The opulent mid-Atlantic volcanic island of Sao Jorge, Portugal, has been rattled by more than 14,000 minor earthquakes in the last week alone.

Fatima Viveiros, a volcanologist who works for the region's CIVISA seismo-volcanic surveillance center and who has lived in the Azores islands, fears that the earthquakes could trigger a volcano for the first time since1808.

The quakes have reached magnitudes of 3.3 on the Richter scale.

Viveiros and other experts were carrying yellow machines on their backs to measure soil gases on Sao Jorge.

Soil gases like carbon dioxide and sulfur are markers of volcanic activity, and Viveiros and her colleagues have been digging for answers for days, braving Sao Jorge's rain and high winds. So far, the levels have remained stable.

The abrupt rise in seismic activity on the island is reminiscent of tremors seen before the eruption of the Cumbre Vieja volcano on Spain's La Palma island last year, around 1,400 km (870 miles) southeast of the Azores.

Viveiros, who went to La Palma to aid the Canary Islands Volcanology Institute and monitor soil gases there, described that the scenario is "something similar to what happened in La Palma."

The volcano alert was raised to a level 4 on Wednesday by CIVISA, meaning that there was a "real possibility" it could erupt.

The president of the Azores, a Portuguese autonomous area, Jose Bolieiro, said the number of earthquakes that impacted Sao Jorge in recent days was double what was reported in the region as a whole last year.

Bolieiro told reporters that "there is clearly an abnormality."

In recent days, many residents have left the island by air or sea.

Portugal's President Marcelo Rebelo de Sousa arrived by helicopter in Sao Jorge on Sunday to receive a briefing regarding the situation and to reassure the local populace. He also went to see an ancient tower that had survived the 1808 eruption.

Dozens of troops have been sent to Sao Jorge, where they are staying in big tents with mattresses large enough to accommodate 100 people in case of an evacuation. Municipalities in Sao Jorge have also converted several structures into temporary response centers.

An official told Reuters that extra resources will be dispatched to the island next week.