The 2021 unrest phase of Vulcano volcano (Aeolian islands) detected by SAR,GNSS and GB-RAR

Starting from July 2021, a gradual unrest of Vulcano volcano was recorded by monitoring system managed by INGV, marked by a progressive change of many parameters from the multi-disciplinary networks.

The fumaroles located on the crater rim and along the flank of the cone shown temperature increase ( up to 350 degree Celsius) and  an increase of the flux of carbon dioxide and sulfur dioxide in gas emissions. Furthermore, the increase of the occurrence of with very-long-period (VLP) events was recorded by seismic network, and a rapid uplift of about 1 cm/month was recorded at VCRA GNSS permanent station located on the North slope of the “La Fossa” cone.

In order to image the ground deformation accompanying the unrest phase, we analyzed the 2020-2021 ascending and descending ESA-Copernicus Sentinel-1A and 1B C-band SAR (Synthetic Aperture Radar) acquired in TopSAR (Terrain Observation with Progressive Scans SAR) Interferometric Wide mode with A-DINSAR techniques. On October 2021 a new GNSS survey was performed on the ”Lipari-Vulcano” network. We integrated the SAR data and the GNSS data applying the SISTEM method, and the preliminary results are consistent with the Vulcano hydrothermal system dynamics, with a deformation pattern limited to the cone area.

In order to monitoring continuously and more in detail the change in ground deformation, on December 2021 we installed 4 additional GNSS mobile stations and a permanent GB-RAR (ground-based real aperture radar) on the island. The GB-RAR system was installed at the Lipari Observatory, at a distance of about 5 km from Vulcano, and it is able to image the whole Vulcano north area, with a rectangular pixel resolution of 3x30 m and a precision of the displacement along the line of sight of about 1 mm.

At time of this abstract no ground deformation have been recorded in the last month, the microseismic activity reduced but the fumarole temperatures at the crater and gas emissions of carbon and sulphur dioxide remained at high level.