Friday, July 31, 2009

Day 14: Across the Great Divide

That is Science Officer Linda conducting another field demonstration in her mobile classroom. Today's lesson was held as we crossed the Continental Divide. She is illustrating the key trait of the Continental Divide, which is that water drained on the western side pours into the Pacific Ocean whereas water drained on the eastern side eventually pours into the Atlantic Ocean.

LK was obviously not the only smart person who understood this principle. A bikie babe who saw me taking the picture gave her a big thumbs-up. Well, Linda took it to be a big thumbs-up, but to me it looked more like "Would you hurry up and get the hell out of there so I can get my picture taken."

It's really good that LK has assumed the role of Living Font of Knowledge, because our time in Yellowstone Park has been a visit to one of the strangest, most unexpected worlds I have ever been in and I appreciate understanding some of the bizarre things I am seeing.

Like most people, I knew there was a geyser called Old Faithful, and I knew that the park sat on the remnants of a massive supervolcano that had exploded hundreds of thousands of years ago - and many think will one day once again darken the skies of North America.

But the things we saw were better than the best special effects in movies. We saw steaming openings in the ground spewing multi-colored liquids, water bubbling in dozens of holes in the ground, limestone landscapes with blasted trees and steaming vents. More than a couple of times, we would turn a corner in the road and see an entire meadow with massive vents of steam rising in six or seven places.

What's underneath this planet of ours is very close to the surface in this place.

I have downloaded heaps of pictures, and they do a better job of explaining Yellowstone than my words will. But I will give you a quick sense of it.

There were three key places in the park that we enjoyed and each was quite different. The first we went to was West Thumb Geyser Basin.

Here there are dozens of steaming holes in the ground, and the colors around them are phenomenal. The pictures are here but LK thinks they don't show the massive amount of steam in the air rising from so many of the geysers.

A couple of points that were really striking:
1. The thin crust of the geyser field reaches all the way down to Yellowstone Lake, and some of the most interesting things happen when the water spews from the geysers into the water.
2. The vegetation that manages to grow among these geysers is amazing. Some of it is incredibly vivid, obviously benefitting from its closeness to the hot, steaming geysers.

The second place we visited - the Upper Geyser Basin - is the most famous, for it is where the Old Faithful geyser is. And the hundreds of tourists who flock there (and seem to skip the other parts) is testament to how famous that geyser is.

But to be candid, Old Faithful may be the star of this area, but the rest of it was far more interesting to me.

LK and I took about a 2-m ile walk around the geyser field, and we were close enough to dozens of little geysers that we could see the water bubbling in them and smell the sulfur in the gases they were emitting. Those pictures are here.

It was a cool day, but very warm in the geyser fields, as you would expect from what is essentially an outdoor steambath as the heat under the ground keeps forcing hot water to the surface.

And the final spot was Mammoth Hot Springs, which was completely different from the rest.

Here the underlying rock is limestone. In the other geothermal parts of the park, it is rhyolite. (Rhyolite is a volcanic rock, not too awful different from granite.)

The limestone is a remnant of the ancient sea that once covered this area. As part of it dissolves, it ends up leaving this white rock called travertine, which makes the terraces of the Hot Springs. (I won't get a good mark for this essay if Mrs Kennedy figures out I plagiarized the last bit.)

To skip the scientific jargon, let me just say that you end up with places like Angel Terrace in the picture on the left. It's eery and other-worldly. That's not snow on the ground, but white rock, and there are little steaming outlets throughout this desolate place. More pictures here.

We had hoped to see a few more spots in the park, but twice we ended up sitting for more than half an hour waiting for road works to let us through. By the time we got to Mammoth Hot Springs it was late in the day, and we headed out of the park on the north end.

An hour drive and we are staying in Livingston Montana tonight. It's really just a sleepover, and we are the road for a new adventure tomorrow. The science lessons are going on hold. Tomorrow is a history class as we head to Little Big Horn Battle Monument to learn how brave Americans fought off invaders trying to take over their homeland.

No comments: