You are not in danger of an imminent supereruption at Yellowstone. At the same time, you aren’t at any immediate risk of a large earthquake causing trouble at Yellowstone. It may seem counterintuitive, but the latter is nevertheless more of a threat than the former. As ever, there are plenty of caveats.
USA Today recently conducted an interview with Dr Mike Poland. He’s the scientist-in-charge at the Yellowstone Volcano Observatory (YVO), and he certainly knows a thing or two about his subject matter.
“The biggest concern we have for Yellowstone is not with the volcano, it’s with earthquakes,” he told the outlet. “There can and there will be in the future magnitude-7 earthquakes.”
Obviously, he’s right. This may come as a surprise to you, as the relentless focus of the histrionic media has been on the potential for a supereruption at Yellowstone. As ever, this paints a false picture of the hazards present at this aesthetically marvelous site.
It cannot be emphasized enough that just because a volcano had a couple of cataclysmic events in its multi-million-year-long history, it doesn’t mean it’ll do it again. Right now, the threat of a supereruption is incredibly low, largely thanks to the lack of molten material down there required to make it happen.
If any volcanic activity does happen again there, aside from all the geothermal wonders already present within Yellowstone National Park (YNP), it’ll be far more likely to be a lava flow or a hydrothermal blast.
Yellowstone is of course an active volcanic center, which is partly why earthquakes happen there all the time.
Just check out the United States Geological Survey’s (USGS) last monthly report on the area: there were 153 quakes within the national park. The largest came in at a 2.5M, and there were even a couple of temporally and spatially linked quake sequences, one featuring 77 tremors and another containing just 12.
Earthquake swarms like these make up 50 percent of the seismicity at YNP. Like other more isolated tremors, they happen for a wide range of reasons, including the stretching of the regional crust, slipping faults, and the movement of superheated hydrothermal fluids.
Thanks to it being one of the most monitored places on Earth, scientists are acutely aware that thousands of quakes happen at YNP every single year. No volcanic activity has occurred after any of these events, most of which are not perceptible by humans. In fact, they’re more educational opportunities for seismologists and volcanologists than anything else.
As Poland notes, you can get large quakes too. On October 28, 1983, a 6.9M tremor rocked Borah Peak in the Idaho section of YNP. It caused plenty of infrastructural damage and killed two people.
Back on August 17, 1959, a 7.3M tremor hit Hebgen Lake in the Montana slither of YNP. It triggered a landslide, and 28 people were killed. So much material was mobilized downslope that it blocked a river and created a brand-new lake.
These infrequent, larger quakes are the hazards he’s referring to. Like all major tremors, they’re quite troublesome: no one can predict when and precisely where such events will occur, which is why research and preparation are paramount.
Either way, a major quake like this at YNP is far more likely to take place within our lifetimes than even a tiny eruption.
The thing is, visitors have been killed by bears, lightning strikes, drowning, geothermal pool burns, and even crushed under a falling tree since YNP was established in 1872 – but such fatalities are comparable to the number of deaths via quake. The risks of anything bad happening to you at YNP are generally very low. So go visit!