time-energy domain. The method is applied to a 1981–2011 relocated seismicity catalog of southern California having 111,981 events with magnitudes m ≥ 2 and corresponding s...

[1] For the period 1995–2000, the Nepal seismic network recorded 37 ± 8% fewer earthquakes in the summer than in the winter; for local magnitudes ML > 2 to ML > 4 the percentage increases from 31% to 63% respectively. We show the probability of observing this by chance is less than 1%. We find that most surface loading phenomena are either too small, or have the wrong polarity to enhance winter...

We analyzed seismicity linked to the 2014 phreatic eruption of Mount Ontake, Japan, on 27 September 2014. We first relocated shallow volcano tectonic (VT) earthquakes and long-period (LP) events from August to September 2014. By applying a matched-filter technique to continuous waveforms using these relocated earthquakes, we detected numerous additional micro-earthquakes beneath the craters. Th...

A model of the spatial and temporal distribution of seismicity both before and after the Northridge, California earthquake has been used to estimate the background stress state, loading rate, and some parameters relating to fault friction. A detailed source model was used to calculate the stress change eld from the Northridge mainshock, which 1 was t to the spatial distribution of seismicity. A...

Historically, seismicity documented in the Western Canada Sedimentary Basin has been relatively quiescent and earthquakes are usually restricted to the foreland belt of the Rocky Mountains. However, exceptional clusters of events, which have remained active for decades, are recognized in Alberta. In this study we investigate the seismicity in this region using data obtained from recently establ...

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 ...

EARTHQUAKE SOURCE PARAMETERS, SEISMICITY, AND TECTONICS OF THE OCEANOGRAPHER TRANSFORM FAULT

[1] We investigate seismicity near faults in the Southern California Earthquake Center Community Fault Model. We search for anomalously large events that might be signs of a characteristic earthquake distribution. We find that seismicity near major fault zones in Southern California is well modeled by a Gutenberg-Richter distribution, with no evidence of characteristic earthquakes within the re...

A probabilistic seismic hazard assessment in terms of Arias intensity is presented for the city of Tehran. Tehran is the capital and the most populated city of Iran. From economical, political and social points of view, Tehran is the most significant city of Iran. Many destructive earthquakes happened in Iran in the last centuries. Historical references indicate that the old city of Rey and the...