Impact of 3-D Earth structure on W-phase CMT parameters
| Autor: | Catalina Morales-Yáñez, Zacharie Duputel, Luis Rivera |
|---|---|
| Přispěvatelé: | Sismologie (IPGS) (IPGS-Sismologie), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
010504 meteorology & atmospheric sciences
Wave propagation Earthquake source observations Earth structure [SDU.STU]Sciences of the Universe [physics]/Earth Sciences [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] engineering.material 010502 geochemistry & geophysics 01 natural sciences Mantle (geology) Physics::Geophysics Geochemistry and Petrology Inverse theory Seismogram Spherical Earth 0105 earth and related environmental sciences [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics Centroid Small amplitude Geophysics 13. Climate action engineering Structure of the Earth Surface waves and free oscillations Seismology Geology |
| Zdroj: | Geophysical Journal International Geophysical Journal International, Oxford University Press (OUP), 2020, 223 (2), pp.1432-1445. ⟨10.1093/gji/ggaa377⟩ |
| ISSN: | 0956-540X 1365-246X |
| Popis: | SUMMARYWe investigate the impact of unmodelled 3-D structural heterogeneity on inverted W-phase source parameters. We generate a large data set of synthetic seismograms accounting for the Earths 3-D structure for 250 earthquakes globally distributed. The W-phase algorithm is then used to invert for earthquake CMT parameters, assuming a spherical Earth model. The impact of lateral heterogeneity is assessed by comparing inverted source parameters with those used to compute the 3-D synthetics. Results show that the 3-D structure mainly affects centroid location while the effect on the other source parameters remains small. Centroid mislocations present clear geographical patterns. In particular, W-phase solutions for earthquakes in South America are on average biased 17 km to the east of the actual centroid locations. This effect is significantly reduced using an azimuthally well balanced distribution of seismological stations. Source parameters are generally more impacted by mantle heterogeneity while the scalar moment of shallow earthquakes seems to be mainly impacted by the crustal structure. Shallow earthquakes present a variability of Mrθ and Mrϕ moment tensor elements, resulting both from the small amplitude and a larger uncertainty of the associated Green’s functions. |
| Databáze: | OpenAIRE |
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