We estimated horizontal velocities at 25 sites first surveyed in a 1901–1903 British Ordnance Survey triangulation and then resurveyed with GPS in 1994–1995 to identify Trinidad’s principal active on-land faults, quantify fault-slip-rates, and test for elastic locking. Our best-fit single-fault elastic dislocation model put 12 3 mm/yr of dextral strike-slip on the Central Range Fault (1–2 km lo...

The Pasadena earthquake (ML ~4.9) occurred on 3 December 1988, at a depth of 16 km. The hypocenters of the earthquake and its aftershocks define a eastnortheast striking, steeply northwest-dipping surface that projects up to the active surficial trace of the Raymond fault. One of the nodal planes of the focal mechanism of the earthquake parallels the Raymond fault with left-lateral strikeslip m...

We study how the fault dip and slip rake angles affect near-source ground velocities and displacements as faulting transitions from strike-slip motion on a vertical fault to thrust motion on a shallow-dipping fault. Ground motions are computed for five fault geometries with different combinations of fault dip and rake angles and common values for the fault area and the average slip. The nature ...

The ground motion and damage caused by the 2015 Gorkha, Nepal earthquake can be characterized by their widespread distributions to the east. Evidence from strong ground motions, regional acceleration duration, and teleseismic waveforms indicate that rupture directivity contributed significantly to these distributions. This phenomenon has been thought to occur only if a strike-slip or dip-slip r...

The Cantabrian Fault is a long-lived crustal fault, 320 km long on land and extending more than 150 km seawards within the Bay of Biscay, which separates different geodynamic domains. Due to its sub-vertical dip and late strike slip movement is poorly evidenced in the shelf and it has been traditionally mapped following the strike of the deepest submarine canyon in the north Atlantic (~4.600 m ...

We perform a detailed parameter-space study on properties of yielding zones generated by 2-D in-plane dynamic ruptures on a planar fault with different friction laws and parameters, different initial stress conditions, different rock cohesion values, and different contrasts of elasticity and mass density across the fault. The focus is on cases corresponding to large strike-slip faults having hi...

This paper is concerned with some aspects of nonuniform stressing above a deep creeping portion of a fault zone prior to a large crust-breaking earthquake. The model that we use involves a slipping crack, representing the deeper, more stably sliding portions of the fault zone, which penetrates upward from depth and is blocked in the lower region of the seismogenic zone. When conditions are unif...

We have determined a source rupture model for the 1992 Landers earthquake (Mw 7.2) compatible with multiple data sets, spanning a frequency range from zero to 0.5 Hz. Geodetic survey displacements, near-field and regional strong motions, broadband teleseismic waveforms, and surface offset measurements have been used explicitly to constrain both the spatial and temporal slip variations along the...

[1] We report on laboratory experiments which investigate interactions between aseismic slip, stress changes, and seismicity on a critically stressed fault during the nucleation of stick-slip instability. We monitor quasi-static and dynamic changes in local shear stress and fault slip with arrays of gages deployed along a simulated strike-slip fault (2m long and 0.4m deep) in a saw cut sample o...