A bell tower of an Orthodox church in the town of Oia on the earthquake-truck island of Santorini, Greece, is visible as the main town of Fira is lit by the sun in the background, February 4, 2025.
| Photo Credit: AP
An earthquake swarm occurs when multiple seismic events of comparable intensity strike a small area in relatively quick succession.
A state of emergency has been declared on Greece’s Santorini and the nearby islands of Ios, Amorgos, and Anafi after a swarm of undersea earthquakes this month, sometimes every few minutes, prompted thousands of people to move to the mainland.
Greece’s chief seismologist has said the frequency of earthquakes affecting the area has eased in recent days, but that the outlook for continued tremors in the coming weeks remains uncertain.
“Unfortunately, for now, we must wait,” seismologist Costas Papazachos told state-run ERT radio on February 17.
Papazachos, a professor of geophysics at the University of Thessaloniki, is currently as the representative of two emergency committees that include scientists and officials from government, the military, and emergency services. He said Santorini, a volcanic island shaped by catastrophic eruptions, didn’t face danger from its dormant volcano but noted that magma was affecting the tremors.
“The root cause of the activity is the interaction of tectonic and magmatic processes,” he said. “That does not mean that the molten material will manage to break through 8 km of crust and cause a new volcanic eruption.”
Swarms have been reported in peninsular India. After heavy rain, water seeps into small fractures in underground rocks. A 2008 study estimated that for every 10 metre’s rise in the water table, the pressure inside the rocks increased by almost 1 atm, and which is released in earthquake swarms.
With inputs from agencies
Published – February 18, 2025 10:11 am IST
