We have developed a method to detect long-period precursors for large earthquakes observed in southern California, if they occur. The method allows us to continuously monitor seismic energy radiation over a wide frequency band to investigate slow deformation in the crust (e.g., slow earthquakes), especially before large earthquakes. We used the long-period records (1 sample/sec) from TERRAscope...

This study is based on a data set of aftershocks (location, fault−plane solutions) following the M=5.1 Arudy earthquake (02/29/80, French Western Pyrenees), and complementary geomorphological data (virtual geology using DEM and aerial photography). Data processing using Geophysical Information System are combined with identification of multi−structures based on the anisotropic wavelet formalism...

Abstract Coseismic rotations of principal stress axes can provide insights into the strength crust, but it is unclear how common this phenomenon is. We use a nearest‐neighbor clustering algorithm to identify earthquake sequences in global ISC‐GEM catalog and regional Southern California catalog. Using an inner‐product‐based pairwise measure moment tensor similarity, we demonstrate that, both ca...

Strong crustal earthquakes in Greece are typically followed by aftershocks, the properties of which important factors seismic hazard assessment. In order to examine earthquake sequences, we prepared an catalog comprising aftershock sequences with mainshocks Mw ≥ 5.5 from 1995 2021. Regional parameters were estimated highlight variations decay and productivity among regions similar seismotectoni...

Long-period strong motions (> 0.9 second) are simulated in the Kobe area for the mainshock (1/17/95) and the aftershock (2/2/95) of the Hyogoken-Nanbu (Kobe) earthquake. In order to model ground motions in the realistic and highly heterogeneous basin structure, an unstructured 3D FEM (Finite Element Method) is used, which runs efficiently on parallel computers. The simulation results show stron...

[1] Data collected from the 2003 Mw6.5 San Simeon earthquake sequence in central California and a 1986 seismic refraction experiment demonstrate that the weak Franciscan subduction complex suffered brittle failure in a region without significant velocity contrast across a slip plane. Relocated hypocenters suggest a spatial relationship between the seismicity and the Oceanic fault, although blin...

We propose a new physically-based “multifractal stress activation” model of earthquake interaction and triggering based on two simple ingredients: (i) a seismic rupture results from activated processes giving an exponential dependence on the local stress; (ii) the stress relaxation has a long memory. The combination of these two effects predicts in a rather general way that seismic decay rates ...