********************************************************************* From: Shaul Hurwitz <shaulh@xxxxxxxx> ********************************************************************* Dear colleagues, The next cycle of the USGS Mendenhall Postdoctoral Research Fellowship Program provides an opportunity to study groundwater dynamics and its effects on volcanism at Mount St. Helens http://geology.usgs.gov/postdoc/2010/opps/opp45.html. Candidate must have completed their PhD between November 12, 2003 and March 31, 2010. Non U.S. citizens can apply, but they face a stiffer (but not insurmountable) challenge in submitting a successful application. APPLICATION DEADLINE IS NOVEMBER 12, 2008. _________________________________________________________________________________________ Groundwater dynamics at an active stratovolcano Groundwater and reactive magmatic volatiles play a pivotal role in various volcanic processes that pose significant hazards, from edifice collapse to explosive eruption. Yet, there is little direct knowledge of the hydrogeology of active volcanoes. Basic hydrogeological and geochemical parameters, such as water-table elevation, recharge and flow rates, residence times, volatile fluxes, and thermal parameters, critical for constraining hydrogeological models remain unknown. The primary information we have regarding volcano hydrogeology comes from analysis of a single deep well at Kilauea Volcano (Hurwitz and others, 2002), from numerical modeling of groundwater and heat flow within a hypothetical stratovolcano (Hurwitz and others, 2003), from analyses of volcano seismicity hypothesized to be induced by seasonal groundwater recharge (for example, Christiansen and others, 2005), and from inferences obtained from aeromagnetic surveys (Finn and others, 2001). Comprehensive analysis of volcano hydrogeology and its effects on volcanic processes is lacking, chiefly because few drill holes exist on or near active volcanoes; hence, less direct methods must be explored. Springs can provide information on groundwater dynamics and volatile fluxes in regions lacking wells (Manga, 2001), and may provide essential data on volcano hydrogeology. At Mount St. Helens (MSH), numerous cold and hot springs surround the volcano and afford a superb opportunity to study 3D interactions of hydrogeological and volcanic processes. Ongoing studies at MSH include analyses of these springs to characterize fluxes of magmatic volatiles and other components into groundwater to elucidate magmatic degassing. Additional studies are needed to characterize recharge rates, flow paths, and physical properties such as volcano permeability and phase distribution. These factors greatly influence magmatic heat transport, rock alteration, eruption explosivity, and the potential for volcanic mass-wasting. Critical both to volcano-hazards and mineral-resource programs is an increased understanding of both volatile sources and the mechanisms for "scrubbing" (condensing and dissolving) volatiles into groundwater to produce hydrothermal fluids and rock alteration. We seek a postdoctoral fellow to investigate the hydrogeology of Mount St. Helens using inferential methods and modeling, and to relate groundwater dynamics to volcanic processes. In particular, we seek a scientist who can use innovative methods to constrain and couple groundwater dynamics with models that might address, for example, the fate of meltwater from the crater glacier; transport of magmatic gas and heat and its influence on magma ascent and explosivity; or the potential for large-scale mass wasting of the crater floor. We especially encourage innovative uses of isotopic analyses (noble gases, CFCs, stable isotopes), geophysical surveys, and mathematical modeling relevant to an active volcano. The Mendenhall Fellow will have the opportunity to work collaboratively with U.S. Geological Survey (USGS) scientists actively engaged in research on volcano hydrology and volcano hazards, and will have access to USGS chemical and isotope labs. Research under this Opportunity would be a first step toward addressing groundwater dynamics and associated coupling with volcanic processes at this particular volcano, and has the potential to develop fundamental and transferable insights regarding active stratovolcanoes in general. Questions regarding the specific opportunity described above can be directed to: Steve Ingebritsen - seingebr@xxxxxxxx Jon Major - jjmajor@xxxxxxxx Bill Evans - wcevans@xxxxxxxx Shaul Hurwitz - shaulh@xxxxxxxx Gary Landis - g_landis@xxxxxxxx ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
