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18-2. Earthquake ground motions and seismic hazard in the Pacific Northwest

 

Closing Date: January 6, 2020

This Research Opportunity will be filled depending on the availability of funds. All application materials must be submitted through USAJobs by 11:59 pm, US Eastern Standard Time, on the closing date.

CLOSED

Earthquakes in the Pacific Northwest are a significant hazard to major population centers in Seattle, Washington; Portland, Oregon; and Vancouver, British Columbia. The Cascadia subduction zone is capable of generating three types of earthquakes: shallow, crustal earthquakes in response to regional deformation (e.g., the 900 A.D. Seattle fault and 1872 North Cascades earthquakes); deep earthquakes in the subducting Juan de Fuca slab (e.g., earthquakes in 1949, 1965, and 2001); and ~M8-9 earthquakes on the megathrust fault offshore (e.g., 1700 Cascadia earthquake). All of these earthquake scenarios will produce strong ground shaking that can damage the built and natural environments, as well as cause loss of life.

We seek a candidate to conduct research on earthquake ground motions in the Pacific Northwest, for the purpose of improving seismic hazard estimates and increasing public safety. Ground motions depend upon the characteristics of the earthquake source, the seismic velocity structure that the seismic waves traverse, and the near-surface site conditions; therefore, scientific research relevant to any of these topics is encouraged. A wide range of research questions may be explored, including but not limited to:

  • 3-D Earthquake Simulations (Kinematic or Dynamic): What is the expected ground shaking during megathrust, intraslab, or crustal earthquakes in the Pacific Northwest? How do characteristics of the earthquake source and rupture process impact the resulting ground motions? What physical conditions dictate the extent of earthquake rupture? How can observations of global earthquakes be used to inform models for earthquakes in the Pacific Northwest?

  • Amplification of Ground Motions in Sedimentary Basins: How do sedimentary basins in the Pacific Northwest amplify earthquake ground shaking? How is ground motion amplification impacted by additional complexities, such as rupture directivity, traversing multiple sedimentary basins, or non-linearity? 

  • Analyses of Observed Local Earthquakes:  How does the character (e.g., stress drop, rupture directivity) of local seismicity vary with depth and tectonic setting? How does propagation through the crust and upper mantle affect recorded ground motions? How are ground motions from local earthquakes amplified by shallow soils, such as fill and alluvium, at individual sites throughout the Pacific Northwest?

  • Constraining 3-D Seismic Velocity Structure: What is the seismic velocity and attenuation structure of the Pacific Northwest as informed from full waveform tomography? How can converted seismic phases be used to constrain sharp impedance contrasts that may impact earthquake ground shaking?

The Mendenhall Fellow will be stationed at the Earthquake Science Center’s field office in Seattle, Washington, on the University of Washington campus. Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas.

Proposed Duty Station: Seattle, WA

Areas of PhD: Geophysics, seismology, geology, earthquake engineering 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, Research Geologist

(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