LISBON, March 21 — Authorities in Portugal’s Azores archipelago have been placed on alert after nearly 90 small earthquakes hit the mid-Atlantic volcanic island of Sao Jorge in a little over 24 hours, although there have been no reports of damage.

Sao Jorge’s Urzelina volcano last erupted in 1808 and the Azores Civil Protection authority has requested an evaluation by experts from the region’s volcanic surveillance centre.

Civil Protection said in a statement that it had already contacted local mayors and fire units, asking them to “remain vigilant” and help the people of Sao Jorge if needed.

The seismic activity began on Saturday afternoon, the authority said, urging people to stay calm, stay informed and follow the recommendations of officials.

The earthquakes ranged in magnitude from 1.9 to 3.3.

Sao Jorge, one of nine islands which make up the Azores, is home to around 8,200 people and is part of the archipelago’s central group, which includes the popular tourist destinations of Faial and Pico, both of which are also volcanic. — Reuters