Seasonal modulation of oceanic seismicity in the azores
The analysis of an 11-year (2008–2018) seismic catalogue of the Azores suggests the existence of secondary cyclic influences on the seismicity rate of the oceanic region, with more earthquakes observed during the summer months, from May to August, than in winter. Statistical testing based on Monte-C...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-12-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.995401/full |
| _version_ | 1828171704103337984 |
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| author | Ana L. Lordi Ana L. Lordi Maria C. Neves Maria C. Neves Susana Custódio Susana Custódio Stéphanie Dumont Stéphanie Dumont |
| author_facet | Ana L. Lordi Ana L. Lordi Maria C. Neves Maria C. Neves Susana Custódio Susana Custódio Stéphanie Dumont Stéphanie Dumont |
| author_sort | Ana L. Lordi |
| collection | DOAJ |
| description | The analysis of an 11-year (2008–2018) seismic catalogue of the Azores suggests the existence of secondary cyclic influences on the seismicity rate of the oceanic region, with more earthquakes observed during the summer months, from May to August, than in winter. Statistical testing based on Monte-Carlo simulations and a Jack-Knife methodology indicate that the seasonal modulation affects earthquakes with magnitudes M3.3–4.5, well above the magnitude of completeness. Here, we investigate the seasonal variations of earthquake rate considering both the whole Azores oceanic domain and four separate sub-regions, corresponding to four regional clusters identified by previous authors. The analysis shows that the seasonal modulation is particularly observed near the Triple Junction region between the Faial Island and the Mid-Atlantic Ridge. To identify possible mechanisms driving the seasonal modulation, we apply Singular Spectral Analysis to the seismicity rate and to time-series of plausible external triggers, in order to investigate possible common periodicities. We find significant correlations between the earthquake rate, sea level anomaly rate, GRACE satellite anomalies and ocean bottom pressure, suggesting that water load may modulate the Azores oceanic seismicity. |
| first_indexed | 2024-04-12T03:30:59Z |
| format | Article |
| id | doaj.art-46ac6171f0d64b479d3dc9962e6045e3 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-12T03:30:59Z |
| publishDate | 2022-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-46ac6171f0d64b479d3dc9962e6045e32022-12-22T03:49:34ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-12-011010.3389/feart.2022.995401995401Seasonal modulation of oceanic seismicity in the azoresAna L. Lordi0Ana L. Lordi1Maria C. Neves2Maria C. Neves3Susana Custódio4Susana Custódio5Stéphanie Dumont6Stéphanie Dumont7Instituto Dom Luiz, University of Lisbon, Lisbon, PortugalUniversity of the Algarve, Faro, PortugalInstituto Dom Luiz, University of Lisbon, Lisbon, PortugalUniversity of the Algarve, Faro, PortugalInstituto Dom Luiz, University of Lisbon, Lisbon, PortugalUniversity of Lisbon, Lisbon, PortugalInstituto Dom Luiz, University of Lisbon, Lisbon, PortugalUniversity of Beira Interior, Covilhã, PortugalThe analysis of an 11-year (2008–2018) seismic catalogue of the Azores suggests the existence of secondary cyclic influences on the seismicity rate of the oceanic region, with more earthquakes observed during the summer months, from May to August, than in winter. Statistical testing based on Monte-Carlo simulations and a Jack-Knife methodology indicate that the seasonal modulation affects earthquakes with magnitudes M3.3–4.5, well above the magnitude of completeness. Here, we investigate the seasonal variations of earthquake rate considering both the whole Azores oceanic domain and four separate sub-regions, corresponding to four regional clusters identified by previous authors. The analysis shows that the seasonal modulation is particularly observed near the Triple Junction region between the Faial Island and the Mid-Atlantic Ridge. To identify possible mechanisms driving the seasonal modulation, we apply Singular Spectral Analysis to the seismicity rate and to time-series of plausible external triggers, in order to investigate possible common periodicities. We find significant correlations between the earthquake rate, sea level anomaly rate, GRACE satellite anomalies and ocean bottom pressure, suggesting that water load may modulate the Azores oceanic seismicity.https://www.frontiersin.org/articles/10.3389/feart.2022.995401/fulloceanic seismicityseasonal modulationazoresvolcano-tectonic systemsmid-atlantic ridge |
| spellingShingle | Ana L. Lordi Ana L. Lordi Maria C. Neves Maria C. Neves Susana Custódio Susana Custódio Stéphanie Dumont Stéphanie Dumont Seasonal modulation of oceanic seismicity in the azores Frontiers in Earth Science oceanic seismicity seasonal modulation azores volcano-tectonic systems mid-atlantic ridge |
| title | Seasonal modulation of oceanic seismicity in the azores |
| title_full | Seasonal modulation of oceanic seismicity in the azores |
| title_fullStr | Seasonal modulation of oceanic seismicity in the azores |
| title_full_unstemmed | Seasonal modulation of oceanic seismicity in the azores |
| title_short | Seasonal modulation of oceanic seismicity in the azores |
| title_sort | seasonal modulation of oceanic seismicity in the azores |
| topic | oceanic seismicity seasonal modulation azores volcano-tectonic systems mid-atlantic ridge |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.995401/full |
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