extinct volcanoes – Misryoum reports that zircon crystals from a Greek volcano suggest magma kept forming during long quiet periods.
A volcano that appears “extinct” from the surface may still be cooking underground, according to new evidence from Greece.
Misryoum reports that researchers studying a Greek volcanic system found zircon crystals that point to magma activity during what looked like a long gap between eruptions.. The work centers on Methana. an active volcano about 50 kilometers from Athens. and the idea that dormancy visible at the surface can mask deeper processes.
Volcanoes are often classified as extinct when they have not erupted for roughly the last 10. 000 years. though larger systems can wait much longer between eruptions.. In this study. Misryoum explains. the team turned to zircon. tiny minerals that form in magma chambers deep underground and are carried upward during eruptions.
The researchers analyzed volcanic rock samples and identified zircon in more than 1,250 samples.. By dating those crystals. they reconstructed a timeline spanning hundreds of thousands of years and showed that Methana had at least two major eruptive phases separated by a prolonged interval.. Crucially, Misryoum reports that the zircon record does not disappear during the quieter period.. Instead, it peaks, suggesting magma was still being generated even when surface evidence of eruption was absent.
This finding shifts the focus from whether a volcano erupted recently to what was happening inside the magma plumbing over long timescales.
Misryoum also highlights a possible mechanism for why magma might pause without fully shutting down.. The team proposes that water-rich conditions in the magma could help sustain molten material at depth. but as magma pressure drops on its way upward. water would begin to escape.. In their interpretation. the outgassing could trigger the magma to crystallize and become too stiff to keep rising. stalling before it reaches the surface.
Meanwhile. that same process could help explain why some volcanic systems erupt when they do. rather than smoothly releasing magma continuously.. If water content and crystallization behavior influence whether magma can break through to the surface. Misryoum notes that similar patterns could exist in other volcanoes that have not erupted for long periods.
For hazard planning. the implications are straightforward: Misryoum says connecting magma chemistry and deep activity to a volcano’s long-term cycle may help scientists identify which “quiet” volcanoes deserve closer monitoring. especially those that have not erupted in a while but may still be capable of generating eruptions.