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The influence of episodic shallow magma degassing on heat and chemical transport in volcanic hydrothermal systems

Geophysical Research Letters

By:
ORCID iD , ORCID iD , ORCID iD , ORCID iD , and
https://doi.org/10.1002/2017GL076449

Links

Abstract

Springs at La Soufrière of Guadeloupe have been monitored for nearly four decades since the phreatic eruption and associated seismic activity in 1976. We conceptualize degassing vapor/gas mixtures as square‐wave sources of chloride and heat and apply a new semianalytic solution to demonstrate that chloride and heat pulses with the same timing and duration result in good matches between measured and simulated spring temperatures and concentrations. While the concentration of chloride pulses is variable, the local boiling temperature of 96°C was assigned to all thermal pulses. Because chloride is a conservative tracer, chloride breakthrough is only affected by one‐dimensional advection and dispersion. The thermal tracer is damped and lagged relative to chloride due to conductive heat exchange with the overlying and underlying strata. Joint analysis of temperature and chloride allows estimation of the onset and duration of degassing pulses, refining the chronology of recent magmatic intrusion.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The influence of episodic shallow magma degassing on heat and chemical transport in volcanic hydrothermal systems
Series title:
Geophysical Research Letters
DOI:
10.1002/2017GL076449
Volume:
45
Issue:
7
Year Published:
2018
Language:
English
Publisher:
American Geophysical Union
Contributing office(s):
Oregon Water Science Center
Description:
9 p.
First page:
3068
Last page:
3076