40 years ago in Washington: Scientists remain ‘mystified’ as Mount St. Helens activity increases

A bulge near the top of Mount St. Helens was growing on May 3, 1980, and scientists were uncertain what to make of it. The most alarming explanation was that “pressure of molten rock is building within the volcano.”

Even if that weren’t the case, the bulge could trigger a landslide or snow slide, which could reach Spirit Lake or the north fork of the Toutle River.

The next day, the bulge grew even larger. The Goat Rock area on the mountain moved almost 10 feet.

By May 7, scientists were certain that the bulge was caused by molten rock moving up from deep beneath the mountain. They also grew increasingly alarmed that the bulge would collapse and cause a huge mudflow. However, they believed such a mudflow would not endanger any populated areas.

Then, on May 8, Mount St. Helens spoke once again. It spewed smoke and ash for the first time in weeks. The plume went 2,000 feet high.

That same day, scientists discovered a “hot spot” under the bulge, and said the “hazard on the north side of the mountain is greater than at any time” since the volcano began erupting. They also confessed to being “mystified” about the volcano’s ultimate intentions.

Meanwhile, Harry Truman, the elderly owner of the Spirit Lake Resort, refused to leave despite repeated pleas.