Santorini Greece Earthquake Crisis - February 2025

Executive Summary:

Santorini, Greece, a major tourist destination, is experiencing a significant seismic swarm beginning in late January 2025. Thousands of earthquakes, some exceeding magnitude 5, have prompted a state of emergency, mass evacuations, and growing concerns about the upcoming tourist season. While scientists do not believe a volcanic eruption is imminent and larger earthquakes are not assured, the unusual nature of the swarm and the potential for damage are causing widespread anxiety and economic disruption. The crisis has exposed infrastructure vulnerabilities and sparked debate about investment in the island's resilience.

Key Themes and Information:

• Seismic Activity:
• A significant earthquake swarm began around January 26, 2025, with thousands of tremors affecting Santorini and nearby islands like Amorgos.
• The strongest earthquake recorded was a magnitude 5.2.
• "It's estimated that about 12,000 earthquakes with magnitudes greater than 1 have been registered in the area near Santorini and Amorgos since Jan. 26"
• The epicenter of the earthquakes appeared to be moving northward.
• The European-Mediterranean Seismological Center described the swarm as "very unusual," noting that the magnitude and rate of earthquakes have been increasing, rather than decreasing as typically expected after a large quake.
• Scientists have installed underwater seismographs to better understand the earthquake activity.
• While some small events have been recorded below Santorini, they are "pretty sparse, and they mostly predate this swarm."
• The swarm began with small earthquakes. Starting on February 1, the seismicity started to intensify, broaden, and move slightly towards the northeast.
• Focal mechanisms are largely normal-type, striking NE-SW.
• "the seismicity may be shallowing as it migrates northeastward. This kind of migration would be consistent with the movement of euids through the crust, which remains the most likely explanation for what is going on."
• "The most likely situation is that the swarm will settle down without triggering a large earthquake. However, the risk is certainly elevated above its normal level."
• "The NE-trending Ios Fault Zone appears to be a key factor in this seismic swarm. The concentration of seismicity at 10–15 km depth aligns well with the fault’s downward extension. One possible explanation is that fluids—potentially hot—are triggering seismic activity."
• State of Emergency and Response:
• A state of emergency was declared on Santorini and later Amorgos.
• "Santorini is under a state of emergency until March 3 to "address the emergency"
• Rescue teams have been deployed to Santorini.
• Schools were closed, and public events were canceled.
• Access to coastal areas and clifftop viewpoints was restricted due to landslide risks.
• The Greek government responded positively to proposals to support the existing workforce on the island and those looking to work during the season.
• Aid was expedited by the declaration of a state of emergency.
• Prime Minister Kyriakos Mitsotakis visited the island to assess the situation and urge calm.
• "We hope this phenomenon ends quickly and the island fully returns to its normal pace," Mitsotakis said.