Ionospheric perturbations in plasma parameters have been observed before large earthquakes, but the correlation between different parameters has been less studied in previous research. The present study is focused on the relationship between electron density (Ne) and temperature (Te) observed by the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite ...

[1] Some of the largest and most anomalous volcanic earthquakes have non-double-couple focal mechanisms. Here, we investigate the link between volcanic unrest and the occurrence of non-double-couple earthquakes with dominant vertical tension or pressure axes, known as vertical compensated-linear-vector-dipole (vertical-CLVD) earthquakes. We determine focal mechanisms for 313 target earthquakes ...

Data from 10,126 earthquakes that occurred in the southern California region between 1934 and 1963 have been synthesized in the attempt to understand better their relationship to regional geologic structure, which is here dominated by a system of faults related mainly to the San Andreas system. Most of these faults have been considered "active" from physiographic evidence, but both geologic and...

Postseismic slip observed after large (M> 6) earthquakes typically has an equivalent moment of a few tens of percent of the coseismic moment. Some observations of the recurrence intervals of repeating earthquakes suggest that postseismic slip following small (M ≲ 4) earthquakes could be much larger—up to 10 or 100 times the coseismic moment. We use borehole strain data from U.S. Geological Surv...

Operational earthquake forecasting in the Uniform California Earthquake Rupture Forecast, version 3 (UCERF3) model will be implemented using the Epidemic Type Aftershock Sequence (ETAS) model. Parameter values for the ETAS model are determined by fitting that model to the recent instrumental earthquake catalog. A grid search is done, and the loglikelihood is used as a measure of fit to estimate...

We show that the spatial heterogeneity in the coseismic displacement of large earthquakes likely reflects the spatial characteristics of the frictional properties and that it can be inferred from the stress drop of moderate-sized earthquakes. We analyzed stress drops of 686 earthquakes with magnitudes of 4.0 to 5.0 off the south-east of Hokkaido, Japan, and investigated the spatial heterogeneit...

[1] Triggered earthquakes can be large, damaging, and lethal as evidenced by the1999 shocks in Turkey and the 2001 earthquakes in El Salvador. In this study, earthquakes with Ms 7.0 from the Harvard centroid moment tensor (CMT) catalog are modeled as dislocations to calculate shear stress changes on subsequent earthquake rupture planes near enough to be affected. About 61% of earthquakes that o...

[1] The activity at Mauna Loa volcano, Hawaii, is characterized by eruptive fissures that propagate into the Southwest Rift Zone (SWRZ) or into the Northeast Rift Zone (NERZ) and by large earthquakes at the basal decollement fault. In this paper we examine the historic eruption and earthquake catalogues, and we test the hypothesis that the events are interconnected in time and space. Earthquake...

The recurrence intervals of repeating earthquakes on the San Andreas Fault in the Loma Prieta aftershock zone follow the characteristic 1/t decay of Omori’s law. A model in which these earthquakes occur on isolated patches of the fault that fail in stick-slip with creep around them can explain this observation. In this model the recurrence interval is inversely proportional to the loading rate ...