(ORDO NEWS) — Scientists have reported a high probability of a volcanic eruption. But when, where and whether it will actually happen, experts are currently trying to find out.
Experts are trying to find out why such unusual seismic activity, which has been shaking the Atlantic volcanic island of São Jorge in the Portuguese archipelago of the Azores, has been shaking for more than two weeks.
As of Tuesday, the island has already suffered almost 27,000 small tremors, and there are fears that this activity could indicate an imminent volcanic eruption for the first time since 1808 or a powerful earthquake.
“This is a mystery to us,” said seismologist Joao Fontiel, explaining that multiple tremors were recorded in other Azores, but not in Sao Jorge. “I still haven’t found a clear answer.”
“The transition from a very small number of earthquakes to thousands is extraordinary,” he said.
The volcanic alert is at level 4, indicating a “real possibility” of a volcanic eruption. But when, where on the island exactly and if it really happens remains unanswered, Fontiela said.
So far, all recorded earthquakes have been of tectonic origin, not volcanic. They reached a magnitude of 3.8. If they are volcanic, then this means that the magma is in motion.
The number of daily earthquakes has decreased in recent days, but experts are not sure if this trend will continue. Ground deformation has already been detected, which is very strange given the tectonic origin and the low magnitude of the shocks, Fontiela said.
The lack of previous research on San Jorge makes it difficult to understand the phenomenon, Fontiela said.
Geologist José Madeira said it was unclear what kind of eruption might occur, adding that previous seismic events at São Jorge in 1580 and 1808 were marked by deadly pyroclastic flows.
Earthquakes in San Jorge occur at average depths of 8-12 kilometers. If a significant number of shocks occur closer to the surface, then an inevitable eruption is coming, Madeira said.
Authorities warned that the situation could drag on indefinitely.
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