Hydrothermal Circulation At Mount St Helens Determined By Self-Potential Measurements

Jump to: navigation, search


OpenEI Reference LibraryAdd to library

Journal Article: Hydrothermal Circulation At Mount St Helens Determined By Self-Potential Measurements

Abstract
The distribution of hydrothermal circulation within active volcanoes is of importance in identifying regions of hydrothermal alteration which may in turn control explosivity, slope stability and sector collapse. Self-potential measurements, indicative of fluid circulation, were made within the crater of Mount St. Helens in 2000 and 2001. A strong dipolar anomaly in the self-potential field was detected on the north face of the 1980-86 lava dome. This anomaly reaches a value of negative one volt on the lower flanks of the dome and reverses sign toward the dome summit. The anomaly pattern is believed to result from a combination of thermoelectric, electrokinetic, and fluid disruption effects within and surrounding the dome. Heat supplied from a cooling dacite magma very likely drives a shallow hydrothermal convection cell within the dome. The temporal stability of the SP field, low surface recharge rate, and magmatic component to fumarole condensates and thermal waters suggest the hydrothermal system is maintained by water vapor exsolved from the magma and modulated on short time scales by surface recharge.

Authors 
Paul A. Bedrosian, Martyn J. Unsworth and Malcolm J. S. Johnston








Published Journal 
Journal of Volcanology and Geothermal Research, 2007





DOI 
Not Provided
Check for DOI availability: http://crossref.org



 

Citation

Paul A. Bedrosian,Martyn J. Unsworth,Malcolm J. S. Johnston. 2007. Hydrothermal Circulation At Mount St Helens Determined By Self-Potential Measurements. Journal of Volcanology and Geothermal Research. (!) .


Related Geothermal Exploration Activities
Activities (1)


Areas (1)
  1. Mt St Helens Area
Regions (0)