Mount St. Helens

Splashery stretches a drumhead over this Splash's outline, twelve inches across, and finds the ways it can ring. Its lowest is 378.5 Hz, 61 cents flat of G4, the nearest tine on the comb. The next fifteen are its overtones, and each one draws its own figure: sand gathers on the lines that stay still.

Tap to play May 18, 1980; tap again to go back to 1979.

Mount St. Helens, a volcano in Washington State, erupted on May 18, 1980. An earthquake set off the largest landslide ever recorded: the bulging north side of the mountain slid away, a sideways blast flattened the forest for miles, and a column of ash rose about 24 kilometers into the sky. The summit was about 400 meters lower afterward, with a horseshoe-shaped crater open to the north.

This block shows the mountain before the eruption, from a U.S. Geological Survey model made from 1950s topographic maps, and today, from the 3D Elevation Program and aerial photographs, seen from the north. Tap it to watch the summit fall away while the blast races north and the ash column rises and drifts east; tap again to go back to 1979. The heights are real; the timing and the ash are shortened to a few seconds.

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