The eruptions last autumn of Mount St. Helens in Washington state, in the USA, reminded the media of the remarkable event almost 25 years ago. Up to May 1980, the volcano stood high above a lovely landscape, a beauty spot with huge forests and a variety of flora and fauna surrounding Spirit Lake.
After some months of rumblings indicating that the sleeper was awaking, Mt. St. Helens exploded at 8.32 am on May 18 1980. It had been preceded by an earthquake (5.1 on the Richter scale) on May 12, and then there were nine hours of explosions on May 18, estimated as equivalent to at least 20,000 atomic bombs. The top 1,300 feet of the mountain were blown away, causing a cloud of dust 95 miles in diameter and 30 miles high!
Within two hours it had spread 150 miles eastwards, covering five states and causing street lights to come on prematurely. Some of the ash was detected 950 miles away. The steam blast demolished enough trees to build 600,000 homes up to five miles away within ten minutes. Some of these trees had been eight feet in diameter and 150 feet tall!
