دورية أكاديمية
Azimuthal anisotropy from Eikonal Tomography: example from ambient-noise measurements in the AlpArray network
| العنوان: | Azimuthal anisotropy from Eikonal Tomography: example from ambient-noise measurements in the AlpArray network |
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| المؤلفون: | Kästle, Emanuel, Molinari, Irene, Boschi, Lapo, Kissling, Edi, AlpArray Working Group |
| المساهمون: | Institute for Geological Sciences, Freie Universität Berlin, Germany, Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Bologna, Bologna, Italia, Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Italy, Dipartimento di Geoscienze, Universitá degli Studi di Padova, Italy, Institut des Sciences de la Terre Paris, Sorbonne Université, CNRS-INSU, ISTeP UMR 7193, F-75005 Paris, France, Department of Earth Sciences, ETH Zürich, Switzerland, www.alparray.ethz.ch |
| بيانات النشر: | Oxford University Press |
| سنة النشر: | 2022 |
| المجموعة: | Earth-Prints (Istituto Nazionale di Geofisica e Vulcanologia) |
| مصطلحات موضوعية: | Seismic anisotropy, Seismic interferometry, Seismic tomography, Wave propagation, Continental tectonics: compressional, 04.01. Earth Interior, 04.06. Seismology |
| الوصف: | This article has been accepted for publication in Geophysical Journal International ©: The Authors 2021. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Uploaded in accordance with the publisher's self-archiving policy. ; Ambient-noise records from the AlpArray network are used to measure Rayleigh wave phase velocities between more than 150,000 station pairs. From these, azimuthally anisotropic phase-velocity maps are obtained by applying the Eikonal tomography method. Several synthetic tests are shown to study the bias in the Ψ2 anisotropy. There are two main groups of bias, the first one caused by interference between refracted/reflected waves and the appearance of secondary wavefronts that affect the phase travel-time measurements. This bias can be reduced if the amplitude field can be estimated correctly. Another source of error is related to the incomplete reconstruction of the travel-time field that is only sparsely sampled due to the receiver locations. Both types of bias scale with the magnitude of the velocity heterogeneities. Most affected by the spurious Ψ2 anisotropy are areas inside and at the border of low-velocity zones. In the isotropic velocity distribution, most of the bias cancels out if the azimuthal coverage is good. Despite the lack of resolution in many parts of the surveyed area, we identify a number of anisotropic structures that are robust: in the central Alps, we find a layered anisotropic structure, arc-parallel at midcrustal depths and arc-perpendicular in the lower crust. In contrast, in the eastern Alps, the pattern is more consistently E-W oriented which we relate to the eastward extrusion. The northern Alpine forleand exhibits a preferential anisotropic orientation that is similar to SKS observations in the lowermost crust and uppermost mantle. ; German Science Foundation (SPP-2017, Project Ha 2403/21-1); Swiss National Science Foundation SINERGIA Project CRSII2-154434/1 (Swiss-AlpArray); Progetto Pianeta Dinamico, ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| تدمد: | 0956-540X |
| العلاقة: | Geophysical Journal International; 1/229 (2022); http://hdl.handle.net/2122/15034Test |
| DOI: | 10.1093/gji/ggab453 |
| الإتاحة: | https://doi.org/10.1093/gji/ggab453Test http://hdl.handle.net/2122/15034Test |
| حقوق: | open |
| رقم الانضمام: | edsbas.D8327F4A |
| قاعدة البيانات: | BASE |
| تدمد: | 0956540X |
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| DOI: | 10.1093/gji/ggab453 |