As earthquakes rattle Santorini, Amorgos, Ios, and nearby islands, seismologists are closely monitoring the situation, assessing whether a larger tremor looms ahead. Gerasimos Papadopoulos, a seismologist at the Hellenic Mediterranean University, warns that a stronger earthquake is likely but dismisses the possibility of a catastrophic event like the 1956 Amorgos quake.

Speaking to Greek Mega TV, Papadopoulos describes the recent seismic activity as “intensely evolving, especially over the past weekend.” He points to key indicators suggesting that “for at least the past 48 hours, we have been in a clear foreshock sequence.”

What Are Foreshocks?

A seismic sequence typically consists of three stages:

  • Foreshocks – smaller tremors that precede a major earthquake.
  • Mainshock – the largest quake in the sequence.
  • Aftershocks – follow-up tremors as the Earth’s crust adjusts.

Foreshocks can strike minutes, days, or even months before the mainshock. However, scientists can only confirm them after a larger earthquake occurs. By analyzing seismic patterns, experts determine whether ongoing tremors signal a major event—or just random activity.

Shifting Epicenters Raise Concerns

Papadopoulos notes that earthquake epicenters are migrating. Initially concentrated around Santorini and the underwater Kolumbo volcano, they are now shifting northeast, running roughly parallel to Amorgos’ coastline.

The Amorgos Fault, responsible for the recent quakes, has extended its activation zone to 30 km, according to the seismologist. He clarifies that this is only a portion of the fault, known as the Amorgos fault, that ruptured in 1956, causing Greece’s most powerful earthquake in the last century at 7.7 magnitude.

How Long Will This Last?

Papadopoulos warns that the foreshock sequence could persist for months. He draws a comparison to the 2021 Arkalochori earthquake, where a 6.0-magnitude tremor struck on September 27 after nearly four months of foreshocks.

While a major quake isn’t guaranteed, the evolving seismic activity suggests that residents and authorities should remain on high alert.