From a hazards standpoint, the shallowest earthquake slip may be the most important part of the rupture process to understand because it is this slip that directly impacts the built environment, including both above-ground construction and buried infrastructure such as pipelines. Yet shallow slip is actually quite poorly understood because it can only be observed by measurements made very near to faults. (Observations from farther away instead record the history of deeper slip.) The collection of near-fault measurements of fault displacements and near-field deformation following significant earthquakes is small. But due to the rapid response of researchers to the 2019 M7.1 and M6.4 Ridgecrest earthquake sequence and 2014 M6.0 South Napa earthquake, we at last have modern, dense geodetic datasets of near-fault deformation for multiple earthquakes in addition to good seismic observations.
For the first time ever, we have modern optical and radar satellite imagery, airborne imagery, and ground based laser scanning available for multiple earthquakes. Furthermore, in addition to good regional seismic network coverage and temporary seismic and geodetic deployments following the Napa and Ridgecrest earthquakes, there are dense, cross-fault seismic arrays (including nodal deployments) for complementary damage zone studies. Thus this is the first opportunity the earthquake science community has had to constrain the physics of shallow rupture and begin building detailed hazard assessments for the risk posed by shallow fault rupture, distributed off-fault deformation, and afterslip to humans and infrastructure.
As datasets of this type have never been collected before, there are numerous opportunities for a post-doctoral fellow possessing originality, innovation, and independent research leadership skills to better understand the physics of shallow deformation and hazards due to shallow fault rupture. Potential avenues of research include, but are not limited to, developing theoretical or geomechanical models of shallow rupture mechanics and validating them against observed near-field displacement observations, developing new data processing or data mining techniques, identifying the rheology of shallow faults through models and/or laboratory experiments, developing kinematic or dynamic rupture models that embrace the high spatial resolution of these new geophysical data sets to image fault slip in detail, modeling the structure and mechanics of shallow fault systems, designing new computational methods to accomplish any of the preceding, conducting analog lab experiments of shallow faulting, or leading field experiments to identify time-dependent changes in fault structure and shallow post-seismic deformation. There is also opportunity to explore how geological evidence of surface slip relates to sub-surface slip, a relationship that is crucial to both the Uniform California Earthquake Rupture Forecast (UCERF) and the National Seismic Hazard Model (NSHM)
Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas.
Proposed Duty Station: Moffett Field, CA, or Pasadena, CA
Areas of PhD: Geophysics, seismology, or related fields (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered).
Qualifications: Applicants must meet the qualifications for: Research Geophysicist
(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)
Human Resources Office Contact: Audrey Tsujita, 916-278-9395, atsujita@usgs.gov
