Print Email Facebook Twitter Imaging Torfajökull's Magmatic Plumbing System With Seismic Interferometry and Phase Velocity Surface Wave Tomography Title Imaging Torfajökull's Magmatic Plumbing System With Seismic Interferometry and Phase Velocity Surface Wave Tomography Author Martins, Joana E. (TU Delft Mathematical Geodesy and Positioning; TNO) Ruigrok, Elmer (Universiteit Utrecht; Royal Netherlands Meteorological Institute (KNMI)) Draganov, D.S. (TU Delft Applied Geophysics and Petrophysics) Hooper, A. (University of Leeds) Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning) White, R.S. (University of Cambridge) Soosalu, Heidi (University of Cambridge; Geological Survey of Estonia) Date 2019 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. Subject 3-D S wave velocityambient noise tomography (ANT)low-velocity anomaliesseismic interferometryTorfajokull volcanovolcano caldera To reference this document use: http://resolver.tudelft.nl/uuid:4a7d5784-f0be-417b-8501-792a877fc7fa DOI https://doi.org/10.1029/2018JB016002 ISSN 2169-9313 Source JGR Solid Earth, 124 (3), 2920-2940 Part of collection Institutional Repository Document type journal article Rights © 2019 Joana E. Martins, Elmer Ruigrok, D.S. Draganov, A. Hooper, R.F. Hanssen, R.S. White, Heidi Soosalu Files PDF Martins_et_al_2019_Journa ... _Earth.pdf 7.38 MB Close viewer /islandora/object/uuid:4a7d5784-f0be-417b-8501-792a877fc7fa/datastream/OBJ/view