Yellowstone

Michael called a few days ago to tell me that he, Claire, Calum, and Trevor had successfully hitchhiked to the Grand Tetons and were staying in the campground there that night. I have not heard from them since, but they were planning to ride on (yes, actually on their bicycles) to Yellowstone and I can only assume that they were there last night. They are probably riding their bicycles near very smelly hot springs as we speak. I know Michael said that he was excited to see the paint pots too. The weather there is supposed to be cooler and clear, so hopefully it is pleasant riding as they start up again.

I just wanted to talk a little bit about Yellowstone geology because it is near and dear to my heart (my dad wrote a book about Yellowstone, so when I was younger my family would go there yearly). Of course Yellowstone has wildlife (wolves, bears, and bison, oh my!- just a few), flowers, lots of mosquitoes, new growth forest following the fires, etc etc. I could talk a lot about all this stuff, but I'll stick to geology since without that Yellowstone would not be protected and instead probably hunted out and settled like most of the west. 

Yellowstone National Park is a geothermal hot spot area. This means there is an upwelling mantle plume that brings warmer temperatures near the surface and increases active volcanism. The mantle plume is relatively stationary as the crust moves around the Earth's surface, so in the case of Yellowstone it is easy to follow the caldera movement across Idaho and into Wyoming. The number is the date in millions of years ago that the caldera was active.

Now the lovely thing about being a hotspot is that there is increased volcanism in the region. In the case of Yellowstone, right now, this is manifest as hydrothermal activity. We get geysers like Old Faithful, hot springs like Grand Prismatic here, or paint pots. All lovely interesting things to see.



But by far the coolest part, in my opinion, is that Yellowstone is still an active volcano. I keep using the word caldera here. A caldera is just place where land has collapsed following a volcanic eruption. This is why there is a large lake in the middle of Yellowstone: it is the shallowest area in the caldera.  The particular volcano in the Yellowstone area erupts roughly every 600,000 years in a rather large explosions. Ash from some previous explosions has reached far into the midwest and even been as high as 10 feet in Kansas. That is  A LOT of ash. It makes explosions like the one that destroyed Pompeii look like little poofs of air. 

And guess how long it has been since the last eruption? Oh, approximately 600,000 years. That means, geologically speaking, we are due for an eruption any day. Fortunately the USGS (US Geological Survey) has tons of sensors all around Yellowstone to measure any volcanic activity and hopefully the park would be evacuated if there were serious threats. As for now, the park remains relatively placid and entertaining for the many tourists. Maybe the biggest threat to the park right now is global climate change, which has led to drought in many western states. As a result geysers have less water to draw from and their eruptions become less frequent and more unpredictable. I wonder if nature will destroy her own creation before or after we do it for her.