S U M M A R Y Motivated by a recent resurgence in earthquake predictability research, we present a method for testing alarm-based earthquake predictions. The testing method is based on the Molchan diagram—a plot of miss rate and fraction of space–time occupied by alarm—and is applicable to a wide class of predictions, including probabilistic earthquake forecasts varying in space, time, and magn...

[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...

The standard model of injection-induced seismicity considers changes in Coulomb strength due solely to changes in pore pressure. We consider two additional effects: full poroelastic coupling of stress and pore pressure, and time-dependent earthquake nucleation. We model stress and pore pressure due to specified injection rate in a homogeneous, poroelastic medium. Stress and pore pressure are us...

Using the simple ETAS branching model of seismicity, which assumes that each earthquake can trigger other earthquakes, we quantify the role played by the cascade of triggered seismicity in controlling the rate of aftershock decay as well as the overall level of seismicity in the presence of a constant external seismicity source. We show that, in this model, the fraction of earthquakes in the po...

Stress focusing in a proposed heel-shaped model reasonably explains the occurrence of the largest onland earthquake (MW 7.6) in Taiwan’s history. The epicenter of the mainshock was located in a low-seismicity block, where, historically, large earthquakes have not been documented for the past century. Spatial variations in crustal deformation reported in Global Positioning System surveys suggest...

Changes in seismicity rates, whether of tectonic or of induced origin, can readily be identified in regions where background rates are low but are difficult to detect in seismically active regions. We present a novel method to identify likely induced seismicity in tectonically active regions based on short-range spatiotemporal correlations between changes in fluid injection and seismicity rates...

Mature seismic gaps are defined here as gaps in which a possible precursor to a future event has been identified. The seismic potential of these seismic gaps is enhanced relative to immature seismic gaps. The seismic gap hypothesis by itself provides an excellent means of narrowing spatial limits along plate boundaries within which the great earthquakes of the next several decades are expected....

Recent studies of reservoir-induced seismicity have led to a better understanding of the seismogenic crust. These studies reveal that many parts of the seismogenic crust are critically stressed and small strength changes induced by reservoir impoundment can lead to seismicity. In the vicinity of the reservoir impoundment causes an immediate undrained response to the loading, and a delayed respo...

Background Gaucher et al. (2015) provide an overview on published methods employed for modelling induced seismicity in geothermal reservoirs. Here I focus exclusively on the rateand state-dependent theory of Dieterich (1994), further referred to as RST for modelling fluid injection induced seismicity. For simplicity, I consider the case of fluid injection at the origin in a medium with isotropi...

The Cellular Seismology (CS) method of Kafka (2002, 2007) is presented as a leastastonishing null hypothesis that serves as a useful standard of comparison for other, more complex, spatial forecast methods (i.e., methods that forecast the locations, but not the times, of earthquakes). Spatial forecast methods based on analyses of earthquakes in California such as that of Ebel et al. (2007) and ...