The Impact of Medicane Surge on the Vertical Land Motion of South Sicily Coast, Italy

Abstract. Vertical land movement is a dynamic phenomenon along the Mediterranean coast, influenced by natural and anthropogenic factors. One natural factor affecting coastal stability is storm-induced wave inundation. Annual storms are common in the Mediterranean, particularly in autumn, and include the Medicane storms, characterized by significant wave heights and occurring nearly once a year. Sicily, Italy, is frequently impacted by both annual and Medicane storms. This study investigates the impact of Medicane storms on vertical land movement along Sicily's southern coast. Using Sentinel-1 images (2015–2021) and interferometric TOPSAR analysis with SNAP 8.0, this research compares medium-term vertical land movement (2015–2020), annual vertical motion (2020–2021), and vertical displacement before and after Medicane Zorbas (September 2018) and Medicane Apollo (October 2021). Results show that medium-term and annual vertical motion and post-Medicane Zorbas dynamics predominantly indicate uplift. However, after Medicane Apollo, significant subsidence (0.005 m to 0.058 m) was observed along the southern Sicilian coast. The findings highlight that storm-induced flooding from Medicane events influences coastal subsidence. Differences in vertical land motion dynamics between Medicane Zorbas and Medicane Apollo are attributed to their distinct storm paths. Medicane Apollo crossed Sicily, moving from North Africa to Europe, causing direct impact, while Medicane Zorbas turned towards the Ionian Sea, sparing Sicily from direct effects. This study highlights the critical role of storm paths in shaping coastal land dynamics and informs coastal management strategies in Mediterranean regions.