In the year 2000, an anomalous sequence of off-fault seismicity was detected near Lake Pillsbury in northern California. The seismicity was interpreted by Hayes et al. (2005, 2006) to be associated with a dike injection. I completed a gravity survey over the location of the seismicity and used that data in gravity modeling, to test the hypothesis that the seismicity was directly linked to the i...

The cause of intermediate-depth (> 40 km) seismicity in subduction zones is not well understood. The viability of proposed mechanisms, which include dehydration embrittlement, shear instabilities and the presence of fluids in general, depends significantly on local conditions, including pressure, temperature and composition. The wellinstrumented and well-studied subduction zone below Northern J...

A class of probability models for earthquake occurrences, called shortterm exciting, long-term correcting (SELC) models, is presented. This class encompasses features of two different classes of models presently used in hazard analysis to characterize earthquake catalogs: (1) self-exciting models and (2) self-correcting models. It offers the potential for a unified approach to the analysis and ...

[1] Earthquakes and the faults upon which they occur interact over a wide range of spatial and temporal scales. In addition, many aspects of regional seismicity appear to be stochastic both in space and time. However, within this complexity, there is considerable self-organization. We argue that the occurrence of earthquakes is a problem that can be attacked using the fundamentals of statistica...

Fracture and fault zones can channel fluid flow and transmit injection-induced pore pressure changes over large distances (>km), at which seismicity is rarely suspected to be human induced. We use seismicity analysis and hydrogeological models to examine the role of seismically active faults in inducing earthquakes. We analyze a potentially injection-induced earthquake swarm with three events a...

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....

One way to probe earthquake nucleation processes and the relation between stress buildup and seismicity is to analyze the sensitivity of seismicity to stress perturbations. Here, we report evidence for seasonal strain and stress (~2–4 kPa) variations in the Nepal Himalaya, induced by water storage variations which correlate with seasonal variations of seismicity. The seismicity rate is twice as...

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...