Abstract
Determining the spatial relations between volcanic edifices and their underlying magma storage zones is fundamental for characterizing long-term evolution and short-term unrest. We compile centroid locations of upper crustal magma reservoirs at 56 arc volcanoes inferred from seismic, magnetotelluric, and geodetic studies. We show that magma reservoirs are often horizontally offset from their associated volcanic edifices by multiple kilometers, and the degree of offset broadly scales with reservoir depth. Approximately 20% of inferred magma reservoir centroids occur outside of the overlying volcano's mean radius. Furthermore, reservoir offset is inversely correlated with edifice size. Taking edifice volume as a proxy for long-term magmatic flux, we suggest that high flux or prolonged magmatism leads to more centralized magma storage beneath arc volcanoes by overprinting upper crustal heterogeneities that would otherwise affect magma ascent. Edifice volumes therefore reflect the spatial distribution of underlying magma storage, which could help guide monitoring strategies at volcanoes.
| Original language | English |
|---|---|
| Article number | e2020GL087856 |
| Journal | Geophysical Research Letters |
| Volume | 47 |
| Issue number | 14 |
| DOIs | |
| Publication status | Published - 28 Jul 2020 |
Bibliographical note
Funding Information:A. H. L. and D. O. acknowledge support from the National Science Foundation Graduate Research Fellowship Program under Grant 1309047. L. K. acknowledges funding through NSF CAREER 1848554. S. K. E. is supported by a UKRI NERC Independent Research Fellowship and also acknowledges a European Space Agency Living Planet Fellowship and the NERC‐BGS Centre for Observation and Modeling of Earthquakes, Volcanoes, and Tectonics (COMET). K. R. A. and S. H. were funded by the U.S. Geological Survey's Volcano Hazards Program. A. L. thanks the University of Oregon geophysics community for many fruitful discussions on tomography methodology and interpretation. We thank Mike Poland and two anonymous reviewers for constructive comments that significantly improved this manuscript, and thank Chris Huber for editorial handling. Any use of trade, firm, or product names is for descriptive purposes and does not imply endorsement by the U.S. Government. We declare no competing interests.
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©2020. American Geophysical Union. All Rights Reserved.
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Copyright 2020 Elsevier B.V., All rights reserved.