What’s an earthquake swarm?

A bell tower of an Orthodox church within the city of Oia on the earthquake-truck island of Santorini, Greece, is seen as the primary city of Fira is lit by the solar within the background, February 4, 2025.
| Photograph Credit score: AP

An earthquake swarm happens when a number of seismic occasions of comparable depth strike a small space in comparatively fast succession.

A state of emergency has been declared on Greece’s Santorini and the close by islands of Ios, Amorgos, and Anafi after a swarm of undersea earthquakes this month, generally each jiffy, prompted 1000’s of individuals to maneuver to the mainland.

Greece’s chief seismologist has mentioned the frequency of earthquakes affecting the realm has eased in current days, however that the outlook for continued tremors within the coming weeks stays unsure.

“Sadly, for now, we should wait,” seismologist Costas Papazachos advised state-run ERT radio on February 17.

Papazachos, a professor of geophysics on the College of Thessaloniki, is at the moment because the consultant of two emergency committees that embody scientists and officers from authorities, the navy, and emergency providers. He mentioned Santorini, a volcanic island formed by catastrophic eruptions, didn’t face hazard from its dormant volcano however famous that magma was affecting the tremors.

“The foundation explanation for the exercise is the interplay of tectonic and magmatic processes,” he mentioned. “That doesn’t imply that the molten materials will handle to interrupt via 8 km of crust and trigger a brand new volcanic eruption.”

Swarms have been reported in peninsular India. After heavy rain, water seeps into small fractures in underground rocks. A 2008 examine estimated that for each 10 metre’s rise within the water desk, the strain contained in the rocks elevated by virtually 1 atm, and which is launched in earthquake swarms.

With inputs from businesses