Normal fault earthquakes or graviquakes

Normal fault earthquakes or graviquakes

Earthquakes are dissipation of energy throughout elastic waves. Canonically is the elastic energy accumulated during the interseismic period. However, in crustal extensional settings, gravity is the main energy source for hangingwall fault collapsing. Gravitational potential is about 100 times larger than the observed magnitude, far more than enough to explain the earthquake. Therefore, normal ...

Fault geometry and earthquakes in continental interiors

Although large earthquakes in continental interiors are much less frequent than those along plate boundaries, they have been responsible for a disproportionate amount of destruction. I present a testable model for strain accumulation and seismicity in the upper crust of continental interiors. Intersecting faults provide a focus for strain build-up, resulting in local pockets of high strain accu...

Resolving Fault Plane Ambiguity for Small Earthquakes

Experimental investigation of strong groundmotion due to thrust fault earthquakes

Thrust fault earthquakes are studied in a laboratory earthquake setup previously used to investigate analog strike-slip seismic events. Dynamic mode II ruptures are generated along preexisting faults in an analog material, Homalite H-100, and their interaction with the free surface is studied for both sub-Rayleigh and supershear rupture speeds. High-speed digital photography and laser velocimet...

Repeating deep earthquakes: evidence for fault reactivation at great depth.

We have identified three groups of deep earthquakes showing nearly identical waveforms in the Tonga slab. Relocation with a cross-correlation method shows that each cluster is composed of 10 to 30 earthquakes along a plane 10 to 30 kilometers in length. Some of the earthquakes are colocated, demonstrating repeated rupture of the same fault, and one pair of events shows identical rupture complex...