Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield
We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. We separate source spectra and site terms and determine intrinsic attenuation and the scattering strength of shear waves in the 3Hz to 200Hz frequency ran...
Published in: | Journal of Geophysical Research: Solid Earth |
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ftdbthueringen:oai:www.db-thueringen.de:dbt_mods_00056982 2024-04-07T07:52:24+00:00 Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield Eulenfeld, Tom Hillers, Gregor Vuorinen, Tommi A. T. Wegler, Ulrich 2023 31 Seiten https://doi.org/10.1029/2022JB025162 https://www.db-thueringen.de/receive/dbt_mods_00056982 https://www.db-thueringen.de/servlets/MCRFileNodeServlet/dbt_derivate_00059942/Eulenfeld2023_earthquake_source_parameters_attenuation_site_effects.pdf eng eng JGR -- Journal of geophysical research -- 2169-9356 https://doi.org/10.1029/2022JB025162 https://www.db-thueringen.de/receive/dbt_mods_00056982 https://www.db-thueringen.de/servlets/MCRFileNodeServlet/dbt_derivate_00059942/Eulenfeld2023_earthquake_source_parameters_attenuation_site_effects.pdf https://creativecommons.org/licenses/by/4.0/ public info:eu-repo/semantics/openAccess article ScholarlyArticle ddc:550 Seismic attenuation -- wave scattering and diffraction -- induced earthquakes -- earthquake source observations -- site effects -- Fennoscandian Shield article Text doc-type:Article 2023 ftdbthueringen https://doi.org/10.1029/2022JB025162 2024-03-08T13:27:26Z We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. We separate source spectra and site terms and determine intrinsic attenuation and the scattering strength of shear waves in the 3Hz to 200Hz frequency range using radiative transfer based synthetic envelopes. Displacement spectra yield scaling relations with a general deviation from self-similarity, with a stronger albeit more controversial signal from the weaker 2020 stimulation. The 2020 earthquakes also tend to have a smaller local magnitude compared to 2018 earthquakes with the same moment magnitude. We discuss these connections in the context of fluid effects on rupture speed or medium properties. Site terms demonstrate that the spectral amplification relative to two reference borehole sites is not neutral at the other sensors; largest variations are observed at surface stations at frequencies larger than 30Hz. Intrinsic attenuation is exceptionally low with Qi-1 values down to 2.4x10-5 at 20Hz, which allows the observation of a diffuse reflection at the ~50km deep Moho. Scattering strength is in the range of globally observed data with Qsc-1 between 10-3 and 10-4. The application of the employed Qopen analysis program to the 2020 data in a retrospective monitoring mode demonstrates its versatility as a seismicity processing tool. The diverse results have implications for scaling relations, hazard assessment and ground motion modeling, and imaging and monitoring using ballistic and scattered wavefields in the crystalline Fennoscandian Shield environment. Article in Journal/Newspaper Fennoscandian Digital Library Thüringen Journal of Geophysical Research: Solid Earth 128 4 |
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Digital Library Thüringen |
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ftdbthueringen |
language |
English |
topic |
article ScholarlyArticle ddc:550 Seismic attenuation -- wave scattering and diffraction -- induced earthquakes -- earthquake source observations -- site effects -- Fennoscandian Shield |
spellingShingle |
article ScholarlyArticle ddc:550 Seismic attenuation -- wave scattering and diffraction -- induced earthquakes -- earthquake source observations -- site effects -- Fennoscandian Shield Eulenfeld, Tom Hillers, Gregor Vuorinen, Tommi A. T. Wegler, Ulrich Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield |
topic_facet |
article ScholarlyArticle ddc:550 Seismic attenuation -- wave scattering and diffraction -- induced earthquakes -- earthquake source observations -- site effects -- Fennoscandian Shield |
description |
We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. We separate source spectra and site terms and determine intrinsic attenuation and the scattering strength of shear waves in the 3Hz to 200Hz frequency range using radiative transfer based synthetic envelopes. Displacement spectra yield scaling relations with a general deviation from self-similarity, with a stronger albeit more controversial signal from the weaker 2020 stimulation. The 2020 earthquakes also tend to have a smaller local magnitude compared to 2018 earthquakes with the same moment magnitude. We discuss these connections in the context of fluid effects on rupture speed or medium properties. Site terms demonstrate that the spectral amplification relative to two reference borehole sites is not neutral at the other sensors; largest variations are observed at surface stations at frequencies larger than 30Hz. Intrinsic attenuation is exceptionally low with Qi-1 values down to 2.4x10-5 at 20Hz, which allows the observation of a diffuse reflection at the ~50km deep Moho. Scattering strength is in the range of globally observed data with Qsc-1 between 10-3 and 10-4. The application of the employed Qopen analysis program to the 2020 data in a retrospective monitoring mode demonstrates its versatility as a seismicity processing tool. The diverse results have implications for scaling relations, hazard assessment and ground motion modeling, and imaging and monitoring using ballistic and scattered wavefields in the crystalline Fennoscandian Shield environment. |
format |
Article in Journal/Newspaper |
author |
Eulenfeld, Tom Hillers, Gregor Vuorinen, Tommi A. T. Wegler, Ulrich |
author_facet |
Eulenfeld, Tom Hillers, Gregor Vuorinen, Tommi A. T. Wegler, Ulrich |
author_sort |
Eulenfeld, Tom |
title |
Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield |
title_short |
Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield |
title_full |
Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield |
title_fullStr |
Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield |
title_full_unstemmed |
Induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the Fennoscandian Shield |
title_sort |
induced earthquake source parameters, attenuation, and site effects from waveform envelopes in the fennoscandian shield |
publishDate |
2023 |
url |
https://doi.org/10.1029/2022JB025162 https://www.db-thueringen.de/receive/dbt_mods_00056982 https://www.db-thueringen.de/servlets/MCRFileNodeServlet/dbt_derivate_00059942/Eulenfeld2023_earthquake_source_parameters_attenuation_site_effects.pdf |
genre |
Fennoscandian |
genre_facet |
Fennoscandian |
op_relation |
JGR -- Journal of geophysical research -- 2169-9356 https://doi.org/10.1029/2022JB025162 https://www.db-thueringen.de/receive/dbt_mods_00056982 https://www.db-thueringen.de/servlets/MCRFileNodeServlet/dbt_derivate_00059942/Eulenfeld2023_earthquake_source_parameters_attenuation_site_effects.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ public info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2022JB025162 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
128 |
container_issue |
4 |
_version_ |
1795667724149456896 |