Multitemporal and Multisensor InSAR Analysis for Ground Displacement Field Assessment at Ischia Volcanic Island (Italy)

Abstract

Volcanic islands are often affected by ground displacement such as slope instability, due to their peculiar morphology. This is the case of Ischia Island (Naples, Italy) dominated by the Mt. Epomeo (787 m a.s.l.), a volcano-tectonic horst located in the central portion of the island. This study aims to follow a long temporal evolution of ground deformations on the island through the interferometric analysis of satellite SAR data. Different datasets, acquired during Envisat, COSMO-SkyMed and Sentinel-1 satellite missions, are for the first time processed in order to obtain the island ground deformations during a time interval spanning 17 years, from November 2002 to December 2019. In detail, the multitemporal differential interferometry technique, named small baseline subset, is applied to produce the ground displacement maps and the associated displacement time series. The results, validated through the analysis and the comparison with a set of GPS measurements, show that the northwestern side of Mt. Epomeo is the sector of the island characterized by the highest subsidence movements (maximum vertical displacement of 218 mm) with velocities ranging from 10 to 20 mm/yr. Finally, the displacement time series allow us to correlate the measured ground deformations with the seismic swarm started with the Mw 3.9 earthquake that occurred on 21 August 2017. Such correlations highlight an acceleration of the ground, following the mainshock, characterized by a subsidence displacement rate of 0.12 mm/day that returned to pre-earthquake levels (0.03 mm/day) after 6 months from the event.

Application of modified Segment Tracing Algorithm (mSTA) Method to Identify Landslide Susceptibility Zones Around Mt. Sinabung, Indonesia

“…Methodologies for producing landslide susceptibility maps are mainly based on GIS technology. Previous published works has been explained to solve the deficiencies and difficulties in landslide susceptibility assessment [19,[21][22][23]. Practically, the procedure for preparing landslide susceptibility maps should be applicable and accurate to the field scale.…”

Surface deformation analysis in Northeast Italy by using PS-InSAR and GNSS data 

“…That approach has been successfully employed in several studies in the Himalaya-Tibet region (Grandin et al, 2012;Pezzo et al, 2012;Karimzadeh et al, 2013;Liu et al, 2018), California (Fialko, 2006;Tong et al, 2013;Chaussard et al, 2016), Anatolia (Wright et al, 2001;Walters et al, 2011;Hussain et al, 2016;Weiss et al, 2020), and in Italy (Cheloni et al, 2014;Pezzo et al, 2015Pezzo et al, , 2020bSerpelloni et al, 2016;Anderlini et al, 2020). Other studies can also be mentioned related to the other natural and anthropogenic phenomena, such as subsidence (Teatini et al, 2005;Tosi et al, 2010Tosi et al, , 2013Osmanoǧlu et al, 2011;Da Lio and Tosi, 2018;Del Soldato et al, 2018;Polcari et al, 2018;Farolfi et al, 2019aFarolfi et al, , 2019bFloris et al, 2019), landslides and slope instabilities (Žibret et al, 2012;Komac et al, 2015;Notti et al, 2015;Aslan et al, 2020), sinkholes (Busetti et al, 2020), volcanic processes Pezzo et al, 2020a;Beccaro et al, 2021), monitoring of infrastructures, reservoirs and mining activities (Perski et al 2009;Klemm et al, 2010;Ab Latip et al, 2015;Gama et al, 2020).…”

Ground displacement assessment on Pico Volcano, Azores, by multitemporal InSAR data

“…The stack of SAR images, on both ascending and descending orbits, has been processed with the small baseline subset (SBAS) method 5 , 6 . Although this method is robust and reliable, especially in areas where the loss of InSAR phase coherence is present, 7 the atmospheric delay strongly affects the interpretation of ground motion 8 . Therefore, customized settings and processing approaches are needed for mitigating these undesired effects.…”