Two monuments from an 1855 cadastral survey that span the San Andreas fault in the Carrizo Plain have been right-laterally displaced 11.0 --2.5 m by the 1857 Fort Tejon earthquake and associated seismicity and afterslip. This measurement confirms that at least 9.5 --0.5 m of slip occurred along the main fault trace, as suggested by measurements of offset channels near Wallace Creek. The slip va...

There are several lines of evidence that suggest that thermal pressurization (TP) of pore fluid within a low-permeability fault core may play the key role in the development of earthquake slip. To elucidate effects of TP on spontaneous fault slip, I consider solutions for a steadily propagating slip pulse on a fault with a constant sliding friction, the level of which may reflect other thermall...

We estimate the critical slip-weakening distance on earthquake faults by using a new approach, which is independent of the estimate of fracture energy or radiated seismic energy. The approach is to find a physically based relation between the breakdown time of shear stress Tb, the time of peak slip-velocity Tpv, and the slip-weakening distance Dc, from the time histories of shear stress, slip, ...

Fabric analysis of the upper 1300m of the Dome C ice core reveals a slight clustering tendency of c axes towards vertical, which gradually enhances with depth from an initially isotropic orientational distribution of c axes at the free surface. Such a strain induced anisotropy is compatible with the expected macroscale stress state in a dome, viz. dominated by vertical compression. Yet, when on...

In continuum mechanics inelastic deformation is attributed to the aggregate effect of irreversible gliding of atoms along well defined planes whose number and orientation depends on the crystallographic structure of the material. Such a gliding plane and its pertaining gliding direction are termed “slip system”. It is activated by mechanical stresses expressed in terms of the resolved shear str...

Intermittent sliding (stick-slip motion) between solids is commonplace (e.g., squeaking hinges), even in the presence of lubricants, and is believed to occur by shear-induced fluidization of the lubricant film (slip), followed by its resolidification (stick). Using a surface force balance, we measure how the thickness of molecularly thin, model lubricant films (octamethylcyclotetrasiloxane) var...

Geodetic studies have produced different interpretations of the relative vertical thickening versus escape tectonics occurring within the Los Angeles basin based on calculated horizontal strain rates ranging from 56 10 /yr contraction at N36 E to 85 10 /yr north–south contraction and 60 10 /yr east–west extension. Three-dimensional forward mechanical models of faults in the Los Angeles basin ar...

An annular shear cell has been used to investigate a number of factors known to influence stick-slip motion in an assembly of near monosized, spherical glass beads. In this paper, both the sample shear stress and volumetric strain were recorded, allowing new insights into the possible mechanics of stick-slip motion in a granular body. Rather than the commonly presented mechanism of sample dilat...

The 2011 Tohoku earthquake (Mw 9.0) produced a very large slip on the shallow part of a megathrust fault that resulted in destructive tsunamis. Although multiple causes of such large slip at shallow depths are to be expected, the frictional property of sediments around the fault, particularly at coseismic slip velocities, may significantly contribute to large slip along such faults. We have thu...

Recent observations suggesting the influence of creep on earthquakes nucleation and arrest are strong incentives to investigate the physical mechanisms controlling how active faults slip. We focus here on deriving generic characteristics of shallow creep along the Haiyuan fault, a major strike-slip fault in China, by investigating the relationship between fault slip and geometry. We use optical...