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Eruption prediction aided by electronic tiltmeter data at mount st. Helens.
Science (New York, N.Y.)
|September 30, 1983
Summary
Electronic tiltmeters accurately predicted Mount St. Helens effusive eruptions by detecting crater floor tilting. Magma intrusions caused uplift, followed by subsidence just before lava extrusion.
Area of Science:
- Volcanology
- Geophysics
Background:
- Mount St. Helens experienced effusive eruptions between June 1981 and August 1982.
- Understanding eruption precursors is crucial for volcanic hazard assessment.
Purpose of the Study:
- To assess the efficacy of electronic tiltmeter telemetry in predicting effusive volcanic eruptions.
- To analyze the deformation patterns preceding magma extrusion events.
Main Methods:
- Deployment of electronic tiltmeters within the Mount St. Helens crater.
- Continuous monitoring of ground tilt data.
- Correlation of tiltmeter readings with eruption timing.
Main Results:
- Telemetry data accurately predicted all six effusive eruptions during the study period.
- Pre-eruption tilt patterns included several weeks of initial tilting, followed by sharp acceleration, and then a directional change before extrusion.
- Uplift episodes were linked to shallow magma intrusions inflating the lava dome.
Conclusions:
- Electronic tiltmeters provide reliable short-term predictions for effusive eruptions.
- Observed deformation patterns (uplift and subsidence) are direct indicators of shallow magma movement and dome pressurization.
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