Researchers confirmed that magma surged beneath São Jorge island in the Azores in March 2022, triggering over 18,000 earthquakes without causing a volcanic eruption.
Magma moved rapidly from depth to near surface in days
The magma ascended from more than 20 kilometres below the island to just 1.6 kilometres depth within a few days, moving approximately 80 million cubic metres of molten rock.
Ground uplift and seismic swarm revealed hidden activity
Satellite data showed the island’s surface rose by about six centimetres due to the magma intrusion, whereas instruments recorded more than 18,000 small quakes linked to the Pico do Carvão fault line.
Study highlights limits of current eruption forecasting
The event demonstrates that significant magma movement can occur without surface eruptions or clear warning signs, challenging existing monitoring methods.
Why did the magma not reach the surface?
The magma stalled at 1.6 kilometres depth, likely due to resistance from overlying rock layers or changes in pressure within the fault system, preventing an eruption despite the volume and speed of ascent.
Can such events be predicted in the future?
Researchers suggest combining satellite deformation data with dense seismic monitoring could improve early detection of similar magma intrusions, though forecasting exact outcomes remains uncertain.
