Before the eruptions, scientists have detected some earthquakes beneath the surface of Mount St. Helens. Also there was a bulge at the north side of the volcano. This grew steadily as a day passes and magma being collected within the bulge. At one point the bulge collapsed due to the recent earthquakes and the eruption came about. Also the eruption had triggered a landslide due to the trajectory of the blast. The earthquakes had a magnitude of at least 5.1.The earthquakes were moderately strong, yet they caused the eruption. These earthquakes were some causes of the eruption of Mount St. Helens.
Before the eruption, there was a bulge that was growing within the north flank of the volcano. This was growing at least 3 feet per day and magma was within the bulge. The recent earthquakes made the volcano to erupt laterally instead of vertically. This broke some of the surface of the Mount St. Helens which decreased the elevation of the volcano for many years. About 540 million tons of ash came down within the United States. The eruption mostly affected the areas of Washington. The ash was at a temperature of 600 degrees Fahrenheit and the eruption had lasted for nine hours. According to one of the maps below, the ash from the eruption centered mostly on the northern states. But the ash, starting from Washington, came as far as Oklahoma. The accumulation of ash within the states, ranged from a height of the bare minimum to 5 inches.