Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals
Mt. Vesuvius is a high-hazard active volcano surrounded by a densely populated area. Since human activities generate high levels of seismic noise, recognizing low-amplitude seismic events in the signals recorded by the local seismic monitoring network operating at Vesuvius is very difficult. Here, w...
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| Format: | Article |
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MDPI AG
2022-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/1/194 |
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| author | Danilo Galluzzo Roberto Manzo Mario La Rocca Lucia Nardone Rosa Di Maio |
| author_facet | Danilo Galluzzo Roberto Manzo Mario La Rocca Lucia Nardone Rosa Di Maio |
| author_sort | Danilo Galluzzo |
| collection | DOAJ |
| description | Mt. Vesuvius is a high-hazard active volcano surrounded by a densely populated area. Since human activities generate high levels of seismic noise, recognizing low-amplitude seismic events in the signals recorded by the local seismic monitoring network operating at Vesuvius is very difficult. Here, we describe an automatic procedure applied to continuous data with the aim of finding low-amplitude–low-frequency events hidden in the recorded signals. The methodology is based on the computation of two spectral parameters, central frequency <i>Ω</i> and shape factor <i>ẟ</i>, at selected sites, and the coherence of the seismic signal among different sites. The proposed procedure is applied to 28 months of recordings from 2019 to 2021, tuning the search parameters in order to find low-frequency signals similar to those occasionally observed in the past at the same volcano. The results allowed us to identify 80 seismic events that have the spectral features of low-frequency earthquakes or tremor. Among these, 12 events characterized by sufficiently high signal-to-noise ratio have been classified as deep low-frequency earthquakes, most of which are not reported in the catalog. The remaining events (more than 60) are characterized by similar spectral features but with an extremely low amplitude that prevents any reliable location of the source and definitive classification. The results of this work demonstrate that the low-frequency endogenous activity at Mt. Vesuvius volcano is more frequent that previously thought. |
| first_indexed | 2024-03-11T10:08:38Z |
| format | Article |
| id | doaj.art-1fc3bc2deb134fb89460274c281d1a9e |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-11T10:08:38Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-1fc3bc2deb134fb89460274c281d1a9e2023-11-16T14:51:56ZengMDPI AGApplied Sciences2076-34172022-12-0113119410.3390/app13010194Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic SignalsDanilo Galluzzo0Roberto Manzo1Mario La Rocca2Lucia Nardone3Rosa Di Maio4Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli, Osservatorio Vesuviano, 80124 Naples, ItalyDipartimento di Scienze Della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, 80126 Naples, ItalyDipartimento di Fisica, Università della Calabria, 87036 Rende, ItalyIstituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli, Osservatorio Vesuviano, 80124 Naples, ItalyDipartimento di Scienze Della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, 80126 Naples, ItalyMt. Vesuvius is a high-hazard active volcano surrounded by a densely populated area. Since human activities generate high levels of seismic noise, recognizing low-amplitude seismic events in the signals recorded by the local seismic monitoring network operating at Vesuvius is very difficult. Here, we describe an automatic procedure applied to continuous data with the aim of finding low-amplitude–low-frequency events hidden in the recorded signals. The methodology is based on the computation of two spectral parameters, central frequency <i>Ω</i> and shape factor <i>ẟ</i>, at selected sites, and the coherence of the seismic signal among different sites. The proposed procedure is applied to 28 months of recordings from 2019 to 2021, tuning the search parameters in order to find low-frequency signals similar to those occasionally observed in the past at the same volcano. The results allowed us to identify 80 seismic events that have the spectral features of low-frequency earthquakes or tremor. Among these, 12 events characterized by sufficiently high signal-to-noise ratio have been classified as deep low-frequency earthquakes, most of which are not reported in the catalog. The remaining events (more than 60) are characterized by similar spectral features but with an extremely low amplitude that prevents any reliable location of the source and definitive classification. The results of this work demonstrate that the low-frequency endogenous activity at Mt. Vesuvius volcano is more frequent that previously thought.https://www.mdpi.com/2076-3417/13/1/194low-frequency earthquakessignal detectionvolcano seismicityspectral parameterscoherence analysis |
| spellingShingle | Danilo Galluzzo Roberto Manzo Mario La Rocca Lucia Nardone Rosa Di Maio Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals Applied Sciences low-frequency earthquakes signal detection volcano seismicity spectral parameters coherence analysis |
| title | Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals |
| title_full | Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals |
| title_fullStr | Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals |
| title_full_unstemmed | Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals |
| title_short | Detection of Low Frequency Seismicity at Mt. Vesuvius Based on Coherence and Statistical Moments of Seismic Signals |
| title_sort | detection of low frequency seismicity at mt vesuvius based on coherence and statistical moments of seismic signals |
| topic | low-frequency earthquakes signal detection volcano seismicity spectral parameters coherence analysis |
| url | https://www.mdpi.com/2076-3417/13/1/194 |
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