Geology and Geological Engineering

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

Dr. Timothy Masterlark

Ph.D. (2000), University of Wisconsin
Professor and Mickelson Professorship
South Dakota School of Mines
Rapid City, SD 57701
email masterlark@sdsmt.edu

h-index:18 , i10-index: 20

keywords: Earthquake, Earthquake Triggering, Finite Element Model, FEM, Fracture Propagation, Geodesy, Geomathematics, Geophysics, Geothermal, GPS, Gravity, Hydrofracking, Hydrogeology, Induced Seismicity, InSAR, Inverse Methods, Modeling, Optimization and Uncertainty, Poroelastic Mechanics, Thermoelastic Mechanics, Time Series, Transient Deformation, Tsunami, Viscoelastic Deformation and Creep, Volcano

Research synopsis

Fluid-solid coupling drives the dynamic systems of volcanoes, earthquakes, and tsunamis. Magma propagates in dikes within active volcanoes. Megathrust earthquakes shift the seafloor, which excites tsunami waves in the overlying ocean. 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 principles of fluid-solid coupling are useful for understanding energy production. Hydrofracking propagates fluid-filled fractures that unlock hydrocarbons from unconventional reservoirs. The waste fluids are disposed of via deep injection, which perturbs the ambient stress and fluid pressure and triggers seismsicity. These principles are naturally extended to studies of geothermal systems.

My research team specializes in using Abaqus-based Finite Element Models (FEMs) to simulate these systems. We are pioneering methods to embed FEMs in nonlinear inverse analyses of geophysical information to quantify deformation sources at depth. Example targets include:

  • NSF Geophysics (2013-2017)
    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 (2012-2017)
    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