On the 16th March 1980, the first signs of an eruption occurred with a series of small earthquakes, then on the 20th March, a 4.2 magnitude earthquake was recorded beneath Mt. St. Helens. Three days later another 4.0 magnitude was recorded, and that evening the earthquakes began occurring in swarms centered directly beneath the volcano, at a rate of about 15 per hour. By March 25, magnitude 4 events were shaking Mt. St. Helens at a rate of about 3 per hour. On March the 27th, in the morning a loud bang was heard from the Volcano, and a summit eruption was confirmed, after all the ash cleared, a new visible crater was discovered 70 m in diameter. The eruption also created a north flank bulge, the bulge was continually monitored and it