LISBON, March 21 – In less than 48 hours, almost 1,100 minor earthquakes shook one of Portugal’s mid-Atlantic volcanic islands, leading authorities to activate an emergency plan while specialists examine what they’re calling a “seismic catastrophe.”
Since Saturday afternoon, earthquakes with magnitudes ranging from 1.9 to 3.3 have been registered on the island of Sao Jorge, according to Rui Marques, head of the Azores archipelago’s seismo-volcanic surveillance center CIVISA.
He added the majority of the tremors, which have so far caused little damage, occurred near the island’s volcanic fissure of Manadas, which erupted last in 1808.
Sao Jorge is one of the nine islands that make up the Azores and is part of the archipelago’s middle group, which also contains the prominent tourist sites of Faial and Pico, both of which are volcanic.
Luis Silveira, the mayor of the municipality of Velas, where much of Sao Jorge’s population lives, signed a document on Monday to activate an emergency plan due to the earthquakes, describing it as a precautionary measure.
Last year, earthquake swarms were observed ahead to the eruption of the Cumbre Vieja volcano on Spain’s La Palma island, around 1,400 kilometres (870 miles) southeast of the Azores.
Thousands of homes and crops were destroyed over the course of 85 days by the eruption.
CIVISA, on the other hand, has yet to determine what the series of earthquakes could mean.
“The behaviour pattern of this earthquake disaster is still unknown,” Marques told the Lusa news agency.
CIVISA has dispatched workers to the island to install two new seismic monitoring stations and measure soil gases, which are a sign of volcanic activity.
The regional Civil Protection office stated in a statement on Sunday that it had already contacted local mayors and fire departments, asking them to “stay vigilant” and assist the inhabitants of Sao Jorge if necessary.
It advised people to be calm, stay informed, and follow officials’ advice. Only 63 out of 1,100 earthquakes were felt.
The population has felt the effects of the registrations so far. Marques
“We must be concerned,” Marques told the radio station Antena 1. “We should not sound the alarm, but we will keep an eye on the situation as it develops.”