20. Automated detection of anomalous hydrothermal and volcanic activity from space

Thermal remote sensing is a tool in monitoring volcanic eruptions with growing importance: satellite data have been used to detect, track, and quantify eruption clouds and lava effusion (for example, Wright and others, 2004; Pieri and Abrams, 2004; Rose and others, 2000). Volcanoes can also exhibit far less dramatic thermal anomalies prior to eruption. Rising magma (and a host of other processes) can disturb hydrothermal and groundwater systems. Improved monitoring of these broader, lower-temperature systems has a broad spectrum of uses, including longer-term forecasts of volcanic activity and detecting the effects of variations in climate. By using satellite, airborne and ground-based sensors we can extend the current state-of-the art to detect these subtle thermal changes that may be precursors to eruptions. To do so requires development of new methodologies to compare and fuse data from multiple sensors into a geo-referenced framework, and ultimately to model the processes responsible for variations in heat flow.

We seek a postdoctoral fellow to help (a) extract information on changes in active hydro-thermal systems from space-borne sensors, with emphasis on thermal infrared data; (b) enhance existing software tools to automate the detection of changes; and (c) develop methods to disseminate the results electronically in a GIS-friendly format. We propose that the work initially focus on the largest natural thermal area on the planet, Yellowstone National Park. The park sits astride a large crustal magma chamber, and exhibits frequent temporal thermal changes (Lowenstern and others, 2006). Thus, it arguably provides the best “ground truth” on Earth for testing algorithms that can isolate and analyze thermal anomalies on non-erupting volcanoes.

A wide variety of thermal infrared data is available for research and analysis under this proposed project. Yellowstone National Park has sponsored annual high-resolution geo-referenced thermal infrared surveys (conducted by University collaborators) over the past two years. Comparisons of these annual surveys would be made with more frequent (but lower spatial resolution) thermal infrared data from satellite sensors such as ASTER, LANDSAT, MODIS, and AVHRR. Visible and near-infrared spectra from these same sensors may help understand the nature of the detected changes. High spatial resolution field campaigns utilizing thermal imaging (that is, FLIR) and/or point-source radiometers are possible as appropriate. Additional datasets from thermal, gas and geophysical monitoring equipment operated by the Yellowstone Volcano Observatory are available to help place the remotely sensed data into context.

The hypothesis to be tested is that changes in output from the hydrothermal system can be retrieved by systematic comparison of satellite data collected over time. The results of these analyses will be compared to data from existing and planned low-altitude airborne thermal infrared missions, and campaign-style ground-based studies. Automation techniques will be leveraged from those developed by the USGS for the Global Land Ice Measurement from Space (GLIMS) project (Rau and others, 2006) in order to produce precisely geo-referenced data that allow comparisons of like features. The background diurnal, weather-related, and seasonal ground temperature changes need to be modeled and removed and the data corrected for atmospheric attenuation. Although precise measurement of heat flow from satellite methods is difficult, it is likely that relative changes will be clearly identified. The project would provide Yellowstone National Park with an improved systematic protocol to address long-term changes to its hydrothermal system related to climatic, anthropogenic or volcanic activity. Maps of heat discharge and associated change can be used to model subsurface thermal sources.

References

Lowenstern, J.B., Smith, R.B., and Hill, D.P., 2006, Phil. Trans. Royal Soc. A, v. 364, p. 2055–2072.

Pieri, D., and Adams, M., 2004, J. Volc. Geothermal Res., v. 135, p. 13–28.

Rau, F., Kargel, J.S., and Raup, B.H., 2006, Earth Observer, v. 18, p. 9–11.

Rose, W.I., Bluth, G.J.S., and Ernst, G.G.J., 2000, Phil. Trans. Royal Soc. A, v. 358, p. 1585–1606.

Wright, R., and others, 2004, J. Volc. Geothermal Res., v. 135, p. 29–49.

Proposed Duty Station: Flagstaff, AZ; Anchorage, AK; Menlo Park, CA

Areas of Ph.D.: Volcanology, remote sensing, and related fields

Qualifications: Applicants must meet one of the following qualifications: 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.)

Research Advisor(s): Laszlo Keszthelyi, (928) 556-7002, laz@usgs.gov; David Schneider, (907) 786-7037, djschneider@usgs.gov; Jacob Lowenstern, (650) 329-5238, jlwnstrn@usgs.gov; Cheryl Jaworowski (Yellowstone National Park), (307) 344-2208, cheryl_jaworowski@nps.gov

Human Resources Office contact: Erica Settlemyer, (916) 278-9383, esettlemyer@usgs.gov

Summary of Opportunities