Methana Volcano's 100,000-Year Dormancy Challenges Extinction Classification

A study published April 22 in Science Advances reveals that Greece's Methana volcano, which last erupted around 250 B.C.E., experienced a roughly 100,000-year dormant period between about 168,000 and 280,000 years ago before erupting again. Led by Razvan-Gabriel Popa of ETH Zurich, researchers analyzed over 1,250 zircon crystals from ancient lava flows to reconstruct 700,000 years of activity, documenting 31 eruptions. They found that magma accumulated beneath the volcano even during its quiet phase, due to superhydrous magma from the subduction zone. This suggests that volcanoes currently classified as extinct may pose hidden threats. Co-author Olivier Bachmann states the findings necessitate re-evaluating threat levels for volcanoes quiet for tens of thousands of years. The discovery has implications for subduction zone volcanoes worldwide, including around the Pacific Ocean, Caribbean, and Mediterranean seas.