Researchers Find Trigger for Explosive Volcanic Eruptions
Scientists from the Univ. of Southampton have identified a repeating trigger for the largest explosive volcanic eruptions on Earth. The Las Cañadas volcanic caldera on Tenerife, in the Canary Islands, has generated at least eight major eruptions during the last 700,000 years. These catastrophic events have resulted in eruption columns of over 25km high and expelled widespread pyroclastic material over 130km.
By analyzing crystal cumulate nodules (igneous rocks formed by the accumulation of crystals in magma) discovered in pyroclastic deposits of major eruptions, the scientists found that pre-eruptive mixing within the magma chamber – where older cooler magma mixed with younger hotter magma – appears to be the repeating trigger in large-scale eruptions. The paper is published in the open access journal Scientific Reports.