The University of Texas Institute for Geophysics conducts 2D and 3D kinematic modeling of complex geologic systems using leading industry software.
Subduction zones are settings where two plates converge, causing one to subduct beneath the other as it passes into the mantle. The collision process generates the world’s largest and most destructive earthquakes and tsunamis along with complex deformational structures from folding, thrust faulting, and internal shortening within the accretionary wedge that piles up in the subduction zone. By using kinematic models to undo this process and restore the strata to their original depositional geometry, we can test the interpretations of these structures to better understand the collision process and the implications for seismicity and forearc development (Figure 1).
A graduate student-led study is currently underway to examine seamount collisions in the Hikurangi Subduction Zone along the North Island of New Zealand. Here, the subducting plate is the Hikurangi Plateau, which has a large number of seamounts protruding well above the trench sediments.
Subducting seamounts have been implicated in causing slow slip earthquakes (earthquakes that last for weeks rather than the typical duration of seconds for normal earthquakes), which are common in this setting, as they are pulled into the margin. Previous numerical modeling has predicted fault patterns associated with seamount subduction (Figure 2), but the seamount collision process and its link to fault slip behavior are not well known. UTIG is conducting 3D kinematic modeling of a seamount collision seen with a recently acquired 3D seismic reflection data set to unravel collision processes and advance our understanding of how these collisions can impact fault slip behavior.
UTIG kinematic modeling is supported by Petroleum Experts, who generously gifted The University of Texas at Austin use of their MOVE software, valued at $2.7 million, for use in this research.
Senior Research Scientist
University of Texas Institute for Geophysics