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Old 09-16-2011, 11:38 PM
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Where there is basalt, there are volcanoes.

The Columbia River Basalt Group (including the Steen and Picture Gorge basalts) is a large igneous province that lies across parts of the U.S. states of Washington, Oregon, Idaho, Nevada and California.

During late Miocene and early Pliocene epochs, one of the largest flood basalts ever to appear on the Earth's surface engulfed about 163,700 km² (63,000 mile²) of the Pacific Northwest, forming a large igneous province with an estimated volume of 174,300 km³.

Eruptions were most vigorous from 17–14 million years ago, when over 99% of the basalt was released. Less extensive eruptions continued from 14–6 million years ago.

And those mountains are still with us to this day. Some are considered dormant, however, so was Mount St. Helens...

That mountain has not gone dormant yet, even though she blew her top 30 years ago.

This area is surrounded by volcanoes that have been active as recently as 1907, prior to the Mount St. Helens eruption.

A volcano blowing it's top is not an unknown occurrence. Krakatoa, a massive volcano located between the rock islands of Java and Sumatra in the Sundra Strait, exploded in 1883, killing approximately 40,000 people, although some estimates put the death toll much higher. The explosion is considered to be the loudest sound ever heard in modern history, with reports of it being heard nearly 3,000 miles (4,800 km) from its point of origin. The shock wave from the explosion was recorded on barographs around the globe.

Before the age of scientific instruments, around 5677 BC; the Pacific NorthWest experienced a Krakatoa like eruption of its own. Mount Mazama erupted and literally gutted itself . It formed what is now known as Crater Lake. The eruption reduced Mazama's approximate 12,000-foot height by over a mile. Much of the volcano fell into the volcano's partially emptied neck and magma chamber.

Even though those mountains near us have erupted and have or will slip into dormancy, we are surrounded...

And so, what happens with Mt. Adams, Mt. Ranier, Mt. Hood, Mt. Jefferson, Mt. Thielsen or Mt. Shasta?

Time, and another apocalypse, will tell.
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