Overview

• A large section of the caldera cliff gave way at 15:30 local time (12:30 UTC) on August 20, sending debris into the sea and a dense dust cloud over Imerovigli.
• Resident video shows the plume spreading across the cliff-top settlement and nearby tourist areas.
• Geologists highlight the inherent instability of Santorini’s volcanic slopes, and local reports indicate recent construction added load at the collapse site.
• The incident follows an intense seismic swarm earlier in 2025 with more than 20,000 tremors recorded between January 26 and February 22, which experts attributed to tectonic movements.
• Earlier this year, the government allocated £2.5 million for an emergency evacuation route, and local authorities imposed measures including a construction ban, pool-draining advisories and restricted access to Athinio port.