The role and impact of medicanes on coastal boulder dynamics: a preliminary case-study from the Maltese Islands.

Extreme meteorological events, such as medicanes, are increasingly recognized as key drivers of geomorphic transformation along rocky coastlines. This study explores the response of coastal boulder deposits in Malta to Medicane Helios, focusing on detachment, displacement, and the role of localized geomorphic vulnerabilities.

Medicane Helios, originating over the North African coast, intensified as it traversed the central Mediterranean, reaching Malta on February 9–10, 2023. Its passage was marked by torrential rainfall, gale-force winds, and intense wave energy that reshaped the coastal landscape. While studies often generalize the effects of such storms, this research emphasizes micro-scale interactions between wave energy and specific geomorphic features, including solution hollows and structural joints.

Field observations and aerial surveys using unmanned aerial vehicles (UAVs) were conducted pre- and post-event, providing data for 3D terrain models. The analysis revealed significant movement of boulders, including rotational displacement and intertidal reconfiguration, previously unreported during other extreme events in the region. The findings highlight not just the physical redistribution of clasts but also newly exposed erosional features, such as abrasion marks and scree accumulations.

By drawing parallels with other medicanes, the study underscores the increasing vulnerability of Mediterranean coastal zones to intensified storm impacts. These results emphasize the necessity of integrating localized geomorphic assessments with broader climate models to develop effective coastal defence strategies. The outcomes have broader implications for understanding the resilience of coastal systems to future climatic stressors.