Painted Desert

Painted Desert

Wednesday, July 01, 2009

Yellowstone

Two very special milestones today. The most important one is that this is my 100th post. The other is that it's my birthday. It's also our last full day at camp, and we're currently cleaning. Well, my roommates are cleaning, I'm writing a blog entry. Later today we will be going on a fossil collecting field trip just for fun. Some of us will, anyway. The people who stayed up till 7 AM finishing their paper will probably be taking a nap.

Here, my roommate Jordan and I frolic in wildflowers at a stop to look at some glacial geology. What you cannot see is the swam of approximately 1,000 mosquitoes following us.

Here, a portrait of the vans. The green one is full of coolers of food for our 8-day trip. The other vans were carrying 27 people, who are all behind me looking at the Tetons.

Tyson and I. The spire in the background is Grand Teton, which is a glacial arete (ah-RETT). An arete is a peak that is horn-shaped (like the famous Matterhorn in Switzerland) from having been worn away on three sides by glaciers. Glaciers are the most effective means of erosion... far better at removing rock than water, wind, frost, gravity, plants or any of the other means mountains are eroded. However, the steep slopes of glacial aretes will not last for long. They are not very stable. So the aretes we see today are quite young. Speaking of young, the Tetons themselves are some of the youngest mountains in the world, being raised just 9 million years ago. For comparison, the Appalachians are 350 million years old.

We camped at Colter Bay in the Tetons. The best part of camping here was getting to wander around and look at the mountains in our free time. Our first night, we went to watch the sun set:

For some reason, Jordan and Charles decided to make pebble angels on the beach:

video

While there, Jordan pondered why the beach had only pebbles and no sand, which is a very good question you might ask yourself sometime. My best answer is that there is no source of sand. Beaches need a source, a river carrying sand into the region. Sand takes a while to form, being worn down from rocks that have broken out of the mountains. The mountains are very close to the lake here, which means the rocks don't get a chance to bang around in the rivers enough to turn into sand before they're deposited in the lake. The smallest they manage to get is pebble-sized.

I say that sand comes from mountain rocks because this is basically the story of geology: things get worn down from high points and deposited in low points. The earth "wants to be flat." Plate tectonics is always messing things up, thrusting up new blocks of crust, but the higher a piece of crust gets, the steeper its sides are, and the more energy the streams rushing down those sides will have. So the higher something is, the faster it gets eroded. The highest rates of erosion in the world right now are in the Himalayas. The rock is stripped from the mountains and brought down by streams into valleys and the ocean, which it fills in. The mountains are brought low and the low places are raised up. Until plate tectonics messes it up again.

The next day, it rained and rained. We went to see the Gros Ventre (pronounced "grow vont") slide, which is one of the most famous landslides in the world. According to the interpretive sign, in 1925, "some 50 million cubic yards of rock, about a mile long, 2000 feet wide and several hundred feet deep in places plunged down and formed a dam 225 feet high" on the Gros Ventre River. Two years later the dam burst and the town of Kelly, downstream, was practically wiped out.

Heavy rains are suspected to have contributed to the landslide.

You can sort of see the slide here, through the heavy rains.

We tried to find dry places to work on our final mapping project that afternoon. I huddled in the visitor center auditorium trying to focus on my work while an interesting video on one of Yellowstone's wolf packs was playing. Some other students worked in the restaurant.


The skies cleared for a while later. Here, another gratuitous sunset picture.

But the next day, clear blue skies for our introduction to Yellowstone. We saw Old Faithful and I think it was very pretty. It shot out sprays of brilliantly sparkling water against the cloudless sky. I also saw several smaller geysers erupting, like Sawmill Geyser.

Here is a video of the same.

video

And another of Spasmodic Geyser, which was cute:

video

We saw Grand Prismatic Spring, which is famous for being on the cover of National Geographic once.

The beautiful colors are created by different kinds of microorganisms which thrive in different temperatures. The ones that like it hottest are the cyanobacteria that color the center blue.

Here is Grand Prismatic from eye level. The steam rising from the springs is reflecting the colors of the water below it.

We visited Mammoth Springs too; here are some terraces formed by the hot spring water:

And some goofy people.


There are plenty of geological wonders in Yellowstone that are not hydrothermal.

Here we have columnar basalt. These columns are formed when a flow of basaltic (low-silica, high-temperature) lava cools quickly. It fractures into these usually hexagonal columns.

Here in the distance are two flows of columnar basalt in the cliff face.

Finally, we visited the falls in Yellowstone...

These are really very grand and if you see them you will understand why artists come here to paint them. It looks like a painting already.

The stone here is actually yellow, hence the park's name. I believe it's yellow from microorganisms, not the rock itself.

A painting-like shot of the falls.

Well, that's it for now... we're having a party tonight, of course, not for my birthday, but for it being the last day of field camp. I will have to talk about our final fossil-collecting trip later. I also have a couple more entries sure to come, about sundry things I haven't spoken of yet, such as the wildlife of Wyoming.

Nebraskan farm girls gone wild! Also, buffalo.

1 comment:

Mom said...

Happy birthday! I thought about you all day yesterday.

Love,

Mom