Hello, Jim!
I have been following your blog and every time the subject comes up on retreats in the [U.S.] Northwest, I have the same question. What about the volcano threat from Yellowstone National Park? Would you please comment on this. Thanks, – GCP
JWR Replies: Part of what you are reading in the mainstream media may be sensationalist hype, but there is definitely a long term risk. (An eruption sometime in the next 10,000 years.) The imponderable question is: Is there as significant risk in the short term? Clearly, none of the “experts” really know for certain. Yes, there are signs of increased volcanic activity at Yellowstone, but that could be a short term fluctuation. And yes, Yellowstone blew up at least once before–several thousand years ago–and when it did, it blanketed much of the eastern two-thirds of the North American continent under volcanic ash that was several meters deep, even as far as the east coast. The worst hit area was a swath that extended from Yellowstone through the Great Lakes, to New England, following the prevailing winds. Meanwhile, areas that were upwind (west of Yellowstone) were relatively unscathed.
Even though it was a couple of orders of magnitudes smaller, the eruption of Mount St. Helens more than two decades ago is a good data point. In essence, the lesson learned from St. Helens is: Upwind good, and downwind bad. If you are concerned about Yellowstone erupting anytime in the next couple of generations, then avoid living in the downwind path. Land anywhere at least 100 miles west of Yellowstone should be relatively safe. My personal risk assessment places a new Yellowstone caldera as a very, very low risk within my lifetime, but if it were to happen it would be truly catastrophic. (A classic “low probability, high risk scenario–much like a major asteroid strike or the “sudden pole shift” that alarmists on the Coast to Coast AM radio show talk about.) But, even still, we live west of the Rockies. Yellowstone is just one less risk that we have to worry about.