I have said time and again that this past summer was stimulating and educational for us, but I know as a blogger that my passions may not match yours so if geology isn’t your thing, feel free to look at the pretty pictures instead. I say this as someone who gave geology a mere passing nod until I supported a couple of naturalist courses on the subject. Now I am spellbound and will never look at Yellowstone the same, nor anywhere else for that matter, where geologic forces come together to create majestic peaks, valleys, and canyons.
I can’t say which of the Yellowstone Forever field seminars I supported was my favorite, but without a doubt I can say that the instructor who led the Thermal Biology and Geology course this summer, Joshua Theurer, is extremely bright, passionate about Yellowstone, and can hold a student’s attention like the most seasoned of instructors. I was fully engaged in both his field seminars I supported and look forward to participating in more of his classes in the future.
Joshua’s “Observing Thermal Geology and Biology” course, which followed on the heels of Virginia’s “Landscape Geology” class (also wonderful), was fortuitous for me (or so I thought), giving me a leg-up, as it were…hardly. This is a complex subject, and we were required to complete an exercise before the end of the course, in order to receive credit for this naturalist class. I could go on and on about everything I learned but instead will touch on some of the highlights, so as not to put anyone to sleep.
Imagine, if you will, the earth as an egg:
- The outer layer of the earth, the crust, is analogous to the shell of the egg. It is ~ 25 miles thick. Yellowstone has a much thinner crust than average, as little as three miles thick in places.
- The mantle, which makes up the bulk of the earth and moves in enormous convection cells, is like the egg white. It averages about 3000 miles in thickness.
- The core of the earth, resembling the egg yolk, is composed mostly of metals and acts as a nuclear reactor, our primary heat source.
There are about two dozen hot spots on earth, with Yellowstone being one of the largest. The theory is that a hot spot originates at the core of the earth and doesn’t move. The continental plates move across them.
Given the 10,000+ hydrothermal features in Yellowstone, one would assume a significant magma chamber below the park, deep in the mantle of the earth, and you would be right. In 2011 the University of Utah’s research concluded that this chamber was at least 400 miles thick and this was all they could determine as their equipment went no further. In 2015 they discovered a “mantle plume” of roughly 1000 miles below the original magma chamber, a reservoir 4.5 times larger than their initial discovery! We now believe there is enough magma below Yellowstone to fill the Grand Canyon 11 times. Although this sounds ominous, given Yellowstone is classified as a “supervolcano”, scientists don’t expect a major eruption is in the park’s near future, and feel that there would be weeks, if not months, of increased seismic activity prior to such an eruption.
Day one our course took us to one to the hottest and most rapidly changing thermal areas in all of Yellowstone – Norris Geyser Basin. Mechanically it functions like other geyser basins but is far more complex, due to the converging of three fault lines beneath it.
Porcelain Basin resides within Norris and was so named for the milky color of the mineral deposits found here.
There are four types of thermal features found within the park:
- Hot springs – most common and have no constrictions. Water continually circulates, preventing the water from reaching a temperature needed to produce an eruption. The deeper the blue color, the hotter the water. Deep blue signifies temps of at least 159º F.
- Geyser – around 500 in the park. These features erupt when the gas bubbles’ surface area is so great that the water is lifted outside the reservoir.
- Mudpot – most acidic, with a pH of 2 or less and a limited water supply. Gases convert rock to clay.
- Fumarole – known as a steam vent, and is the hottest hydrothermal feature in the park. Water is converted to steam even before it reaches the surface, and is usually announced with a loud hissing sound. Temperatures can reach to 280º F. Norris’ hillsides are dotted with these steam vents.
Hot springs, geysers, and fumaroles can be found within the Norris Geyser Basin. I am not aware of any mudpots within Norris, but some can be found just a few miles south at Artists’ Paintpots. The varying colors found within these thermal features are due to special microbes, called thermophiles, that make their home here, and the off-putting smell (think rotten eggs) is due to the elevated levels of sulfuric acid and hydrogen sulfide gas found in the thermal features.
And one of my favorites…
Disclaimer: The views expressed here are my own and do not necessarily represent the views of Yellowstone Forever.
Next Up: Day 2 of Thermal Biology, where travertine abounds.
Paint Your Landscape 
Thanks for the science lesson! Looking forward to the next one.
Although not as pretty as some of the more colorful thermal features in Yellowstone, for some reason I found the mudpots to be especially fascinating.
I find it all to be fascinating! And the idea that those mudpots are created by the breaking down of rock into clay just boggles my mind.
That reminds me of the Geysers of Iceland, I have seen. Seeing one erupting is the best, but still seeing them boil is great too. Nature is so amazing. The biggest and most active one in Iceland was erupting every 4 minutes and it was hard to get away form it, as you keep wanting to see the next eruption. I loved it. I can imagine it was amazingly interesting.
Hello Ute! The geysers of Iceland are on our travel list, so hopefully one day we will get to experience them. Nature is so fascinating!
Fascinating info and photos! Geysers are such interesting natural phenomenons! Great pics!
Peta
Thanks Peta! Our Yellowstone summer was so educational. 🙂
OMG! This is such wonderful information, and your pictures are perfect. I can see why you have been so excited about this summer’s adventures in Lamar Valley. I hope you do go back next year, because I would be excited to see more of what you learned. Thank you for sharing!!!
My pleasure Joan!
This is fascinating stuff LuAnn! And fabulous photos. I have witnessed a bit of geothermal activity in Japan, and recently in the Azores where much of their electricity needs are apparently met by geothermal power plants, but nothing on this scale. Thank you for sharing.
