Earthquake swarm near Santorini volcano prompts emergency meeting, Greece
A series of more than 130 earthquakes, reaching up to M3.0, has been detected near the Santorini summit since January 28, 2025, prompting an emergency government meeting by the Permanent Scientific Monitoring Committee to assess potential volcanic risks.
Seismic swarm in the Dodecanese Islands, Greece, on January 30, 2025. Image credit: TW/SAM, Google
Greek authorities convened an emergency meeting by the Permanent Scientific Monitoring Committee on January 29 after increased seismic activity was detected in the Santorini summit along the central Kameni fault in the northern part of the volcanic system.
More than 130 earthquakes, the strongest reaching M3.0, have been recorded northeast of Santorini since January 28. Scientists are analyzing the data to determine whether the activity is related to magma movement or regional tectonics.
“Based on available data, scientists see no cause for immediate concern,” the Greek Ministry of Climate Crisis and Civil Protection stated.
Population estimates indicate that 5 176 people live within 5 km (3.1 miles) of the volcano, 12 266 within 10 km (6.2 miles), and 67 468 within 100 km (62.1 miles), showing the importance of continued monitoring and preparedness measures.
According to the Permanent Scientific Monitoring Committee of the Greek Volcanic Arc, the earthquakes are concentrated approximately 25 km (15.5 miles) northeast of Santorini, with depths ranging from 25 km to 5 km (15.5 miles to 3.1 miles). The earthquakes were strongest in northern Santorini, mainly in Oia.
The swarm’s location suggests the potential involvement of the Kolumbos submarine volcano, located just 6.5 km (4 miles) northeast of Santorini. Kolumbo is part of the larger Santorini volcanic complex and is known for its major eruption in 1650, which caused significant damage and fatalities due to pyroclastic flows, tsunamis, and gas emissions.
The volcano remains active, with hydrothermal activity and periodic seismic swarms, making it a key focus for monitoring in the region. Investigations are underway to determine whether the seismicity is caused by tectonic stress along the Kolumbos and Kameni fault systems or deeper magmatic processes.
Experts suggest the current situation warrants close observation. While no surface changes have been detected, real-time geophysical monitoring will help determine whether magma is accumulating at depth.
The emergency meeting, chaired by Vasilis Kikilias, the Minister of Climate Crisis and Civil Protection, included key government officials, scientists, and emergency responders. Among the attendees were Christos Triantopoulos, Deputy Minister of Natural Disaster Rehabilitation, Vasilios Papageorgiou, Secretary General of Civil Protection, Nikolaos Zorzos, Mayor of Thira, and geoscientists from the Geodynamic Institute and the Institute for the Study and Monitoring of the Santorini Volcano (ISMOSAV).
Discussions focused on updating emergency plans and ensuring Santorini’s civil protection mechanism is prepared.
“The aim is to better prepare the civil protection mechanism in Santorini, taking into account the special geological, geomorphological, and socio-economic characteristics of the island,” officials stated.
The government has activated monitoring protocols by recalling similarities to the 2011 – 2012 volcanic crisis that lasted 14 months but did not result in an eruption.
During the 2011 to 2012 event, a shallow magma intrusion beneath the Santorini summit caused widespread seismicity, increased degassing at Nea and Palea Kameni hot springs, and a 12 cm (4.7 inches) horizontal expansion of the caldera. The episode did not lead to an eruption but prompted authorities to strengthen monitoring networks and emergency response plans.
Seismologists and volcanologists are continuously assessing data from GPS stations, thermal imaging, gas emissions, and seismic records. The Ministry of Climate Crisis and Civil Protection maintains that, at present, no immediate risk exists but advises residents and tourists to remain informed through official sources.
Santorini, part of the Hellenic Volcanic Arc, is a complex volcanic structure composed of overlapping shield volcanoes cut by multiple calderas. The caldera rim rises to an elevation of 367 m (1 204 feet) and encircles an active volcanic island in the center of the bay.
The island has a long history of volcanic activity, with major eruptions occurring over the past 400 000 years. The youngest caldera was formed approximately 3 600 years ago during the Minoan eruption, one of the most important volcanic events in human history. Post-Minoan activity has resulted in the formation of lava domes including those on Nea Kameni and Palea Kameni.
Santorini’s last confirmed eruption took place in 1950, producing a small lava dome and explosive activity. Previous eruptions occurred from 1939 to 1941, 1928, 1925 to 1926, and 1866 to 1870, with volcanic explosivity indices (VEI) of 2 to 4. The most powerful recorded eruption, estimated at VEI 7, occurred around 1610 BCE.
The region’s volcanic activity is driven by the subduction of the African Plate beneath the Eurasian Plate, with the island sitting on continental crust over 25 km (15.5 miles) thick. Kolumbos, an active submarine volcano located 6.5 km (4 miles) northeast of Santorini, remains an important area of study for potential underwater eruptions.
Updates
February 3
Authorities have closed schools in Santorini, Anafi, Ios, and Amorgos on February 3.
Residents have been advised to avoid structurally weak buildings, large indoor gatherings, and high-risk areas such as ports and steep slopes. They have also been urged to drain swimming pools to reduce the risk of structural damage from water movement.
References:
1 Santorini – GVP – Accessed on January 30, 2025
2 Greek Authorities Monitor Mild Seismic Activity in Santorini – GREEK CITY TIMES – January 30, 2025
3 Greece Monitors Santorini Volcano After Increase in Seismic Activity – iefimerida – January 30, 2025
4 Experts meet to discuss seismic activity at Santorini volcano – ekathimerini-com – January 30, 2025
5 Santorini volcano (Greece): earthquake swarm, possibly related to volcanic activity/Tom Pfeiffer – VOLCANO DISCOVERY – January 30, 2025
6 Santorini: The island is experiencing seismic and volcanic activity – Emergency meeting – D news – January 29, 2025
Rishika holds a Master’s in International Studies from Stella Maris College, Chennai, India, where she earned a gold medal, and an MCA from the University of Mysore, Karnataka, India. Previously, she served as a Research Assistant at the National Institute of Advanced Studies, Indian Institute of Science, Bengaluru, India. During her tenure, she contributed as a Junior Writer for Europe Monitor on the Global Politics website and as an Assistant Editor for The World This Week. Her work has also been published in The Hindu newspaper, showing her expertise in global affairs. Rishika is also a recipient of the Women Empowerment Award at the district level in Haryana, India, in 2022.
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