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The shallow structure beneath Montserrat (West Indies) from new Bouguer gravity data
Author(s) -
Hautmann Stefanie,
Camacho Antonio G.,
Gottsmann Joachim,
Odbert Henry M.,
Syers R. Tappy
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.51003
Subject(s) - geology , bouguer anomaly , volcano , seismology , pyroclastic rock , gravity anomaly , tectonics , geomorphology , geophysics , paleontology , oil field
Although the persistently active Soufrière Hills Volcano (Montserrat, West Indies) is one of the most extensively studied active stratovolcanoes, a local Bouguer gravity map of the volcano and the island of Montserrat has yet to be constructed. We collected 157 new gravity data, which we analyzed and inverted in order to constrain the island's subsurface density distribution. Our model results reveal high‐density material beneath the centers of the extinct volcanic complexes—presumably related to exposed dome cores—while the volcanic flanks and the active Soufrière Hills Volcano are underlain by low‐density material. Volcaniclastic deposits and subsurface melt aggregations, respectively, may explain these negative gravity anomalies. Our results are in good agreement with previous structural observations from seismic tomography; however, a higher spatial density of the gravity survey network has allowed us to additionally capture smaller, shallow‐seated anomalies in the gravity field that relate to tectonic structures and fluvial filling deposits.