From Youtube <br />Title: Best Video of Mount St Helens Volcano Eruption footage <br />https://www.youtube.com/watch?v=ZhvkITCGqK4 <br />Published on Feb 20, 2015 <br />May 18th 1980 Mount St Helens Volcano Eruption footage <br />The large eruption on Mount St Helens began at 8:32 am. <br />The earthquake shook loose the upper northern flank of the volcano. About 3.2 cubic km of of the mountain slid down in a massive avalanche at 250 km/h toward the base of Mount St Helens. <br />The avalanche released extreme pressure on the volcano which began a huge explosion. A 500 km/hr blast of hot gases and fractured rock covered 600 sq km in minutes. 30 seconds after the initial blast the Mount St Helens volcano released a Plinian eruption column of ash which rose to a height of 25 km in 15 minutes. The ash reaches Spokane 430 km away in 3½ hours. From noon until 5:30 pm a burning cloud swept 8 km down the northern slopes of the volcano at 300 km/hr. Mudflows raged down the side of the volcano and were caused by melting of the snow on the mountain. Hope you enjoyed this Mount St Helens video footage hd <br />Best Video of Mount St Helens Volcano Eruption footage HD
