Toba Stayed Eruptive 13,600 Years After 74,000-Year Supereruption, Challenging Hazard Models
Updated
Updated · The Brighter Side of News · Aug 22
Toba Stayed Eruptive 13,600 Years After 74,000-Year Supereruption, Challenging Hazard Models
2 articles · Updated · The Brighter Side of News · Aug 22
Summary
New dating of three post-Toba lava domes shows eruptions continued about 4,600 to 13,600 years after the supereruption, indicating the Indonesian caldera stayed mechanically active long after its main blast.
At least 2,800 cubic kilometers of rhyolite erupted in the main event, but later domes appear to have pushed up mostly solidified material rather than fresh molten magma, based on argon, zircon-helium and thermal modeling.
The dome material likely sat for thousands of years at roughly 300 to 425 degrees Celsius—often below the solidus—suggesting renewed eruptions can occur even when a reservoir is not largely liquid.
That finding challenges hazard assessments centered on detecting molten rock alone and points scientists toward broader warning signs such as uplift, fault movement, earthquakes and gas emissions at restless calderas like Yellowstone and Campi Flegrei.