Nature Notes

Vol. VIII December, 1930 No. 13

Believe it or not!

Did you ever stop to consider just how a volcano works? Of course it is only theory for no one has as yet dissected a volcano while it was active to observe and tabulate the reactions of its inner self. Rainier is a volcanic cone and no doubt it came into being in this manner.

First at a depth below the surface of the earth in some long, forgotten time the magma or molten rock presed toward the surface possibly throuhg some fracture in the outer crust. With these rising lavas there was also much gas that advanced ahead of the lava and thus both the gas and the lava pressed toward the surface gradually accumulating force and power under the pressure as its advance was hindered by the solid material above. And then finally this flow of motlen rock and gases achieved enogh power to burst through the surface. First, possibly, there was an explosive action as the gases burst upward and this was followed by more quiet flows of the lavas that welled out over the surface and inundated, in succeeding eruptions and lava flows, over 100 square miles of surrounding country which is the area of "The Mountain's" great base.

And in that manner eruptions followed one another when the pressure within the throat of this fire mountain achieved enough power to burst through the "plug" of hardened lavas which solidified after each flow. Rainier hasn't been active for several thousands of years and there is apparently little chance of its becoming active again but it stands today - a magnificent volcanic shaft, its flanks glistening with the greatest glacial system in continentaly United States, - a monument to nature's power in its wildest moods.

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