Small transient stress perturbations are prone to trigger (micro)seismicity. In the Earth’s crust, these can be caused by various sources such as passage of seismic waves, forcing tides, or hydrological seasonal loads. A better understanding dynamic earthquake triggering is essential improve our physics and consideration hazard. Here, we study an experimental sandstone-gouge-filled fault system...

[1] Abstract: The subducting Nazca Plate shows a high degree of along-strike heterogeneity in terms of intermediate-depth seismicity ( 70–300 km), orientations of slab stress, and volcanism. We compile the intermediate-depth earthquakes of South America from the Harvard Centroid Moment Tensor (CMT) catalogue to determine along-strike dip variations, and we explore the variable level of correlat...

Thermal perturbation of mantle phase relations in subduction zones gives rise to significant buoyancy anomalies. Finite element modeling of stresses arising from these anomalies reveals transition from principal tension to compression near ∼400 km depth, down-dip compression over ∼400-690 km (peaking at ∼550 km), and transition to rapidly fading tension below ∼690 km. Such features, even when c...

Earthquake aftershock identification is closely related to the question “Are aftershocks different from the rest of earthquakes?” We give a positive answer to this question and introduce a general statistical procedure for clustering analysis of seismicity that can be used, in particular, for aftershock detection. The proposed approach expands the analysis of Baiesi and Paczuski [PRE, 69, 06610...

We estimate the rate of aftershocks triggered by a heterogeneous stress change, using the rate-and-state model of Dieterich [1994]. We show that an exponential stress distribution Pτ (τ) ∼ exp(−τ/τ0) gives an Omori law decay of aftershocks with time ∼ 1/t, with an exponent p = 1− Aσn/τ0, where A is a parameter of the rate-and-state friction law, and σn the normal stress. Omori exponent p thus d...

The ongoing, dramatic increase in seismicity in the central United States that began in 2009 is believed to be the result of injection-induced seismicity (Ellsworth, 2013). Although the basic mechanism for activation of slip on a fault by subsurface fluid injection is well established (Healy et al., 1968; Raleigh et al., 1976; Nicholson and Wesson, 1992; McGarr et al., 2002; Ellsworth, 2013), t...

Abstract The clearest statistical signal in aftershock locations is that most aftershocks occur close to their mainshocks. More precisely, are triggered at distances following a power-law decay distance (Felzer and Brodsky, 2006). This kernel used epidemic-type sequence (ETAS) modeling typically assumed be isotropic, even though individual sequences show more clustered occurrence. assumption of...

This work reviews some results obtained already for the variations of the seismicity parameters b and p in different seismogenic and tectonic regions in Japan. We bring as well new evidence that the time and space changes in seismicity parameters are correlating well with the crustal structure and/or some parameters of the earthquake process. In the first part of the paper we show that several ...

A previous attempt to integrate geological, geodetic, and observed seismicity data into a probabilistic-hazard source model predicted a rate of magnitude 6 to 7 earthquakes significantly greater than that observed historically. One explanation was that the discrepancy, or apparent earthquake deficit, is an artifact of the upper magnitude limit built into the model. This was controversial, howev...