My pleasure Madhu. Your travels have been much more exotic than ours, which is why you are one of my travel idols! We hope to turn our attention more to traveling beyond our borders. Such a fascinating world out there to explore!
I am fascinated by geology, this course sounds amazing! So much of the southwest is covered with incredible geologic formations…very, very cool that you got an in depth lesson.
I found all the courses that I supported to be fascinating Lisa. Yellowstone Forever has designed a Yellowstone Naturalist Certification program, which requires taking 7 naturalist field seminars, over whatever period of time you would like. I was able to support/attend the 4 that were given this past summer. I hope to get this certification some day. It would allow me to support work in the park through the NPS.
Oh how we love Yellowstone. I think Paul and I would have both loved taking that course. We are so very blessed to be able to enjoy God’s gifts. How he thought of making all this beauty for us is amazing.
You have a way with photos to bring out the beauty in everything. The way you captured all the colors in the geyser basins is fantastic. I am with Gayle. I, too, like the mud pots. Thanks for a super science lesson. Helps me to understand the inner workings of these Fire and Ice beauties.
I really could have bored you if I hadn’t just skimmed the surface of what I learned Marsha. 🙂
Love this post!! I think most people have so little time in Yellowstone that there is little to no reading about the features. I thankful that our various visits afforded us the time to really read and learn. It is amazing how varied the features are in Yellowstone. Your header is probably my favorite spot in the park. I understand the park has finally created a place to legally way to view the Grand Prismatic Spring from above!? We hiked a trail we discovered and then climbed a VERY steep hill over a thousand dead tree trunks to see it from above. We almost killed ourselves but it was worth it. I understand that trail was closed and you were ticketed for trying it shortly after our trek. It is such an amazing site! Thanks for refreshing my memory:) Can’t wait for the next post!!
Thanks Pam! I find the hydrothermal features fascinating and to learn that there is a much larger magma chamber sitting below Yellowstone than anyone ever suspected just blows my mind! You are right, there is now a wonderful path that allows visitors to view Grand Prismatic from above. The lookout point that has been created is wonderful. My header shot was taken from this lookout.
When I saw your header, I was wondering if you had been to what I heard was a new lookout. So glad to hear it really did happen. Climbing the hill and downed trees wasn’t fun. I actually jammed my toe and lost half of my nail eventually from that climb:)
I had heard about how challenging that climb was before the lookout was built. We never tried to tackle it when we lived in Yellowstone. It is pretty sweet now.
Amazing post LuAnn. It is unbelievable to think of how the earth works. So incredible. I’d love to bring my kids to Yellowstone someday. I went as a child and was amazed by it.
Nicole, I think everyone should experience Yellowstone at least once. There is so much diversity.
I realize that my husband has never been there either. Another place we must visit! 🙂
We had not been to Yellowstone until later in life, when we lived in the park for two years. The winters especially are amazing!
Thanks for the course, Lu. And the pictures were wonderful. All that blue sky. What planet is Yellowstone on?
My pleasure David. Those Montana big skies are pretty special. Yellowstone is otherworldly, isn’t it?
Looking at the opening photo – I had no idea of the immense size of some of these features. And I’d expect far more people
This is the granddaddy of hydrothermal features, Grand Prismatic. The photo was taken early in the season, so thankfully not as many tourists.
You really captured Yellowstone! Gorgeous captures of an amazing place! Those Hot Springs are something to see! Aren’t they?!?!
It’s been a few years for me since I have been there. So thanks so much for the sweet memories!
My pleasure Nancy! Yellowstone is indeed an amazing place.
I’ve been to many of our national parks (my parents took my brothers and me camping almost every summer, and my love of them has continued into my adulthood) but I’ve never been to Yellowstone. Your geology/history lesson, and especially your beautiful photos reinforce my commitment to get there one day soon. Just amazing.
We too are enthralled with our national parks and have many favorites. I have a particular passion for Yellowstone as it is our first NP. Thanks for stopping by!
What a diverse learning experience you had this summer LuAnn. I’m not a real geology fanatic but oh my the areas you went to and the photos are jaw dropping.
Thanks Sue. I was not a geology buff either until I supported two of the classes this past summer. The thermal geology class really drew me in.
Now I need to go back to Yellowstone with your blog post printed out as a guide! Your analogy of the earth as an egg is really helpful. We spent 10 days exploring Yellowstone a few years ago, and I think the Norris Geyser Basin was my favorite area. I’d love to see Grand Prismatic from the new trail. It sounds so much easier than the old, where I couldn’t get any decent photos! Your photos are wonderful!
Thanks Laurel. We weren’t at Grand Prismatic at the right time of day, but as you know, it isn’t always possible to get to a location at the right time for that perfect photo, or perhaps I am just not as focused as I should be when it comes to photography. 😉
Amazing photographs! Breathtaking.
Thanks so much!
Wow – Your photos are stunning! Of course I loved looking at the “pretty pictures” but, since it’s been years since I took a geology class (and I only remember one), I learned so much from this post. Your example of the egg as a representation of the earth really helped me visualize how the crust, mantle and core related to each other and I could picture the continental plates shifting about in the mantle, too. Such a small thing to grasp but I can understand why the naturalist courses you took, as well as having an up-front-and-personal experience with Yellowstone last summer, would awaken an interest in geology. I’ll be looking forward to more posts in your Forever Field series! Anita
Thanks Anita! I can’t believe we spent two years in Yellowstone and I feel like I was merely a tourist for those two years. All it took was a couple of naturalist courses for me to see through different eyes. 🙂
Very interesting way of learning something new. Thank you for sharing!
My pleasure. 🙂
Impressed with the images, Thank you for Sharing such amazing images 🙂
My pleasure!