Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology
The Global Seismographic Network (GSN)—a global network of ≈150 very broadband stations—is used by researchers to study the free oscillations of the Earth (≈0.3–10 mHz) following large earthquakes. Normal-mode observations can provide information about the radial density and anisotropic velocity str...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Seismological Society of America
2022-04-01
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| Series: | The Seismic Record |
| Online Access: | https://doi.org/10.1785/0320220008 |
| _version_ | 1797347613829234688 |
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| author | Adam T. Ringler Robert E. Anthony Peter Davis Carl Ebeling Katrin Hafner Robert Mellors Simon Schneider David C. Wilson |
| author_facet | Adam T. Ringler Robert E. Anthony Peter Davis Carl Ebeling Katrin Hafner Robert Mellors Simon Schneider David C. Wilson |
| author_sort | Adam T. Ringler |
| collection | DOAJ |
| description | The Global Seismographic Network (GSN)—a global network of ≈150 very broadband stations—is used by researchers to study the free oscillations of the Earth (≈0.3–10 mHz) following large earthquakes. Normal-mode observations can provide information about the radial density and anisotropic velocity structure of the Earth (including near the core–mantle boundary), but only when signal-to-noise ratios at very low frequencies are sufficiently high. Most normal-mode observations in the past three decades have been made using Streckeisen STS-1 vault seismometers. However, these sensors are no longer being manufactured or serviced. Candidate replacement sensors, the Streckeisen STS-6 and the Nanometrics T-360GSN, have been recently installed in boreholes, postholes, and vaults at several GSN stations and GSN testbeds. In this study, we examine normal-mode spectra following three Mw 8 earthquakes in 2021 and from one Mw 8.2 earthquake in 2014 to evaluate the change in GSN low-frequency performance on the vertical component. From this analysis, we conclude that the number of GSN stations capable of resolving normal modes following Mw 8 earthquakes has nearly doubled since 2014. The improved observational capabilities will help better understand the radial velocity and density estimates of the Earth. |
| first_indexed | 2024-03-08T11:50:19Z |
| format | Article |
| id | doaj.art-5b1ef7cc278642fb8ea275e802cdb18a |
| institution | Directory Open Access Journal |
| issn | 2694-4006 |
| language | English |
| last_indexed | 2024-03-08T11:50:19Z |
| publishDate | 2022-04-01 |
| publisher | Seismological Society of America |
| record_format | Article |
| series | The Seismic Record |
| spelling | doaj.art-5b1ef7cc278642fb8ea275e802cdb18a2024-01-24T13:07:14ZengSeismological Society of AmericaThe Seismic Record2694-40062022-04-0122788710.1785/032022000822008Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency SeismologyAdam T. Ringler0https://orcid.org/0000-0002-9839-4188Robert E. Anthony1https://orcid.org/0000-0001-7089-8846Peter Davis2https://orcid.org/0000-0003-0722-590XCarl Ebeling3https://orcid.org/0000-0001-5032-3615Katrin Hafner4Robert Mellors5https://orcid.org/0000-0002-2723-5163Simon Schneider6David C. Wilson7https://orcid.org/0000-0003-2582-5159U.S. Geological Survey, Albuquerque Seismological Laboratory, Albuquerque, New Mexico, U.S.A.U.S. Geological Survey, Albuquerque Seismological Laboratory, Albuquerque, New Mexico, U.S.A.Project IDA, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, U.S.A.Project IDA, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, U.S.A.Incorporated Institutions for Seismology, Washington, District of Columbia, U.S.A.Project IDA, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, U.S.A.Royal Netherlands Meteorological Institute (KNMI), De Bilt, NetherlandsU.S. Geological Survey, Albuquerque Seismological Laboratory, Albuquerque, New Mexico, U.S.A.The Global Seismographic Network (GSN)—a global network of ≈150 very broadband stations—is used by researchers to study the free oscillations of the Earth (≈0.3–10 mHz) following large earthquakes. Normal-mode observations can provide information about the radial density and anisotropic velocity structure of the Earth (including near the core–mantle boundary), but only when signal-to-noise ratios at very low frequencies are sufficiently high. Most normal-mode observations in the past three decades have been made using Streckeisen STS-1 vault seismometers. However, these sensors are no longer being manufactured or serviced. Candidate replacement sensors, the Streckeisen STS-6 and the Nanometrics T-360GSN, have been recently installed in boreholes, postholes, and vaults at several GSN stations and GSN testbeds. In this study, we examine normal-mode spectra following three Mw 8 earthquakes in 2021 and from one Mw 8.2 earthquake in 2014 to evaluate the change in GSN low-frequency performance on the vertical component. From this analysis, we conclude that the number of GSN stations capable of resolving normal modes following Mw 8 earthquakes has nearly doubled since 2014. The improved observational capabilities will help better understand the radial velocity and density estimates of the Earth.https://doi.org/10.1785/0320220008 |
| spellingShingle | Adam T. Ringler Robert E. Anthony Peter Davis Carl Ebeling Katrin Hafner Robert Mellors Simon Schneider David C. Wilson Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology The Seismic Record |
| title | Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology |
| title_full | Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology |
| title_fullStr | Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology |
| title_full_unstemmed | Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology |
| title_short | Improved Resolution across the Global Seismographic Network: A New Era in Low-Frequency Seismology |
| title_sort | improved resolution across the global seismographic network a new era in low frequency seismology |
| url | https://doi.org/10.1785/0320220008 |
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