Tuesday, July 08, 2014

A Major Misconception

I used to think Crater Lake in Oregon was caused by the impact of a meteor or meteorite a gazillion or so years ago. Now that we’ve visited Crater Lake National Park, I’ve learned that this crater is a water-filled volcano.
The mountain’s real name is Mt. Mazama. Over 400,000 years eruptions built the mountain to 12,000 feet. Then a huge explosive eruption, 7,700 years ago, blew the top half of Mazama to smithereens, leaving a deep caldera.
Over the millennia, the deep basin filled with rain water and snow melt, making the deepest lake in the United States—1,943 feet. There are no streams feeding Crater Lake. Just rain and snow melt.

There are several smaller volcanoes showing above the surface of the water, but the newest is developing at the bottom of the lake. That youngster is just 4800 years old.
There are 40 volcanoes in Crater Lake National Park, most of them are extinct. The biggest, the one that holds the lake, is just taking a nap and will explode sometime in the future.
This trip, which I’m beginning to think of as our volcanoes trip (Yellowstone, Craters of the Moon, Mt. Hood and now Crater Lake), has changed my perspective on the stability of the earth. There are lots of volcanoes in the western United States and around the world. Human history is a less than a mere second in geologic time. Volcanologists tell us that some of these volcanoes will erupt in a really big way sometime in the future, but those of us living today, and probably our close descendants, don’t have anything to worry about. But, one wonders, what if…


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