mtf dating advice - Carbon dating at mount saint helens

Deep in the warm, soft, convecting mantle of the planet, in some places a rising tower of hot rock forms and then lasts for quite a while.

Some of these rising towers may come all the way from the base of the mantle where it meets the core; others may start shallower.

Helens has also been the most active of the Cascades volcanoes over the most recent centuries.

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When a new hot-spot first rises from below, the top must push through the mantle and crust, and the resistance of the stuff in the way of the rising column causes its top to spread out like the head of a thunderhead, or of a mushroom cloud from an atomic bomb, or of a blob in a lava lamp, and for the same reasons.

When that wide head reaches the surface, immense lava flows can be produced that spread across state-sized areas and bury them hundreds of feet deep.

(To see something that looks vaguely like the formation of such a hot spot, go back and view again the “lava lamp” film of Dr.

Anandakrishnan in the introductory material to this unit.) As the lithosphere drifts overhead, the hot spot may “punch through” to make a volcano.

Much of central and eastern Washington and Oregon is buried by the “flood basalts” from the head of the Yellowstone hotspot.

As the continent has moved across the hot spot after it reached the surface, a string of volcanoes erupted including Craters of the Moon National Monument in Idaho.

On the morning of May 18, 1980, Professor Voight’s prediction came frighteningly, awesomely true. A large earthquake either caused, or was caused by, failure of the north side of the mountain in a giant landslide.

Like pulling the cap off a hot, well-shaken soda bottle, the liquid beneath flashed into froth, driving an eruption 12 miles (20 km) high.

They recommended evacuation for safety, and most people (but not all, including some scientists) were moved out of the way.

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