The moment magnitude (Mw) 7.9 Fort Tejon earthquake of 1857, with a approximately 350-kilometer-long surface rupture, was the most recent major earthquake along the south-central San Andreas Fault, California. Based on previous measurements of its surface slip distribution, rupture along the approximately 60-kilometer-long Carrizo segment was thought to control the recurrence of 1857-like earth...

Coseismic deformation fields of the 6 October 2008 Mw6.3 Damxung earthquake were obtained from interferometric synthetic aperture radar by using three descending and two ascending Envisat images. Significant coseismic surface deformation occurred within 20 km 9 20 km of the epicenter with a maximum displacement of *0.3 m along the satellite line of sight. We model a linear elastic dislocation i...

Understanding variations of slip distance along major thrust systems at convergent margins is an important issue for evaluation of near-trench slip and the potential generation of large tsunamis. We derived quantitative estimates of slip along ancient subduction fault systems by using the maturity of carbonaceous material (CM) of discrete slip zones as a proxy for temperature. We first obtained...

We consider the nucleation of instability on a slip-weakening fault subjected to a heterogeneous, locally peaked “loading” stress. That stress is assumed to gradually increase due to tectonic loading but to retain its peaked character. The case of a linear stress versus slip law is considered in the framework of two-dimensional quasi-static elasticity for a planar fault. Slip initiates when the...

The near-source energy released on a fault is estimated through the strain energy change and the fracture energy from the results of kinematic waveform inversion and dynamic modeling for two different types of earthquakes: a shallow crustal earthquake, the 2000 Tottori, Japan (Mw 6.6) earthquake, and an in-slab event, the 1999 Oaxaca, Mexico (Mw 7.5) earthquake. The procedure incorporates the s...

On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth's surface. We then propose a four-segmented f...

[1] We perform two-dimensional dynamic models of strike-slip faults with a change in strike (a bend) over multiple earthquake cycles to examine the long-term effects of nonplanar fault geometry. A viscoelastic model (a proxy for off-fault deformation and tectonic loading) is introduced for the interseismic process to avoid pathological stress buildup around the bend. A finite element method wit...

Fluid overpressure is one of the primary mechanisms for tectonic fault slip, because fluids lubricate the fault and fluid pressure reduces the effective normal stress that holds the fault in place. However, current models of earthquake nucleation, based on rate- and state- friction laws, imply that stable sliding is favoured by the increase of pore fluid pressure. Despite this controversy, curr...

A pair of significant earthquakes occurred on conjugate faults in the western Imperial Valley involving the through-going Superstition Hills fault and the Elmore Ranch cross fault. The first event was located on the Elmore Ranch fault, Ms = 6.2, and the larger event on the Superstition Hills fault, Ms = 6.6. The latter event is seen as a doublet teleseismically with the amplitudes in the ratio ...

The Ricardo Group is a 1,700-m-thick sequence of Miocene volcanic rocks and continental sedimentary rocks deposited between ~19 and 7 Ma in the El Paso basin, near the junction of the Garlock fault and the Sierra Nevada frontal fault in southern California. The combination of stratigraphic and structural data from the Ricardo Group with chronologic and rotational histories derived from magnetos...