Three-dimensional seismic velocity tomography of Montserrat from the SEA-CALIPSO offshore/onshore experiment
Kenedi, C. L.
Sparks, R. S. J.
Minshull, T. A.
Date of Issue2010
The SEA-CALIPSO experiment in December 2007 incorporated a sea-based airgun source, and seismic recorders both on Montserrat and on the adjacent sea floor. A high quality subset of the data was used for a first arrival P-wave velocity tomographic study. A total of more than 115,000 traveltime data from 4413 airgun shots, and 58 recording stations, were used in this high-resolution tomographic inversion. The experiment geometry limited the depth of well resolved structures to about 5 km. The most striking features of the tomography are three relatively high velocity zones below each of the main volcanic centers on Montserrat, and three low velocity zones flanking Centre Hills. We suggest that the high velocity zones represent the solid andesitic cores of the volcano complexes, characterized by wave speeds faster than adjacent volcaniclastic material. The low velocity zones may reflect porous volcaniclastic material and/or alteration by formerly active hydrothermal systems.
Geophysical research letters
© 2010 American Geophysical Union. This paper was published in Geophysical Research Letters and is made available as an electronic reprint (preprint) with permission of American Geophysical Union. The paper can be found at: [DOI: http://dx.doi.org/10.1029/2010GL042498]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.