27. Investigations of Fluid and Heat Transport in Fractured Hydrothermal Systems

Results from recent investigations of active hydrothermal systems highlight the interrelationships of stress, seismic activity, mineralogy, temperature and fluid chemistry in creating and maintaining fracture permeability. Characterizing and quantifying these relationships and the resulting effects on local and regional fluid and heat transport is a key objective of USGS research.

Ongoing USGS geothermal studies conducted in collaboration with the Department of Energy (DOE) include acquisition and analysis of a wide array of geological, geophysical, and geochemical data bearing on the nature and extent of fault-hosted hydrothermal systems in diverse tectonic environments. In addition, a renewed focus on expanding the conventional geothermal energy resource base through the enhancement of existing fracture permeability and the creation of new geothermal reservoirs poses a significant challenge for USGS investigators and their partners to develop new tools for characterizing and modifying permeability in situ. This work builds on ongoing geothermal resource assessment studies and related investigations of the mechanical, chemical, thermal and hydraulic properties of active fault zones for earthquake hazards, volcano hazards, and hydrologic studies.

A postdoctoral research scientist is sought to study the formation and evolution of fault and fracture permeability in support of USGS investigations into the factors controlling the nature and extent of hydrothermal systems in the western United States. Projects associated with this work include geothermal energy resource assessments, borehole and surface-based studies of active fault zones, and characterization of magmatic-hydrothermal processes. Data sets collected by the USGS and collaborating researchers at other institutions include observations of heat flow, potential fields, in situ stress, subsurface fracture orientations and properties, water and gas geochemistry, physical properties, surficial geology, and hydrothermal alteration.

Depending on the background and qualifications of the candidate, he/she will conduct research in one or more of the following areas:

• Integrated geological, geochemical and geophysical investigations of individual hydrothermal systems,
• Coupled heat, fluid and reactive transport models for the formation and evolution of active fault-hosted hydrothermal systems,
• Analysis of downhole measurements of physical properties, fracture orientation, stress, fluid pressure, temperature and fluid chemistry to identify the factors controlling the magnitude, distribution and longevity of fracture permeability, or
• Regional thermal, geohydrologic, potential field and tectonic studies to evaluate the favorability of the targeted areas for geothermal reservoir enhancement and the use of these results to improve geothermal resource assessment methodology.

Proposed Duty Station: Menlo Park, CA

Areas of Ph.D.: Geophysics, geology, hydrogeology, volcanology, physics, fluid mechanics, mineralogy

Qualifications: Applicants must meet one of the following qualifications: Research Geologist, Research Geophysicist, Research Hydrologist, Research Chemist

(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.)

Research Advisor(s): Colin Williams, (650) 329-4881, colin@usgs.gov; Stephen Hickman, (650) 329-4807, hickman@usgs.gov; Steven Ingebritsen, (650) 329-4422, seingebr@usgs.gov

Human Resources Office contact: Candace Azevedo, (916) 278-9393, caazevedo@usgs.gov

Summary of Opportunities