Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock deb...
Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche. In a few moments this slab of rock and ice slammed into Spirit Lake, crossed a ridge 1,300 feet high, and roared 14 miles down the Toutle River. The avalanche rapidly released pressurized gases within the volcano. A tremendous lateral explosion ripped through the avalanche and developed into a turbulent, stone-filled wind that swept over ridges and topped trees. Nearly 150 square miles of forest was blown over or left dead and standing. At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, gray ash fell over eastern Washington and beyond. Wet, cement-like slurries of rock and mud scoured all sides of the volcano. Searing flows of pumiced poured from the crater. The eruption lasted 9 hours, but Mount St. Helens and the surrounding landscape were dramatically changed within moments. The height was reduced from 9,677 ft (2,950 m) to 8,363 ft (2,549 m), and the domed summit was replaced with a 1 mile wide horseshoe-shaped crater. Here is a photo taken the day before the eruption: #financial_support_div{ display:none; position: absolute; width:300px; height:180px; margin-left: -150px; margin-top: -70px; /*- half of width and height */ top:50%; left:50%; padding: 5px; opacity:0.9; filter:alpha(opacity=90); z-index:1000; background-color:#000; color: white; } .close_box{ background: gray; color:#fff; padding:1px 3px; display:inline; position:absolute; right:1px; margin-right: -13px; margin-top: -13px; border-radius:3px; cursor:pointer; border: 1px #000 solid; } $(document).on("click",".close_box",function(){ $(this).parent().fadeTo(300,0,function(){ $(this).remove(); }); }); Loading the player ... Less