Lurking beneath Yellowstone National Park is one of the most destructive natural phenomena in the world: a massive supervolcano.I first came across this story in a documentary the BBC aired back in February 2000. Interestingly, given recent events, the United States Geological Survey team at the University of Utah seems to think the BBC “sexed-up” its report. Here's what they have to say about it:
Only a handful exist in the world but when one erupts the explosion will be heard around the globe. The sky will darken, black acid rain will fall, and the Earth will be plunged into the equivalent of a nuclear winter. It could push humanity to the brink of extinction.
The term supervolcano has no specifically defined scientific meaning. It was used by the producers of a British TV program in 2000 to refer to volcanoes that have generated Earth's largest volcanic eruptions. As such, a supervolcano would be one that has produced an exceedingly large, catastrophic explosive eruption and a giant caldera. Because Yellowstone has produced three such very large caldera-forming explosive eruptions in the past 2.1 million years, the producers considered it to be a supervolcano.This time around the story is running on the back of news of the discovery of a huge bulge underneath Yellowstone Lake, the closure of a portion of the Norris Geyser Basin due to increased ground temperatures and a recent earthquake just outside the National Park. To some people this points to impending disaster.
Luckily the guys at USGS are on hand to debunk the whole thing. In their update of current activity at Yellowstone, they note that there is no connection between recent events and the likelihood of a massive eruption.
It is unlikely that there is a connection or triggering mechanism of the earthquake with the increased hydrothermal activity at Norris Geyser Basin, which is about 35 miles from the epicenter, or with hydrothermal features in Yellowstone Lake that have received recent publicity.Ian Gurney had access to the USGS information but he ignores their interpretation of events in favour of quotes like this from Professor Bill McGuire, at University College London:
[The Yellowstone supervolcano] has been on a regular eruption cycle of 600,000 years. The last eruption was 640,000 years ago, so the next is long overdue.So, is it true that the next eruption of Yellowstone is long overdue? Let's hear it from the guys at USGS one last time:
No. The fact that two eruptive intervals (2.1 million to 1.3 million and 1.3 million to 640,000 years ago) are of similar length does not mean that the next eruption will necessarily occur after another similar interval. The physical mechanisms may have changed with time. Furthermore, any inferences based on these two intervals would take into account too few data to be statistically meaningful. To say that an eruption that might happen in ten's or hundred's of thousand's of years is "overdue" would be a gross overstatement.The bottom line: Yellowstone’s going to blow big-time at some point, and when it does we’ll all be in deep, deep trouble but recent events don’t make it any more likely that it's going to happen sooner rather than later.
