Geology and Geological Engineering

Dr. Tim Masterlark
Geodynamics: Exploring Earth with Numerical Models
Research Teaching People News & Links Publications CV

Dr. Tim Masterlark

Ph.D. (2000), University of Wisconsin
Professor and Mickelson Professorship
South Dakota School of Mines
Rapid City, SD 57701
email masterlark@sdsmt.edu
phone +1 605-394-2461
fax +1 605-394-6703

Research synopsis

As residents of a dynamic planet, we face many challenges from volcanic eruptions, earthquakes, and tsunamis. From a physical standpoint, fluid-solid coupling drives these dynamic systems. Fluid magma propagates in dikes through solid rock to remain in storage at depth or erupt from a volcano. The coseismic shift of the solid seafloor excites the overlying ocean, resulting in tsunami waves. These fluid waves, in turn, interact with the solid coastal areas with devastating consequences. Large earthquakes transfer stress to the region surrounding the rupture. Diffusive flow of pore fluids in the crust and viscous flow of the mantle relax these stresses, producing delayed aftershocks.

The processes of fluid-solid coupling are are extended to energy production. Hydrofracking propagates fluid-filled fractures that unlock hydrocarbons from unconventional reservoirs. The waste ("fracking") fluids are disposed of via deep injection, which perturbs the ambient stress and fluid pressure and triggers seismsicity. These principles of propagating fluid-filled fractures are useful for improving the efficiency of geothermal systems.

My Geodynamics Research Team specializes in using Abaqus-based Finite Element Models (FEMs) to simulate fluid-solid coupling that drives deformation systems of earthquakes, volcanoes, fluid-filled fracture propagation, and induced seismicity. We are pioneering methods to embed FEMs in nonlinear inverse analyses that use observations of Earth's surface deformation and seismicity to quantify inaccessible deformation sources at depth. The Geodynamics Laboratory is equipped with Heavy Workstations (multi-core CPUs, TFLOP GPU acceleration, Big RAM, and Solid-state drives) that are specifically designed for FEM-based analyses. Example targets include:

  • NSF Geophysics (2013-2016)
    FEM-based inverse methods to estimate nonlinear geometric source parameters of volcano deformation from geodetic data. Study sites are Okmok volcano, Alaska, and Tunguraha, Ecuador.

  • NASA ROSES ESI (2012-2016)
    Near-field postseismic poroelastic deformation, InSAR observations, and modeling. Multiple study sites. Collaborative research with NASA JPL.

  • JAXA 4th ALOS Research Announcement for ALOS-2 (2013-2017)
    Interferometric analysis of JERS-1, ALOS, and ALOS-2 SAR data for Okmok Volcano to constrain dynamic models of magmatic processes.

  • JAXA 6th ALOS Research Announcement for ALOS-2 (2016-2018)
    Validating interpretations of ALOS-2 data for the 2015 M8.3 Chile earthquake: Calibration of co-seismic and post-seismic deformation and assessment of transient seismic hazard .
FEMs of mega-earthquakes: Viscoelastic relaxation translates to postseismic deformation and stress.

FEM of Tungurahua Volcano: This model simulates deformation caused by a pressurized dike embedded in the complex domain of an active volcano.

Hydrofracking simulations: Abaqus XFEM simulates the propagation of a fluid-filled fracture in a 2D domain.
contact: Dept. of Geology and Geological Engineering, 501 E. Saint Joseph St., SDSMT, Rapid City, SD 57701
phone: (605)394-2461 / fax: (605)394-6703 / email: masterlark@sdsmt.edu