Geophysics Research

A large part of my work in geophysics was as a developer and researcher for the Virtual Quake and Tsunami Squares++ projects.

See more of my results at my ResearchGate profile.

Simulation of the 2009 Tohoku Tsunami

On March 11th 2009, a magnitude 9.0 megathrust earthquake occurred off the east coast of northern Honshu, Japan. The resulting sea floor uplift caused a massive displacement of water that resulted in one of the most damaging tsunamis on record. As part of the development and validation of Tsunami Squares++, the sea floor uplift was used as initial conditions for a wave simulation.

TohokuFar_x1_Satake13dip10_output_000-4800_grid.mp4

The first 40 minutes after the earthquake. Color scale is saturated

TohokuSmall_x2_contSatake13X1_output_800-4800_absorb_grid.mp4

Higher resolution simulation of the run-up of water onto land

Fractal Geometry in Faults

Virtual Quake uses 3D models of known faults to simulate earthquakes. However, these models are often smooth, planar surfaces, lacking the fractal-like complexity of real rock fractures. I investigated the effects of included these fractal deviations in the Virtual Quake Fault models.

Top: a totally flat modeled fault

Bottom: introducing fractal deviations from the straight line

Distribution of magnitudes of earthquakes that occur on the simulated faults. The single purple dot on the right represents the single large repeating earthquake that occurs on the flat fault, while the other data corresponds to the more natural wide range of magnitudes emergent from fractal faults.

Aftershock models as simulator validation

The fault models used by Virtual Quake and similar simulators only include the largest known mapped faults. However, we know that the epicenters of many earthquakes occur on smaller faults located near the larger ones. Using simulator outputs combined with spatial aftershock distributions, I created maps for the spatial validation of four simulators.

The absolute values of the scales below are non-physical. Instead, the values are compared within the same map to determine if each simulator was anticipating higher seismic rates in the correct locations.

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