Earth: the current frontier. These are the voyages of Prius Señor Fuego. Its mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where others have gone before.
As mentioned earlier, we are moving away from a epistolary format to a more topic based one, due to how we had to double back to see geysers and wildlife.
I understood the basics of hot pools reasonably well: as we go deeper into the crust, the water gets hotter. The warmer water transfers heat to the cooler water, raising the temperature and the pressure. The increased pressure causes the water to boil over. Mud pools are similar, except that dirt has mixed with the boiling water.
Geysers were odd, because they have explosive episodes after which they are quiet. The basic physics is the same: water is heated at lower levels, and pressure builds leading to the explosion. But why don't they boil over continuously (i.e. why aren't they just hot pools?). I ended up looking up the mechanism; it requires that there are side pools to allow the pressure to build up. I found a nice explanation (via YouTube):
Getting all of these condition(side pools or "plumbing system", access to geothermal heated water, outlet to the surface) is somewhat difficult; this helps explain why geysers are so rare!
Old Faithful (erupts every 91 minutes)
Old Faithful Geyser
This is the most frequently geysers in the park.
Grand Geyser (erupts every 7.5 hours)
Grand Geyser
Of all the predictable geysers in the world, Grand Geyser has the tallest spray. The eruptions range from 150 to 200 feet at their maximum. Getting a good sense of scale was difficult; here is a failed attempt:
Attempt at scale for Grand Geyser. Note to others who want to try this; don't use a wide angle -- the nearby people look too large!
Morning Fountain (not predictable)
Morning geyser: Telephoto with people close gives a much better impression of scale
Castle Geyser (erupts every 13 hours)
A final image of Castle Geyser (from the top of post)
The first geothermal activity we encountered in Yellowstone was on the Eastern side (between Tower-Roosevelt and Canyon Village). Similar sites are scattered across the park, but these made a particular impression on us. It is difficult to say whether that is because they were intrinsically interesting, or if it was lack of familiarity.
Mud Volcano: novelty probably won this battle
Looking back, the Mud Volcano was not much to look at. Across the road, however, was the Dragon's cave. The name and the plateau outside the entrance looked like it may hole more appeal.
Outside the dragon's mouth cave
When the wind was blowing in just the right direction, the dragon's cave lived up to its name:
Dragon's mouth cave: probably would have made it without the novelty factor
Note:
I wonder who gets the privilege of naming the sites in Yellowstone. There are some very poetic and descriptive names (such as Dragon's [mouth] cave), descriptive names with some thought (Old Faithful, Castle Geyser), boring descriptive names (Riverside Geyser), not-at-all useful names (Grand Geyser, Giant Geyser -- what is the difference?), and finally just plain old boring names (Norris Geysers, presumably named after Norris).
