[1] We investigate the rupture process of the 1999 Chi-Chi, Taiwan, earthquake using extensive near-source observations, including three-component velocity waveforms at 36 strong motion stations and 119 GPS measurements. A three-plane fault geometry derived from our previous inversion using only static data [Ji et al., 2001] is applied. The slip amplitude, rake angle, rupture initiation time, a...

During the great 3 May 1887 Sonoran earthquake (surface rupture end-to-end length: 101.8 km; MW = 7.5±0.3), an array of three north-south striking Basin and Range Province faults (from north to south Pitáycachi, Teras, and Otates) snapped along the western margin of the Sierra Madre Occidental plateau. My detailed fi eld survey of the Teras fault and the 1887 earthquake rupture zone along this ...

In constructing moment-balanced fault rupture models for the SF Bay region, WG99 needed to account for all the moment released by earthquakes in the region. These include earthquakes on characterized rupture sources, earthquakes on other rupture sources (background), and their aftershocks. Some of the aftershocks will be large, with magnitudes sometimes exceeding 6.7. WG99 assumed that an after...

[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...

[1] The effect of off-fault damage on the speed of ruptures propagating on faults in photoelastic Homalite plates was measured using high-speed digital photography. The offfault damage was composed of a network of fractures introduced by thermally shocking the Homalite in liquid nitrogen. The mode II rupture speed measured in damaged Homalite was significantly lower than the limiting Rayleigh s...

We have conducted a paleoseismic investigation of serial fault rupture at one site along the 110-km rupture of the North Anatolian fault that produced the Mw 7.4 earthquake of 17 August 1999. The benefit of using a recent rupture to compare serial ruptures lies in the fact that the location, magnitude, and slip vector of the most recent event are all very well documented. We wished to determine...

The 1999 M 7.1 Hector Mine earthquake ruptured a complex fault system with a branched structure in the north. This fault geometry and slip pattern presents a puzzle, because the northwest branch of this system should be in the stress shadow of the north branch, upon which nucleation likely took place. Through 3D dynamic models of this event, we show that the ability of rupture to propagate to t...

Abstract We have developed a forward modeling technique to retrieve rupture characteristics of small earthquakes (3 < M < 5), including rupture propagation direction, fault dimension, and rupture speed. The technique is based on an empirical Green’s function (EGF) approach, where we use data from collocated smaller events as Green’s functions to study the bigger events. We tend to choose smalle...

Observations demonstrate that faults are fractal surfaces with deviations from planarity at all scales. We study dynamic rupture propagation on self-similar faults having root mean square (rms) height fluctuations of order 10 3 to 10 2 times the profile length. Our 2D plane strain models feature strongly rate-weakening fault friction and off-fault Drucker–Prager viscoplasticity. The latter boun...

A rupture model with varying rupture front expansion velocity for the March 11, 2011, Tohoku-Oki earthquake was obtained by the joint inversion of high-rate Global Positioning System (GPS) data and ocean bottom GPS/acoustic (OB-GPS) data. The inverted rupture velocity with a complex distribution gradually increases near the hypocenter and shows rapid rupture expansion at the shallowest part of ...