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Nishitsuji, Y. (author), Ruigrok, Elmer (author), Draganov, D.S. (author)The characterization of the megaregolith on the Moon has been investigated in various ways including analysis of lunar meteorites, remote sensing of mineralogy and gravity, and deriving a seismic velocity profile. In this study, we propose a method for analyzing azimuthal anisotropy of the megaregolith. We call this method deep-moonquake...journal article 2020
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Casas, J. A. (author), Draganov, D.S. (author), Badi, G. A. (author), Manassero, M. C. (author), Olivera Craig, V. H. (author), Franco Marín, L. (author), Gómez, M. (author), Ruigrok, E. (author)Although the Planchón-Peteroa Volcanic Complex (PPVC) has undergone many hazardous eruptions, only a small number of geological, geochemical, and geophysical studies have been performed to describe this active volcanic system. In order to characterize the subsurface structures present at the PPVC, we applied seismic interferometry to fracture...journal article 2019
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Martins, Joana E. (author), Ruigrok, Elmer (author), Draganov, D.S. (author), Hooper, A. (author), Hanssen, R.F. (author), White, R.S. (author), Soosalu, Heidi (author)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...journal article 2019
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Hunziker, J.W. (author), Gomez, Martin (author), Wapenaar, C.P.A. (author)Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, the SI responses are retrieved by simple crosscorrelation of recordings made by separate receivers: one of the receivers acts as a ‘virtual source’ whose response is retrieved at the other receivers.When SI is applied...journal article 2017
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Nishitsuji, Y. (author), Ruigrok, E (author), Gomez, M (author), Wapenaar, C.P.A. (author), Draganov, D.S. (author)Obtaining detailed images of aseismic parts of subducting slabs remains a large challenge for understanding slab dynamics. Hypocenter mapping cannot be used for the purpose due to the absence of seismicity, whereas the use of receiver functions might be compromised by the presence of melt. Global tomography can be used to identify the presence...journal article 2016
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, Elmer (author), Huniziker, Jürg (author), Gomez, Martin (author), Wapenaar, C.P.A. (author)Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, these seismic interferometric responses are retrieved by simple crosscorrelation of recordings made by separate receivers: a first receiver acts as a 'virtual source' whose response is retrieved at the other receivers...abstract 2016
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Wapenaar, C.P.A. (author), Gomez, M. (author)Generating new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventially, the new responses are retrieved by simple crosscorrelation of recordings made by separate receivers: a first receiver acts as `virtual source' whose response is retrieved at the other receivers. The newly retrieved...abstract 2016
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Casas, Augusto (author), Draganov, D.S. (author), Olivera Craig, Victoria Hipatia (author), Manassero, Maria Constanza (author), Badi, Gabriela (author), Franco, Luis (author), Ruigrok, E.N. (author), Gomez, Martin (author)Seismic interferometry (SI) retrieves virtual seismic signals from measurements at two receivers from surrounding sources. Studies have demonstrated that SI can image subsurface reflectivity. Claerbout (1968) showed that the reflection response can be obtained by autocorrelating the transmission response assuming a 1-D acoustic medium. Migration...abstract 2016
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Casas, Augusto (author), Draganov, D.S. (author), Olivera Craig, Victoria Hipatia (author), Manassero, Maria Constanza (author), Badi, Gabriela (author), Franco, L (author), Gomez, Martin (author), Ruigrok, E.N. (author)Seismic interferometry (SI) studies the interference phenomenon between pairs of signals in order to obtain information from the differences between them. SI is now regularly used in exploration and global seismology with active and/or passive sources, i.e., artificial sources (dynamite, vibroseis, sledge hammer, etc.) or natural sources ...abstract 2016
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Hunziker, J.W. (author), gomez, Martin (author), Wapenaar, C.P.A. (author)Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, these seismic interferometric responses are retrieved by simple crosscorrelation of recordings made<br/>by separate receivers: a first receiver acts as a 'virtual source' whose response is retrieved at the other...abstract 2016
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- Nishitsuji, Y. (author), Draganov, D.S. (author), Ruigrok, E. (author), Gomez, M. (author), Wapenaar, C.P.A. (author) conference paper 2015
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Nishitsuji, Y. (author), Ruigrok, E. (author), Gomez, M. (author), Draganov, D.S. (author)We investigated the applicability of global phases (epicentral distances of ? 120° and ? 150°) for the H/V spectral ratio to identify the fundamental resonance frequency. We applied the method to delineate a part of Neuquén basin in Argentina without the need for active seismic sources. We obtained fairly identifiable fundamental resonance...conference paper 2015
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- Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author) abstract 2015
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Draganov, D.S. (author), Ruigrok, E.N. (author), Ghose, R. (author), Mikesell, D. (author), Van Wijk, K. (author)We propose a method for estimating the reflection coefficient of a subvertical boundary and the the quality factor of the medium between a receiver and the subvertical boundary. The method uses surface waves from transient deterministic sources and is inspired by the occurrence of non-physical arrivals in seismic-interferometry results due to...conference paper 2014
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Nishitsuji, Y. (author), Ruigrok, E.N. (author), Gomez, M. (author), Draganov, D.S. (author)Structural estimation of unconsolidated sediments and basins is of fundamental importance for resources exploration, geohazard assessments, and other geophysical aspects. The estimation contributes not only to the understanding of the tectonic settings, but also to the choice of parameters for possible further seismic processing, for example,...journal article 2014
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Martins, Joana E. (author), Hooper, Andy (author), Ruigrok, E.N. (author), Draganov, D.S. (author), Hanssen, R.F. (author), White, Robert (author), Soosalu, Heidi (author)Torfajökull is the largest silicic volcanic centre in Iceland lying at the intersection of the rift zone (MidAtlantic Ridge) and the transform zone that connects to Reykjanes peninsula. It erupts infrequently,with only two eruptions in the last 1200 years, the latest of which was over 5 centuries ago. Yet, itsactive tectonic setting, persistent...abstract 2014
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Draganov, D.S. (author), Ghose, R. (author), Heller, K. (author), Ruigrok, E.N. (author)Application of seismic interferometry to records from receivers at the Earth’s surface from sources in wells retrieves the reflection response measured at the receivers as if from virtual sources located also at the surface. When the wavefields experience intrinsic losses during propagation, non-physical arrivals (ghosts) would appear in the...journal article 2012
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Wapenaar, C.P.A. (author), Ruigrok, E.N. (author), Van der Neut, J.R. (author), Draganov, D.S. (author)The methodology of surface?wave retrieval from ambient seismic noise by crosscorrelation relies on the assumption that the noise field is equipartitioned. Deviations from equipartitioning degrade the accuracy of the retrieved surface?wave Green's function. A point?spread function, derived from the same ambient noise field, quantifies the...journal article 2011
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Ruigrok, E.N. (author), Campman, X. (author), Draganov, D.S. (author), Wapenaar, K. (author)In recent years, there has been an increase in the deployment of relatively dense arrays of seismic stations. The availability of spatially densely sampled global and regional seismic data has stimulated the adoption of industry-style imaging algorithms applied to converted- and scattered-wave energy from distant earthquakes, leading to...journal article 2010
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Ruigrok, E.N. (author), Draganov, D.S. (author), Wapenaar, K. (author)Progress in the imaging of the mantle and core is partially limited by the sparse distribution of natural sources; the earthquake hypocenters are mainly along the active lithospheric plate boundaries. This problem can be approached with seismic interferometry. In recent years, there has been considerable progress in the development of seismic...journal article 2008