Publication Date:
2022-01-03
Description:
We analyse spatiotemporal gravity changes observed on the Ischia island
(Italy) accompanying the destructive earthquake of 21 August 2017. The 29 May 2016 to
22 September 2017 time-lapse gravity changes observed at 18 benchmarks of the Ischia
gravimetric network are rst corrected for the gravitational e ect of the surface deforma-
tion using the deformation-induced topographic e ect (DITE) correction. The co-seismic
DITE is computed by Newtonian volumetric integration using the Toposk software, a
high-resolution LiDAR DEM and the co-seismic vertical displacement eld derived from
Sentinel-1 InSAR data. We compare numerically the DITE eld with its commonly used
Bouguer approximation over the island of Ischia with the outcome that the Bouguer ap-
proximation of DITE is adequate and accurate in this case. The residual gravity changes
are then computed at gravity benchmarks by correcting the observed gravity changes
for the planar Bouguer e ect of the elevation changes at benchmarks over the same pe-
riod. The residual gravity changes are then inverted using an inversion approach based
on model exploration and growing source bodies, making use of the Growth-dg inversion
tool. The found inversion model, given as subsurface time-lapse density changes, is then
interpreted as mainly due to a co-seismic or post-seismic disturbance of the hydrothermal
system of the island. Pros and weak points of such interpretation are discussed.
Description:
Slovak Research and Development Agency under the contracts (project) No. APVV-16-0482 (acronym LITHORES) and No. APVV-19-0150 (acronym ALCABA) and by the VEGA grant agency under projects No. 2/0006/19 and 2/0100/20.
Spanish Ministerio de Ciencia, Innovacion and Universidades research project DEEP-MAPS (RTI2018-093874-B-I00).
Description:
Published
Description:
345–371
Description:
4V. Processi pre-eruttivi
Description:
JCR Journal
Keywords:
Volcano Geodesy
;
4D gravimetry
;
co- seismic time-lapse gravity change,
;
Growth inversion
;
04.03. Geodesy
;
04.08. Volcanology
;
05.06. Methods
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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