How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda
Abstract We document the arrival of seismic energy in the core shadow zone up to large distances beyond 150° more than 100 s prior to the core phases. Numerical simulations of the energy transport in an established heterogeneity model show that scattering throughout the entire mantle explains these...
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| Format: | Article |
| Language: | English |
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Wiley
2024-07-01
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| Series: | Geophysical Research Letters |
| Online Access: | https://doi.org/10.1029/2024GL109348 |
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| author | Tuo Zhang Christoph Sens‐Schönfelder Marcelo Bianchi Klaus Bataille |
| author_facet | Tuo Zhang Christoph Sens‐Schönfelder Marcelo Bianchi Klaus Bataille |
| author_sort | Tuo Zhang |
| collection | DOAJ |
| description | Abstract We document the arrival of seismic energy in the core shadow zone up to large distances beyond 150° more than 100 s prior to the core phases. Numerical simulations of the energy transport in an established heterogeneity model show that scattering throughout the entire mantle explains these observations. Diffraction at the core‐mantle boundary is unlikely in our 1–2 Hz frequency band and is not required indicating misleading terminology with reference to Pdiff for the scattered P∗P‐energy. Records of the largest deep earthquakes at low‐noise stations are key to the observation of the faint precursory signal which changes appearance with increasing distance from a coda‐like decay over a constant amplitude level around 130° to an emergent wave train. According to our simulations, different depth layers in the mantle dominate different time‐distance windows of the scattered wave train, providing the opportunity to improve the depth resolution of mantle heterogeneity models. |
| format | Article |
| id | doaj-art-9205da3c395a463e83b966c0d5c6c794 |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2024-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-9205da3c395a463e83b966c0d5c6c7942025-08-20T03:10:25ZengWileyGeophysical Research Letters0094-82761944-80072024-07-015114n/an/a10.1029/2024GL109348How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its CodaTuo Zhang0Christoph Sens‐Schönfelder1Marcelo Bianchi2Klaus Bataille3College of Geophysics Chengdu University of Technology Chengdu ChinaSection 2.4, Deutsches GeoForschungsZentrum GFZ Potsdam GermanyInstituto de Astronomia Geofísica e Ciências Atmosféricas Universidade de São Paulo São Paulo BrazilEarth Sciences Department University of Concepción Concepción ChileAbstract We document the arrival of seismic energy in the core shadow zone up to large distances beyond 150° more than 100 s prior to the core phases. Numerical simulations of the energy transport in an established heterogeneity model show that scattering throughout the entire mantle explains these observations. Diffraction at the core‐mantle boundary is unlikely in our 1–2 Hz frequency band and is not required indicating misleading terminology with reference to Pdiff for the scattered P∗P‐energy. Records of the largest deep earthquakes at low‐noise stations are key to the observation of the faint precursory signal which changes appearance with increasing distance from a coda‐like decay over a constant amplitude level around 130° to an emergent wave train. According to our simulations, different depth layers in the mantle dominate different time‐distance windows of the scattered wave train, providing the opportunity to improve the depth resolution of mantle heterogeneity models.https://doi.org/10.1029/2024GL109348 |
| spellingShingle | Tuo Zhang Christoph Sens‐Schönfelder Marcelo Bianchi Klaus Bataille How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda Geophysical Research Letters |
| title | How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda |
| title_full | How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda |
| title_fullStr | How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda |
| title_full_unstemmed | How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda |
| title_short | How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda |
| title_sort | how p wave scattering throughout the entire mantle mimics the high frequency pdiff and its coda |
| url | https://doi.org/10.1029/2024GL109348 |
| work_keys_str_mv | AT tuozhang howpwavescatteringthroughouttheentiremantlemimicsthehighfrequencypdiffanditscoda AT christophsensschonfelder howpwavescatteringthroughouttheentiremantlemimicsthehighfrequencypdiffanditscoda AT marcelobianchi howpwavescatteringthroughouttheentiremantlemimicsthehighfrequencypdiffanditscoda AT klausbataille howpwavescatteringthroughouttheentiremantlemimicsthehighfrequencypdiffanditscoda |