Present‐Day Surface Deformation of Sicily Derived From Sentinel‐1 InSAR Time‐Series. Issue 3 (20th March 2022)

• Record Type: Journal Article
• Authors: Henriquet, Maxime; Peyret, Michel; Dominguez, Stéphane; Barreca, Giovanni; Monaco, Carmelo; Mazzotti, Stéphane
• Is Part Of: Journal of geophysical research. Volume 127:Issue 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-20
• Subjects: PS‐InSAR -- Sentinel‐1 -- GNSS -- mean surface velocity field -- tectonics -- Sicily; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1029/2021JB023071
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: The Quaternary geodynamics of the Central Mediterranean region is controlled by the migration of narrow orogenic belts within the slow Nubia‐Eurasia plate convergence. As testified by the occurrence of major volcanic and seismic events, the Eastern Sicilian Margin is presently one of the most active regions. Using a Permanent‐Scatterer approach, we process Sentinel‐1 satellite images acquired from 2015 to 2020 to provide an island‐wide quantification of surface displacements at a high spatiotemporal resolution. We then convert the calculated mean surface velocities along the ascending and descending satellite line of sight into the ITRF2014 reference frame by using GNSS velocity data derived from regional stations. The resulting pseudo‐3D velocity field mainly highlights a general uplift of about 1.5 ± 0.5 mm/yr of the Nebrodi‐Peloritani range and its differential motion with respect to mainland Sicily along the Cefalù‐Etna seismic zone. Permanent/Persistent‐Scatterer (PS) vertical velocities in the Eastern Hyblean region reveal a long wavelength eastward downbending of the margin, including the inferred epicentral area of the 1693 Noto earthquake. Compared to Quaternary coastal uplift rates, these results confirm the relative low activity of Western Sicily, a potential slow uplift of South‐Central Sicily and a significant discrepancy along the Eastern Hyblean margin were PS‐derived vertical velocities that appear 2–3 mm/yr lower than the Quaternary rates. Over the 2015–2020 timespan, transient processes are also captured, notably on Mount Etna, showing both magmatic pressurization uplift and collapse of the eastern flank, but also all over Sicily where numerous gravitational mass movements and anthropogenic ground subsidence are detected. Plain Language Summary: The recent geodynamics of Central Mediterranean is controlled by the migration of narrow orogenic belts within the slow Nubia‐Eurasia plate convergence. As testified by major volcanic and seismic events, the Eastern Sicilian Margin is a region of strong tectonic activity. Using a Permanent‐Scatterer approach, we process Sentinel‐1 data to provide an island‐wide quantification of surface displacements from 2015 to 2020. We convert the calculated mean surface velocities along the satellite line of sight into the ITRF2014 reference frame using GNSS data. The resulting velocity fields highlight a general uplift of the Nebrodi‐Peloritani range and its differential motion relative to mainland Sicily along the Cefalù‐Etna seismic zone. Permanent/Persistent‐Scatterer (PS) vertical velocities in the Eastern Hyblean region reveal a long wavelength eastward downbending of the margin including the inferred epicentral area of the 1693 Noto earthquake. These results are compared to Quaternary coastal uplift rates, confirming the relative low activity of Western Sicily, a potential slow uplift of South‐Central Sicily, and a significant discrepancy along the Eastern Hyblean margin where PS vertical velocities are lower than the Quaternary rates. Transient processes are also captured, notably on the Etna volcano, but also all over Sicily where numerous landslides or anthropogenic ground subsidence are captured. Key Points: Processing Sentinel‐1 data from 2015 to 2020 provide the first large‐scale surface velocity field of Sicily at a high spatial resolution The estimated low deformation rates in Sicily result from the complex interplay between permanent and transient processes The most striking tectonic features concerns the Cefalù‐Etna seismic zone, Mount Etna dynamics and the eastern coast of the Hyblean Plateau