The Greek island of Santorini have been told to close on Monday in response to an increase in seismic activity in recent days.
Authorities have also advised against “large gatherings in enclosed spaces” across the island – a popular tourist destination known for its whitewashed buildings and blue domed churches.
Tremors of up to 4.9 in magnitude were recorded north-east of the island on Monday, while recent days have seen quakes of 4.3 and 3.9 magnitude reported nearby.
Santorini is on what is known as the Hellenic Volcanic Arc – a chain of volcanic islands created by plate tectonics – but the last major eruption was in the 1950s.
A volcanic earthquake occurs when volcanic eruptions move magma and fluids towards the Earth’s surface, this in turn leads to the movement of tectonic plates, which can be felt on the surface as earthquakes or tremors.
Greek authorities said that the recent minor earthquakes were related to tectonic plate movements instead of volcanic activity, and that activity in the Santorini caldera – the volcanic basin the island sits around – remains in decline.
The tremors recorded by geologists are considered minor or light, but authorities have recommended a number of preventative measures in addition to the school closures, including asking ships to avoid the ports of Ammoudi and Fira.
Big cruise ships often anchor near the Old Port of Fira, with passengers being brought to shore on smaller boats.
Schools were also told to close on the nearby islands of Anafi, Ios and Amorgos.
More than 200 earthquakes were recorded across Greek islands in the past 48 hours, according to the University of Athens’ Seismological Laboratory.
On Sunday, Prime Minister Kyriakos Mitostakis chaired an emergency meeting at Maximos Palace with the head of Greece’s earthquake planning and protection organisation (OSAP), Efthimios Lekkas, and the minister of civil protection, Vassilis Kikilias.
Following the meeting to discuss the continuous earthquakes in the area between Santorini and Amorgos, Kikilias said the government remains alert and asked the people in affected islands to follow instructions issued by the authorities.
People were advised to avoid abandoned buildings and travelling on routes where landslides are likely to occur.
While the recent tremors are thought to be unlikely to be a precursor to an eruption, the possibility of a stronger eruption cannot be ruled out.
Kostas Papazachos, a professor of geophysics at Thessaloniki Aristotle University, told public broadcaster ERT that the precautionary measures were “precisely to limit the impact of a stronger earthquake”. —BBC
