Thursday, June 02, 2011

Craters of the Moon

Our day began with a great free pancakes-and-eggs breakfast from the RV Park!

Stuffed, we started off to see the Craters of the Moon National Monument and Preserve, a huge area that has been the site of numerous lava flows in the last 14,000 years or so.

As we drove, we saw some precipitation in the distance. It started to rain. Then it started to snow. Then it started to be a white-out. On June 2, this was our first view of Craters of the Moon:

We stopped in the visitor center, where we met a more unfortunate group than ourselves -- the folks who chose to visit on motorcycles. They bravely went on, while we watched the movie about the park. When we left, it was still snowing, but we could at least see some of the "arms" of lava, now solidified into basalt:
As we drove, the sun started to show itself a bit, although the temperature was still in the 30s and the wind was fierce and cold.

These flows have been happening approximately every 2000 years since about 14,000 years ago. They may have been caused by leftover heat from the same super hot-spot that migrated through the Snake River plain and is now under Yellowstone.

The day kept getting better and better (not warmer, though), and we got to see examples of different types of lava flows. Pahoehoe (higher water/steam content that results in smooth and ropey lava), aa (lower water content lava that solidifies in jagged hunks of basalt), and block lava were visible throughout the park.
The area is still geologically active, and is monitored by seismographs. The pattern seems to be an eruption every 2000 years, and the last one was 2000 years ago. Geologists expect another new lava field to be formed within the next 1000 years. If you want to see the park as it is today, you might want to plan a visit soon!

1 comment:

Sharon Del Rosario said...

Sorry I didn't get your Utah geology book returned before we took off to parts unknown! Also sorry you're having such cold weather. It's in the 60's here in Valdez, AK.