We investigated the shear strain field ahead of a supershear rupture. The strain array data along the sliding fault surfaces were obtained during the large-scale biaxial friction experiments at the National Research Institute for Earth Science and Disaster Resilience. These friction experiments were done using a pair of meter-scale metagabbro rock specimens whose simulated fault area was 1.5 m ...

Normal mode solutions for • spherical earth model are superposed to obtain realistic synthetic surface waves for various force systems. The calculation of excitation functions is greatly facilitated by the variational technique. The effects of attenuation anal instrument response are included in the synthesis. The synthesized seismograms are compared with the actual seismograms for wave form, a...

In this study, an alternative method for conducting probabilistic fault displacement hazard analysis is developed based on stochastic source modeling and analytical formulae evaluating the elastic dislocation due to earthquake rupture. It characterizes uncertainty of fault-rupture occurrence in terms its position, geometry, slip distribution adopts so-called Okada equations calculation ground s...

There is strong evidence that the 11 March 2011 Tohoku earthquake rupture reached the seafloor. This is surprising because the shallow portion of the plate interface in subduction zones is thought to be frictionally stable, leading to the widely held view that coseismic rupture would stop several tens of kilometers downdip of the seafloor. Various explanations have been proposed to reconcile th...

Theoretical studies have shown that the issue of rupture modes has important implications for fault constitutive laws, stress conditions on faults, energy partition and heat generation during earthquakes, scaling laws, and spatiotemporal complexity of fault slip. Early theoretical models treated earthquakes as crack-like ruptures, but seismic inversions indicate that earthquake ruptures may pro...

The 17 December 2016 Solomon Islands earthquake (Mw 7.9) initiated ~103 km deep in the subducting Solomon Sea slab near the junction of the Solomon Islands and New Britain trenches. Most aftershocks are located near the Solomon Islands plate boundary megathrust west of Bougainville, where previous large interplate thrust faulting earthquakes occurred in 1995 (Mw 7.7) and 1971 (Mw 8.0). Teleseis...

We study dynamic rupture propagation on flat faults using 2D plane strain models featuring strongly rate-weakening fault friction (in a rate-and-state framework) and off-fault Drucker–Prager viscoplasticity. Plastic deformation bounds stresses near the rupture front and limits slip velocities to ∼10 m=s, a bound expected to be independent of earthquake magnitude. As originally shown for rupture...

[1] Building upon previous laboratory earthquake experiments of dynamic shear rupture growth taking place along faults with simple kinks, new and complex fault geometries involving cohesively held fault branches are studied. Asymmetric impact at the specimen boundaries controls the incoming shear ruptures, which are manipulated to propagate at either sub-Rayleigh or supershear velocities. High-...

Abstract On 8 August 2020, northwest North Carolina experienced an Mw 5.1 earthquake that caused damage to buildings and roads in the city of Sparta. A regional centroid moment tensor solution shows was result slip on a reverse fault with minor strike-slip component. Interferometric Synthetic Aperture Radar (InSAR) data, from Japan Aerospace Exploration Agency’s Advanced Land Observing Satellit...

Repeated earthquakes and explosions recorded at the San Andreas fault (SAF) near Parkfield before and after the 2004 M6 Parkfield earthquake show large seismic velocity variations within an approximately 200m-wide zone along the fault to depths of approximately 6 km. The seismic arrays were co-sited in the two experiments and located in the middle of a high-slip part of the surface rupture. Wav...