Giant Stealth Magma Surge Triggered Earthquakes Beneath Atlantic Island

A massive surge of magma silently ascended from over 20 kilometers underground beneath São Jorge Island in the Azores in 2022, triggering thousands of earthquakes and raising fears of a volcanic eruption. According to a new study led by researchers at University College London and published in Nature Communications, the molten rock rose rapidly enough to fill approximately 32,000 Olympic swimming pools before stalling just 1.6 kilometers below the surface. This event, termed a failed eruption, caused the island's ground to lift by about 6 centimeters. Scientists utilized seismometers on land and the seafloor, alongside satellite and GPS data, to reconstruct the magma's path. The research indicates that the Pico do Carvão Fault Zone acted as both a conduit for the rising magma and a pressure release valve, allowing gases to escape sideways and preventing a full-scale eruption. These findings highlight how large magma intrusions can occur with limited seismic warning during ascent, offering crucial insights for improving volcanic hazard forecasting and understanding the geological reshaping of volcanic islands through underground processes.