Yellowstone National Park sits atop an underground volcano that hasn't erupted for 10,000 years. The underground activity gives the park its hot mineral springs and geysers. So what if it were to erupt again? Would we be able to tell ahead of time? There are four main warning signs: rising land surface, gas emissions, earthquakes, and heat. The trouble is, Yellowstone is known for all those things.
If Yellowstone were marching towards a new eruption, we might expect to see all four of these factors changing rapidly in the same area. However, the other wrinkle is the size of the eruption. It can be very hard to forecast both the timing and size of an eruption. At Yellowstone, the most common eruptions are relatively small — maybe the eruption of a new rhyolite dome that might as big or smaller than the 1980 St. Helens eruption. The three giant eruptions that have happened at Yellowstone over the past two million years are uncommon, so they are the less-likely scenarios if signs of an eruption were coming.
However, with the size of the giant eruption in thousands of cubic kilometers of ash and debris, as opposed to a smaller eruption that might be 5-10 cubic kilometers, the signs of an impending massive eruption would be like nothing we have seen in modern human history. Would the uplift be on the order of tens of meters over many square kilometers? Would it cause the hot springs across the entire basin to heat up dramatically? Would earthquakes be felt in places throughout Yellowstone?
The good news is that scientists are monitoring Yellowstone for all the signs. Read about the Yellowstone caldera and the symptoms of imminent eruption at Discover. -via Strange Company
(Image credit: National Park Service)