Two new volcanic ‘super-eruptions’ discovered

A new study published in Geology by Leicester academics has highlighted the discovery of two new super-eruptions originating from the Yellowstone hotspot track, including what they believe was the volcanic province’s largest and most cataclysmic event.

Dr Thomas Knott, a volcanologist at the University of Leicester and the paper’s lead author, and his team identified that the super-eruptions occurred during the Miocene, an interval of geologic time spanning 23 million to 5.3 million years.

The research also highlighted that the frequency of these super-eruptions in the area may be declining, after occurring once every 500,000 years to once every 1.5million years.

Dr Thomas Knott said: “Volcanic super-eruptions have been some of the most extreme events ever to affect the Earth’s surface and have the potential to alter the planet’s climate, however relatively few have been documented in the geologic record.

“The Grey’s Landing super-eruption we discovered in southern Idaho, USA was 30% bigger than the previous record holder. It would have enamelled an area the size of New Jersey in searing-hot volcanic glass, and rained fine ash over the entire United States, gradually encompassing the globe.

“However, it seems that the Yellowstone hotspot has experienced a three-fold decrease in its capacity to produce super-eruption events. The last super-eruption there was 630,000 years ago, suggesting we may have up to 900,000 years before another eruption of this scale occurs.”

The study grew out of a larger NERC-funded project investigating the productivity of major continental volcanic provinces. Those with super-eruptions are the result of colossal degrees of crustal melting over prolonged periods of time, and therefore have a profound impact on the structure and composition of the Earth’s crust in the regions where they occur.

The team used a combination of techniques, including bulk chemistry, magnetic data, and radio-isotopic dates, to correlate volcanic deposits scattered across tens of thousands of square kilometres.

Because studying these provinces is vital to understanding their role in shaping our planet’s crustal processes, Knott hopes this research foreshadows even more revelations. “We hope the methods and findings we present in our paper will enable the discovery of more new super-eruption records around the globe,” he says.