Based on waveform data from a profile of aftershocks following the north-south trace of the 28 June 1992 Landers rupture across the Mojave desert, we construct a new velocity model for the Mojave region that features a thin, slow crust. Using this model, we obtain source parameters, including depth and duration, for each of the aftershocks in the profile and, in addition, any significant (M > 3...

A structure may be subject to several aftershocks after a mainshock. In many seismic design provisions, the effect of sequences is either not directly considered or has been underestimated. This study examined behavior reinforced concrete (RC) moment-resisting structures with shear walls under sequences. Two three-dimensional short and medium height were designed analyzed seven real mainshock–a...

Earthquakes are usually clustered in both time and space and, within each cluster, the event of highest magnitude is conventionally identified as mainshock, while foreshocks aftershocks events that occur before after it, respectively. Mainshocks earthquakes considered classical formulation probabilistic seismic hazard analysis (PSHA), where contribution neglected. In fact, it has been shown pos...

As part of an effort to develop a systematic methodology for earthquake forecasts, we use a simple model of seismicity based on interacting events which may trigger a cascade of earthquakes, well-known as the Epidemic-Type Aftershock Sequence model). The ETAS model is constructed on a (bare) Omori’s law, the Gutenberg-Richter law and the idea that large events trigger more numerous aftershocks....

Abstract Moderate-to-large-magnitude earthquakes induce considerable short-to-medium-term increases in seismic hazard, due to the subsequent occurrence of aftershocks. Most studies on aftershock models focus their performance as part Operational Earthquake Forecasting (i.e., real- or near-real-time predictions ongoing sequences). Aftershock model validation a longer timescale is scarcely dealt ...

Abstract Earthquake occurrences are often described using a class of branching models called Epidemic-Type Aftershock Sequence (ETAS) models. The name derives from the fact that the model allows earthquakes to cause aftershocks, and then those aftershocks may induce subsequent aftershocks, and so on. Despite their value in seismology, such models have not previously been used in studying the in...

Abstract Earthquake occurrences are often described using a class of branching models called Epidemic-Type Aftershock Sequence (ETAS) models. The name derives from the fact that the model allows earthquakes to cause aftershocks, and then those aftershocks may induce subsequent aftershocks, and so on. Despite their value in seismology, such models have not previously been used in studying the in...

[1] We analyze the seismicity rate immediately after the 2004 Mw6.0 Parkfield, California, earthquake from nearsource seismograms. By scrutinizing high-frequency signals, we can distinguish mainshock coda from early aftershocks occurring as soon as 30 s after the mainshock. We find, as expected, that a significant fraction of aftershocks in the first few hours after the main shock are missing i...

By combining direct imaging and acoustic emission measurements, the subcritical propagation of a crack in a heterogeneous material is analyzed. Both methods show that the fracture proceeds through a succession of discrete events. However, the macroscopic opening of the fracture captured by the images results from the accumulation of more-elementary events detected by the acoustics. When the aco...