Earthquakes in the wider Santorini region appear endless, leaving the scientific community deeply concerned about the ongoing cycle of seismic activity. Santorini: The ultimate eruption nightmare?
Indeed, scientists are now openly discussing the possibility of an earthquake exceeding 6 on the Richter scale, and even the scenario of triggering the volcano. Meanwhile, tremors continue, with seismographs recording quakes of up to 5 on the Richter scale during the night.
Akis Tselentis: Volcano activation is feasible – What is the worst-case scenario?
“In the early days, when it was believed that earthquakes were not 100% linked to volcanic activity (I refer to Kolumbo), I explained that there is a two-way relationship between faults and rising magma. In answer to whether we could experience a 6R earthquake, I said yes,” stated seismology professor Akis Tselentis in a recent post.
He added, “The worst-case scenario would be the activation of the major fault in Amorgos direction of ND BA – an event that, according to my calculations and the observed seismic trends (Coulomb stress for the experts), appears negligible. However, the scenario of its activation is feasible and, in that case, would result in a significantly large earthquake. Both scenarios would trigger a tsunami.”
Kostas Synolakis: A volcanic eruption is possible, but not a major one
Professor of Natural Disasters Kostas Synolakis, speaking on ANT1, referred to indicators suggesting a volcanic eruption in the area is likely. “Some measurements from Kolumbo indicate that some gases from the seafloor may have changed, and there is evidence of a cluster of earthquakes focused around a specific area, Anydro (…).”
He continued, “Since summer, there has been deformation in the ground around Kalanderas. In Kolumbo, gases also emerge from the seabed. These, combined with seismic tremors and the movement of volcanic fluids to the surface, make a volcanic eruption possible—though not one of great magnitude.”
Kostas Papazachos: The worst-case scenario
Speaking on Action 24, seismology professor Kostas Papazachos, President of the Institute for the Study and Monitoring of the Santorini Volcano (IMBIS), emphasised, “We are not heading towards an explosive release with Santorini’s earthquakes.”
He noted, “There could be a worst-case scenario beyond 6R.”
Papazachos explained, “Even if the main segment of the fault breaks, Santorini, Ios, Anafi, and Amorgos would suffer only limited impacts in all models. We are not all sure that the upper limit is 6R, as the zone has expanded considerably. At present, a worse scenario might be possible,” though he estimated that even a 6.5R quake would be manageable.
He added, “Assuming a worst-case scenario of a 6.5 earthquake, we have run the models, calculated the figures, and observed the movements of neighbouring islands. I can assure you that, generally, the ground motions are limited. Properly constructed, earthquake-resistant buildings would cope without issue. Moreover, inspections to date have shown buildings have performed very well.”
“Of course, a strong earthquake would have consequences. I remind you of the 7.0 in Samos, 6.3 in Tyrnavos in 2021, and 6.0 in Arkalochori, and we know that significant damage occurred near the fault zone. Here, the fault lies in Anydro, 25 kilometres away—a distance that helps mitigate the impacts.”
Gerassimos Papadopoulos: Why we do not want a 6R earthquake
“Based on current official statements from seismic and volcanic risk committees, no upper limit beyond 6R is mentioned. A much larger earthquake would not be beneficial; while it might relieve pressure, it could also be harmful,” said seismologist Gerassimos Papadopoulos.
“I cannot accept the logic that a 6R quake would trigger a release. Then other issues arise. A 6R quake can trigger further fault activation, and that is taken into account.”
Manolis Skordilis: The most likely scenario is No 6R earthquake
“For me, it is most likely that a 6R earthquake will not occur,” estimated seismologist Manolis Skordilis.
He noted, “If we add up the energy of the tremors in the region, it’s equivalent to a 6.1R earthquake.”
Vasilis Karastathis: Seismic clusters persist over time
“Usually, clusters of earthquakes persist for long periods,” explained Vasilis Karastathis, Director of the Hellenic Institute of Geodynamics in Athens.
“We have not ruled out the possibility of a larger earthquake. We must ensure that seismic activity remains confined to this fault.”
Endless earthquakes
Seismic activity continues unabated in the Santorini region and surrounding islands, intensifying anxiety among residents and experts. Between 10:29 and 11:20, eight earthquakes of over 4R were recorded.
Specifically, at 10:29 on Wednesday morning, a 4.9R quake was recorded south-west of Arkesini in Amorgos, with an epicentre 27 kilometres to the south-west and a depth of 16 kilometres, according to the Geodynamics Institute.
Seismic activity persisted throughout the night in the Cyclades maritime area, with the strongest tremor—a 5R quake—recorded at 3:14, approximately 24 kilometres south-southeast of the Arkesini community in Amorgos. Dozens of quakes were recorded during the night, and twenty minutes after the 5R event, another 4R quake was recorded with the same epicentre
