Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity

The identification of the mechanisms responsible for the deformation of calderas is of primary importance for our understanding of the dynamics of magmatic systems and the evaluation of volcanic hazards. We analyze twenty years (1997–2018) of geodetic measurements on Ischia Island (Italy), which inc...

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Main Authors: Alessandro Galvani, Giuseppe Pezzo, Vincenzo Sepe, Guido Ventura
Format: Article
Language:English
Published: MDPI AG 2021-11-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/13/22/4648
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author Alessandro Galvani
Giuseppe Pezzo
Vincenzo Sepe
Guido Ventura
author_facet Alessandro Galvani
Giuseppe Pezzo
Vincenzo Sepe
Guido Ventura
author_sort Alessandro Galvani
collection DOAJ
description The identification of the mechanisms responsible for the deformation of calderas is of primary importance for our understanding of the dynamics of magmatic systems and the evaluation of volcanic hazards. We analyze twenty years (1997–2018) of geodetic measurements on Ischia Island (Italy), which include the Mt. Epomeo resurgent block, and is affected by hydrothermal manifestations and shallow seismicity. The data from the GPS Network and the leveling route show a constant subsidence with values up to −15 ± 2.0 mm/yr and a centripetal displacement rate with the largest deformations on the southern flank of Mt. Epomeo. The joint inversion of GPS and levelling data is consistent with a 4 km deep source deflating by degassing and magma cooling below the southern flank of Mt. Epomeo. The depth of the source is supported by independent geophysical data. The Ischia deformation field is not related to the instability of the resurgent block or extensive gravity or tectonic processes. The seismicity reflects the dynamics of the shallow hydrothermal system being neither temporally nor spatially related to the deflation.
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spelling doaj.art-90bc59f02c0749af80b95c6d4d8f00862023-11-23T01:20:55ZengMDPI AGRemote Sensing2072-42922021-11-011322464810.3390/rs13224648Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with SeismicityAlessandro Galvani0Giuseppe Pezzo1Vincenzo Sepe2Guido Ventura3Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, ItalyIstituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, ItalyIstituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, ItalyIstituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, ItalyThe identification of the mechanisms responsible for the deformation of calderas is of primary importance for our understanding of the dynamics of magmatic systems and the evaluation of volcanic hazards. We analyze twenty years (1997–2018) of geodetic measurements on Ischia Island (Italy), which include the Mt. Epomeo resurgent block, and is affected by hydrothermal manifestations and shallow seismicity. The data from the GPS Network and the leveling route show a constant subsidence with values up to −15 ± 2.0 mm/yr and a centripetal displacement rate with the largest deformations on the southern flank of Mt. Epomeo. The joint inversion of GPS and levelling data is consistent with a 4 km deep source deflating by degassing and magma cooling below the southern flank of Mt. Epomeo. The depth of the source is supported by independent geophysical data. The Ischia deformation field is not related to the instability of the resurgent block or extensive gravity or tectonic processes. The seismicity reflects the dynamics of the shallow hydrothermal system being neither temporally nor spatially related to the deflation.https://www.mdpi.com/2072-4292/13/22/4648GNSSvelocity fieldresurgent calderasubsidenceearthquakesdegassing processes
spellingShingle Alessandro Galvani
Giuseppe Pezzo
Vincenzo Sepe
Guido Ventura
Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity
Remote Sensing
GNSS
velocity field
resurgent caldera
subsidence
earthquakes
degassing processes
title Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity
title_full Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity
title_fullStr Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity
title_full_unstemmed Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity
title_short Shrinking of Ischia Island (Italy) from Long-Term Geodetic Data: Implications for the Deflation Mechanisms of Resurgent Calderas and Their Relationships with Seismicity
title_sort shrinking of ischia island italy from long term geodetic data implications for the deflation mechanisms of resurgent calderas and their relationships with seismicity
topic GNSS
velocity field
resurgent caldera
subsidence
earthquakes
degassing processes
url https://www.mdpi.com/2072-4292/13/22/4648
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