Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts
Abstract The Kolumbo submarine volcano in the southern Aegean (Greece) is associated with repeated seismic unrest since at least two decades and the causes of this unrest are poorly understood. We present a ten‐month long microseismicity data set for the period 2006–2007. The majority of earthquakes...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2022-07-01
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| Series: | Geochemistry, Geophysics, Geosystems |
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| Online Access: | https://doi.org/10.1029/2022GC010420 |
| _version_ | 1797638058015719424 |
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| author | F. Schmid G. Petersen E. Hooft M. Paulatto K. Chrapkiewicz M. Hensch T. Dahm |
| author_facet | F. Schmid G. Petersen E. Hooft M. Paulatto K. Chrapkiewicz M. Hensch T. Dahm |
| author_sort | F. Schmid |
| collection | DOAJ |
| description | Abstract The Kolumbo submarine volcano in the southern Aegean (Greece) is associated with repeated seismic unrest since at least two decades and the causes of this unrest are poorly understood. We present a ten‐month long microseismicity data set for the period 2006–2007. The majority of earthquakes cluster in a cone‐shaped portion of the crust below Kolumbo. The tip of this cone coincides with a low Vp‐anomaly at 2–4 km depth, which is interpreted as a crustal melt reservoir. Our data set includes several earthquake swarms, of which we analyze the four with the highest events numbers in detail. Together the swarms form a zone of fracturing elongated in the SW‐NE direction, parallel to major regional faults. All four swarms show a general upward migration of hypocenters and the cracking front propagates unusually fast, compared to swarms in other volcanic areas. We conclude that the swarm seismicity is most likely triggered by a combination of pore‐pressure perturbations and the re‐distribution of elastic stresses. Fluid pressure perturbations are induced likely by obstructions in the melt conduits in a rheologically strong layer between 6 and 9 km depth. We conclude that the zone of fractures below Kolumbo is exploited by melts ascending from the mantle and filling the crustal melt reservoir. Together with the recurring seismic unrest, our study suggests that a future eruption is probable and monitoring of the Kolumbo volcanic system is highly advisable. |
| first_indexed | 2024-03-11T12:57:14Z |
| format | Article |
| id | doaj.art-18f03f0bfee94254a791d284cec29c8d |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:57:14Z |
| publishDate | 2022-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-18f03f0bfee94254a791d284cec29c8d2023-11-03T16:56:11ZengWileyGeochemistry, Geophysics, Geosystems1525-20272022-07-01237n/an/a10.1029/2022GC010420Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending MeltsF. Schmid0G. Petersen1E. Hooft2M. Paulatto3K. Chrapkiewicz4M. Hensch5T. Dahm6GEOMAR Helmholtz‐Centre for Ocean Research Kiel Kiel GermanyGFZ Helmholtz‐Centre Potsdam German Research Centre for Geosciences Potsdam Berlin GermanyUniversity of Oregon Eugene OR USAImperial College London Department of Earth Science and Engineering London UKImperial College London Department of Earth Science and Engineering London UKGeological Survey of Baden‐Württemberg Freiburg GermanyGFZ Helmholtz‐Centre Potsdam German Research Centre for Geosciences Potsdam Berlin GermanyAbstract The Kolumbo submarine volcano in the southern Aegean (Greece) is associated with repeated seismic unrest since at least two decades and the causes of this unrest are poorly understood. We present a ten‐month long microseismicity data set for the period 2006–2007. The majority of earthquakes cluster in a cone‐shaped portion of the crust below Kolumbo. The tip of this cone coincides with a low Vp‐anomaly at 2–4 km depth, which is interpreted as a crustal melt reservoir. Our data set includes several earthquake swarms, of which we analyze the four with the highest events numbers in detail. Together the swarms form a zone of fracturing elongated in the SW‐NE direction, parallel to major regional faults. All four swarms show a general upward migration of hypocenters and the cracking front propagates unusually fast, compared to swarms in other volcanic areas. We conclude that the swarm seismicity is most likely triggered by a combination of pore‐pressure perturbations and the re‐distribution of elastic stresses. Fluid pressure perturbations are induced likely by obstructions in the melt conduits in a rheologically strong layer between 6 and 9 km depth. We conclude that the zone of fractures below Kolumbo is exploited by melts ascending from the mantle and filling the crustal melt reservoir. Together with the recurring seismic unrest, our study suggests that a future eruption is probable and monitoring of the Kolumbo volcanic system is highly advisable.https://doi.org/10.1029/2022GC010420aegeanhellenic volcanic arcsantorinisubmarine volcanismearthquake swarms |
| spellingShingle | F. Schmid G. Petersen E. Hooft M. Paulatto K. Chrapkiewicz M. Hensch T. Dahm Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts Geochemistry, Geophysics, Geosystems aegean hellenic volcanic arc santorini submarine volcanism earthquake swarms |
| title | Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts |
| title_full | Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts |
| title_fullStr | Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts |
| title_full_unstemmed | Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts |
| title_short | Heralds of Future Volcanism: Swarms of Microseismicity Beneath the Submarine Kolumbo Volcano Indicate Opening of Near‐Vertical Fractures Exploited by Ascending Melts |
| title_sort | heralds of future volcanism swarms of microseismicity beneath the submarine kolumbo volcano indicate opening of near vertical fractures exploited by ascending melts |
| topic | aegean hellenic volcanic arc santorini submarine volcanism earthquake swarms |
| url | https://doi.org/10.1029/2022GC010420 |
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