[1] We analyze seismicity rate immediately before and after 82 main shocks with the magnitudes ranging from 3 to 5 using waveforms recorded by the Hi-net borehole array in Japan. By scrutinizing high-frequency signals, we detect 5 times as many aftershocks in the first 200 s as in the Japan Meteorological Agency catalogue. After correcting for the changing completeness level immediately after t...

Remote dynamic triggering occurred in the western United States and Greece following the following the Denali, Hector Mine, Landers, and Izmit mainshocks in seismically active, largely geothermal areas that experienced shaking from the mainshock typically exceeding 0.2 cm/sec. Because triggered earthquakes are small (often below Mw, 2), investigations of whether remote triggering is a generally...

The paper describes a method for using regional seismic data based on processing the results of experiments carried out tiltmeter to study dangerous conditions and clarify structural boundaries lithospheric units in region. use experimental methods will make it possible determine true parameters block structure, which are necessary practical application element seismicity.

[1] We synthesize the tectonics of the southern Walker Lane belt and Coso Range in central eastern California using regional earthquake data. First, we invert for threedimensional models of the Vp and Vp /Vs structure of the upper and middle crust. Using these models, we also determine three-dimensional Vs and Poisson’s ratio models. The changes in seismic velocities across the region are small...

[1] Over 109 small earthquakes (Mw 0.4–3.9) were detected during January 2011 to February 2012 in the Youngstown, Ohio area, where there were no known earthquakes in the past. These shocks were close to a deep fluid injection well. The 14 month seismicity included six felt earthquakes and culminated with aMw 3.9 shock on 31 December 2011. Among the 109 shocks, 12 events greater than Mw 1.8 were...

The spatial-temporal pattern of seismicity, preceding 5 moderate-sized earthquakes with MD ≥ 4.1, that occurred in the Friuli-Venezia Giulia region (northeastern Italy) and in western Slovenia, is investigated with the Region-Time-Length (RTL) and the PI algorithms. These algorithms were originally formulated to reveal the variation of seismicity patterns before large earthquakes. The RTL algor...

High-resolution magnetotelluric (MT) studies of the San Andreas fault (SAF) near Hollister, CA have imaged a zone of high fluid content flanking the San Andreas fault and extending to midcrustal depths. This zone, extending northeastward to the Calaveras fault, is imaged as several focused regions of high conductivity, believed to be the expression of tectonically bound fluid pockets separated ...

Three large earthquakes occurred in the Gulf of Alask• during 1987-1988: one on November 17, 1987 (Mw = 7.2), the second one on November 30, 1987 (Mw = 7.8), and the third one on March 6, 1988 (Mw = 7.7). These major intraplate, strike-slip oceanic events occurred along conjugate trends in a region of no previous seismicity. Body wave modeling places their centroid depths in the upper mantle. T...

Subducted oceanic metabasalts are believed to be a primary source of volatiles for arc magmatism and fluid-induced seismicity. From phase equilibria computed for an average oceanic metabasalt we present a model for subduction zone devolatilization for pressures up to 6 GPa (V180 km). Along high temperature geotherms complete dehydration occurs under forearcs, whereas dehydration does not occur ...

SUMMARY Occurrence of seismicity sequences as consequence fluid injection or extraction has long been studied and documented. Causal relations between parameters, such pressure, rates, total injected volumes injectivity, with derived rate, cumulative seismic moment, distance (RT-plot), b-values, etc. have derived. In addition, reservoir engineering parameters permeability/porosity flow types pl...