Publication Date:
2017-04-04
Description:
The island of Ischia, located at the northwestern end of the Gulf of Napoli (Italy), is a volcanic area that is historically active
(the Arso eruption, in 1302 and the Casamicciola earthquake, in 1883) and has diffuse hydrothermal phenomena. We present in this
work a study of the surface deformation occurring in the island, which is based on applying the Differential Synthetic Aperture
Radar Interferometry (DInSAR) algorithm referred to as Small BAseline Subset (SBAS) technique. This study is focused on the
1992–2003 time interval and SAR data acquired by the European Remote Sensing (ERS) satellites from ascending and descending
orbits have been used, thus allowing us to discriminate the vertical and east–west components of the displacements. A validation of
the DInSAR results has been carried out first by comparing the vertical deformations estimated from the SAR data with those
measured from the spirit leveling network that is present in the area. In particular, we computed the difference between the mean
vertical deformation velocities estimated from the SAR and the corresponding geodetic measurements along three main leveling
lines; the maximum value of the root mean square difference is of about 1 mm/yr. The final discussion is dedicated to the
interpretation of the detected displacements, benefiting from the overall information extracted from the ascending and descending
DInSAR measurements. In particular, DInSAR data relative to the vertical deformation component show that the present-day
subsidence of Ischia mainly develops in areas characterized by active landsliding and along faults; moreover, the deflation of the
island, which is recorded by the horizontal displacement component, is probably related to the de-pressurization of the
hydrothermal system.
Description:
Published
Description:
399-416
Description:
reserved
Keywords:
SAR interferometry
;
SBAS technique
;
leveling survey
;
hazard
;
hydrothermal systems
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
1346550 bytes
Format:
application/pdf
