The increased seismic activity in the Santorini region over the past few hours has led to the implementation of precautionary civil protection measures.

The decision was made following an assessment by the Seismic Risk Committee, after successive tremors in the sea area between Santorini and Amorgos, including two strong earthquakes measuring 4.3 and 4.1 on the Richter scale, recorded on Saturday afternoon off the coast of Anafi.

The President of the Earthquake Planning and Protection Organization (OASP), Professor Efthymios Lekkas, urgently convened a joint meeting of the Permanent Scientific Committee for Seismic Risk Assessment and the Permanent Scientific Committee for Monitoring the Greek Volcanic Arc. The objective was to assess the seismic activity and decide on possible precautionary measures.

The Committee recommended closing schools in Santorini and avoiding large gatherings in enclosed spaces. Additionally, citizens were advised to avoid access to and staying at Ammoudi and Old Port of Fira, to ensure their safety in case of a stronger earthquake.

Following this, the Municipality of Thira announced the implementation of these measures, urging residents to remain cautious and follow the authorities’ instructions. Scientists continue to monitor seismic activity to determine if further actions may be necessary.

Official Announcement Following the Emergency Meeting:

“Due to the seismic activity over the past 48 hours in the sea area between the islands of Thira and Amorgos, the President of OASP, Professor Efthymios Lekkas, convened a joint meeting today of the two committees (the Permanent Scientific Committee for Seismic Risk Assessment and Reduction and the Permanent Scientific Committee for Monitoring the Greek Volcanic Arc of OASP).”

The meeting was held at the Ministry of Climate Crisis and Civil Protection, in the presence of Minister Vassilis Kikilias, Deputy Minister Evangelos Tournas, the Secretary General of Civil Protection Vassilis Papageorgiou, as well as the leadership of the Fire Service.

After a thorough review of all available data, it was unanimously agreed by all committee members that:

1. Seismic activity within the caldera has subsided.
2. Increased seismic sequences have been recorded over the past 24 hours in the Anyhdros area, between Thira and Amorgos, with a maximum magnitude of 4.3. This activity is not related to volcanic activity, as it is caused by underwater faults along a northeast-southwest axis.

The committees recommended the following precautionary measures:

• Schools will remain closed on Monday, February 3, 2025.
• Citizens should avoid large gatherings in enclosed spaces.
• Avoidance of access and staying at Ammoudi and Old Port of Fira.

If deemed necessary, another follow-up meeting will be scheduled.

Regarding public earthquake safety guidelines, information can be found on the official websites of the Earthquake Planning and Protection Organization (www.oasp.gr) and the Ministry of Climate Crisis and Civil Protection.

Announcement by the Municipality of Thira

Shortly after, the Municipality of Thira issued an official announcement regarding the implementation of precautionary civil protection measures due to the ongoing seismic activity in the region.

The statement reads:

Subject: “Implementation of precautionary civil protection measures due to the ongoing seismic activity in the Thira region.”

Decision No. 27/2025 by the Deputy Mayor of Thira

Taking into account:

1. Article 58, paragraph 1 of Law 3852/2010 (Government Gazette 87/A/2010)
2. Article 75, paragraph I, section z of Law 3463/2006 (Government Gazette 114 A/8.6.2006) “Ratification of the Municipal and Community Code,” which states that municipalities are responsible for coordinating and overseeing civil protection measures to prevent, prepare for, respond to, and recover from disasters within their jurisdiction
3. Decision No. 8/09.01.2024 by the Mayor of Thira regarding “Appointment of Deputy Mayors of Thira, from 09.01.2024 to 30.06.2026”
4. Urgent document No. 56/01.2.25 from the General Secretariat of Civil Protection of the Ministry of Climate Crisis and Civil Protection, titled: “Implementation of precautionary civil protection measures due to the ongoing seismic activity in the Thira region.”

It is decided:

A. The suspension of operations for all educational institutions in the Municipality of Thira (kindergartens, primary, and secondary schools) on Monday, February 3, 2025.

B. The cancellation of scheduled events and gatherings in enclosed spaces within the Municipality of Thira on Sunday, February 2, 2025, and Monday, February 3, 2025.

C. Avoiding access and staying at Ammoudi and the Old Port of Fira, as precautionary civil protection measures due to the ongoing seismic activity in the Thira region.

Intense Seismic Activity in the Greater Santorini Area

It is worth noting that seismic activity has been intense in the sea area around Santorini and its neighboring islands over the past few hours, with dozens of minor earthquakes recorded.

The most recent earthquake occurred at 15:29 on Saturday, measuring 4.4 on the Richter scale. The tremor was 35.2 km east-northeast of Thira, with a focal depth of 2 km.

Earlier, the Geodynamic Institute of the National Observatory of Athens reported that at 14:51, a 4.0-magnitude earthquake was recorded 22 km northeast of Thira, with a focal depth of 5 km.

The aftershock activity in the region remains intense, with minor tremors ranging between 2-3 on the Richter scale.

Earthquake Swarm in the Cyclades

The aftershock activity has remained intense, with minor tremors recorded between 2-3 on the Richter scale. A 3.1-magnitude earthquake was also reported 18 km south-southeast of Arkesini, Amorgos.

On Saturday morning, a series of minor earthquakes occurred within minutes of each other in Amorgos and Santorini.

Seismologist Gerasimos Papadopoulos on the Surge of Earthquakes in Santorini and Amorgos: “The Greater the Magnitude, the Higher the Risk”

Renowned seismologist Gerasimos Papadopoulos commented on the series of tremors affecting Santorini, Amorgos, and the surrounding smaller islands. Among other things, he stated:

“As magnitudes increase, so does the seismic risk.”

Statement by Gerasimos Papadopoulos

“Seismic surge in Santorini-Amorgos. Another increase in magnitudes, with a recent 4.1 quake. The larger the magnitudes, the greater the seismic risk. The fault mechanism published by the Geodynamic Institute confirms that these earthquakes are tectonic, not volcanic.”