Abstract Following observations made in a survey campaign along the Lost River Fault (Idaho, USA) 2019, we integrate both original and previously published data to obtain detailed segmentation of fault sections that failed 1983 Borah Peak earthquake (Mw 6.9). The ruptured topographic surface with an oblique-normal faulting mechanism, activating two SW-dipping segments (Thousand Springs Warm Spr...

Geological forces shape the earth’s crust. Normal faults, for example, form when extensional forces pull blocks of rock apart along a plane, whereas reverse faults are formed by compressional forces. Geologists classify faults to retrace the forces that have acted on an area; however, normal and reverse faults often look similar. In this study we investigated whether viewing superficially simil...

Offshore structures such as jacket platforms have to inevitably be designed against  sever  environmental actions. In seismically active areas these structures also become susceptible to earthquake excitations. Strong ground motions recorded  in recent earthquakes, including the 1995 Kobe, Japan, 1999 Chi-chi, Taiwan and 1999 Kocaeli, Turkey earthquakes, revealed that the dynamic motions in nea...

18 The 2012 M8.6 off-Sumatra earthquake, the largest strike-slip and intraplate earthquake recorded 19 to date, followed an exceptionally tortuous rupture path. It featured two episodes of branching 20 into fault segments that were experiencing increased compressive dynamic stresses, hence 21 increased frictional strength. Meng et al. (2012) attributed this unexpected compressional 22 branching...

Twelve three-component strong-motion displacement records are modeled for the 1979 Imperial Valley earthquake to recover the distribution of slip on the lmperral fault plane. The final model, for which point source responses are calculated by a discrete wavenumber /finite element technique, uses a structure with gradients in material properties rather than layers. The effects of a velocity grad...

the near field ground motions have a high amplitude pulse like at the beginning of the seismogram which are significantly influenced by the rupture mechanism and direction of rupture propagation. this type of ground motion cause higher demands for engineering structures and its response spectrum is dramatically different than far field spectra. tabriz is one of the ancient cities in azerbaijan ...

A primary goal in seismology is to identify constraints arising from the small scale physics of friction and fracture that can provide bounds on seismic hazard and ground motion at the fault scale. Here we review the multi-scale earthquake rupture problem and describe a physical model for the deformation of amorphous materials such as granular fault gouge. The model is based on Shear Transforma...

[1] Fault zone structure and properties may contain important information about past earthquake rupture and subsequent healing processes. Damaged fault zones are observed geologically in the field [e.g., Chester and Chester, 1998; Ben-Zion and Sammis, 2003]. Seismic studies have revealed the existence of low-velocity fault zones around active faults [e.g., Li et al., 1998; Ben-Zion et al., 2003...

We deployed a dense linear array of 45 seismometers across and along the San Andreas fault near Parkfield a week after the M 6.0 Parkfield earthquake on 28 September 2004 to record fault-zone seismic waves generated by aftershocks and explosions. Seismic stations and explosions were co-sited with our previous experiment conducted in 2002. The data from repeated shots detonated in the fall of 20...

Seismological observations of the 2012 moment magnitude 8.6 Sumatra earthquake reveal unprecedented complexity of dynamic rupture. The surprisingly large magnitude results from the combination of deep extent, high stress drop, and rupture of multiple faults. Back-projection source imaging indicates that the rupture occurred on distinct planes in an orthogonal conjugate fault system, with relati...