Martins, JE, Ruigrok, E, Draganov, D et al. (4 more authors) (2019) Imaging Torfajökull's Magmatic Plumbing System With Seismic Interferometry and Phase Velocity Surface Wave Tomography. Journal of Geophysical Research: Solid Earth, 124 (3). pp. 2920-2940. ISSN 2169-9356
Abstract
Torfajökull volcano, Iceland, has not erupted since 1477. However, intense geothermal activity, deformation, and seismicity suggest a long-lasting magmatic system. In this paper, we use ambient noise tomography to image the magmatic system beneath Torfajökull volcano. One hundred days of ambient noise data from 23 broadband seismometers show the consistent presence of double-frequency microseism noise with significant power between ∼0.1 and 0.5 Hz. Beamforming results indicate microseism noise with persistent higher energy propagating from west and SE directions and apparent velocities below 3 km/s. We use ambient noise seismic interferometry to retrieve Rayleigh waves, and we introduce a method to estimate the reliability of the retrieved surface waves. We find stable estimation of surface wave phase velocities between 0.16 and 0.38 Hz. Azimuthal velocity variations show a trend of higher velocities in the NE/SW direction, the strike of the rift zone intersecting Torfajökull, and orientation of erupted lavas on a NE-SW fissure swarm. Tomographic results indicate low-velocity anomalies beneath the volcano caldera (between −5% and −10%) and even lower velocity variations in the southeast and southwest study area (below −10%), outside the volcano caldera. Low anomalies may indicate the existence of hot material, more prominent outside the caldera outskirts. High-velocity variations (between 5% and 10%) outline the volcano caldera between 4- and 5-km depth and more pronounced velocities (between 10% and 15%) up to 5-km depth in the north of the volcano caldera. We interpret the former as possible caldera collapse structure and the latest as solidified intrusive magma from the old preferred magma paths.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. See: https://creativecommons.org/licenses/by-nc-nd/4.0/ |
Keywords: | ambient noise tomography (ANT); Torfajokull volcano; 3‐D S wave velocity; seismic interferometry; low‐velocity anomalies; volcano caldera |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 11 Apr 2019 11:08 |
Last Modified: | 25 Jun 2023 21:47 |
Status: | Published |
Publisher: | American Geophysical Union |
Identification Number: | 10.1029/2018JB016002 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:144807 |
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