The Big Bang

We drove up to Mount St. Helens yesterday to view the devastation from the May 18, 1980, eruption. The eruption was triggered by an earthquake which caused a massive landslide that covered 14 miles of river valley to an average depth of 150'. The landslide released trapped magma and gas producing a lateral blast of hot rock and ash. In less than 10 minutes, 230 square miles of trees were leveled. The mountain lost 1300' of height and .67 cubic miles of volume. Cement like slurries of glacial melt and boulders called lahars scoured and buried streams draining the volcano. An ash eruptions rose 15 miles up from the crater and lasted 9 hours. Avalanches of pumice and hot gasses called pyroclastic flows, shot down slopes to the north.
A number of people were killed or went missing (30-40). The eruption occurred on a Sunday morning. On Monday, thousands of loggers would have had little chance of survival. But as bad as it was, the blast was small in comparison to some previous ones. One quite a bit larger occurred in 1800. And evidence suggests that 3500 years ago an eruption occurred which left a vein of pumice from a pyroclastic flow a meter thick which runs all the way north over Mt. Ranier and into British Columbia. About 40 times more powerful than the 1980 blast.
The Visitors Center on the way in is run by Washington State Parks and had a terrific movie about the lead up to and the day of the blast. Some stories of survivors are remarkable. We continued out to the Johnson Ridge Observatory which is about 5 miles away from the still active crater. We caught a young Ranger giving a presentation on the events as we looked over the site. People were spellbound by the scope. The volcano has developed a lava dome and material is still flowing in at an amazing rate. The new dome is at 1300 feet. Unfortunately, clouds obscured our site into the crater, but the surrounding area is spectacular. As President Jimmy Carter said when he was flown over the area, "It makes a moonscape look like a golf course."
We got back and headed over to Brad and Kim's where they prepared the Peruvian national meal, ceviche, which is raw fish, in this case cod and tilapia, marinated in lime juice and spices, served with a sauted sweet potato. The acid in the lime juice "cooks" the fish. It was great.