Scientists have identified the mechanism behind the tens of thousands of earthquakes, termed an "earthquake swarm," that occurred near the Greek island of Santorini earlier this year. The seismic activity was attributed to molten rock, or magma, pumping through an underground channel over a three-month period. The magma traveled approximately 20 kilometers (12 miles) horizontally through the Earth's crust.
Scientific Methodology
Researchers utilized a combination of physics and artificial intelligence to determine the cause of the more than 25,000 tremors. Each earthquake was treated as a virtual sensor, and artificial intelligence was employed to analyze the associated seismic patterns. Dr. Stephen Hicks from University College London, one of the lead researchers, indicated that this integrated approach of physics and machine learning could contribute to the forecasting of volcanic eruptions.
The Santorini Seismic Event
The seismic activity commenced recently beneath the Greek islands of Santorini, Amorgos, and Anafi. Numerous earthquakes, many exceeding magnitude 5.0, were felt by residents. The activity prompted concerns among tourists and locals regarding a potential eruption of the nearby underwater Kolumbo volcano or a precursor to a larger earthquake, similar to the magnitude 7.7 event in the region in 1956.
Magma Movement and Findings
Findings, published in the journal Science, detail a 3D map of the Earth around Santorini created by the scientists. They mapped the evolving seismic activity patterns and the movement and stress within the crust. The resulting model indicated that the event was driven by the horizontal movement of magma from beneath Santorini and the Kolumbo volcano. This magma traversed a 30-kilometer channel located more than 10 kilometers beneath the seafloor between the islands of Santorini and Anydros.
The research estimated the volume of magma that moved through the crust to be equivalent to 200,000 Olympic-sized swimming pools. These "magma intrusions" are reported to have penetrated rock layers, subsequently triggering thousands of tremors. Anthony Lomax, a research geophysicist and lead author of the study, explained that the tremors functioned as deep-earth instruments, with their patterns in the 3D model aligning with expectations for horizontal magma movement.