Skip Navigation

  Button that takes you to the modules and activities page. Button that takes you to the teacher pages. Button that takes you back to the home page. Button that takes you to the Problem Based Learning model. Button that takes you to the references page.Imape map of some Volcanoes puzzle pieces.  Please have someone assist you with this.

Button that takes you to the  Narrative of Mount St. Helens: page 3. Button that takes you to the Narrative of Mount St. Helens: page 1. Image that says Narrative of Mount St. Helens: page 2. Image of Mount St. Helens from the south face taken from less than three miles away during the height of the May 18th eruption.  This image links to a more detailed image.The Main Eruption On May 18, a quiet Sunday morning, a few volcanologists were at their stations, watching Mount St. Helens. A few tourists and loggers were also nearby. At 8:32 A.M. a small aircraft with two geologists aboard flew directly over the central cone. Eleven seconds later, a strong earthquake shook Mount St. Helens, and the whole north face of the mountain broke free and slid downward as a giant rock avalanche. In seconds, as the rock slid off the mass of hot lava inside the mountain, pressure in the lava dropped, and water that had been dissolved in the lava turned into superheated steam, which formed bubbles that violently expanded and fragmented the lava into a fine powder ash. This mass of superheated steam and ash blasted upward and outward over the top of the avalanche, roaring to the north and west at speeds reaching hundreds of miles an hour. The pilot of the small aircraft narrowly avoided disaster by putting the "plane into a steep dive to gain speed" and turning sharply south, away from the expanding ash cloud. Photo: Courtesy of NGDC/NOAA, (D. Wellman).

Image of Mount Saint Helens viewed from the north on June 4, 1980.  This image links to a more detailed image.Every living thing within about 10 miles of the volcano on the north side--tree or bush, human or beast, scientist or layman--was doomed. Some of the people took a few quick pictures. Then, realizing their situation, most ran or tried to drive away from the approaching cloud of dust and steam. The near-supersonic lateral blast of rock, ash, and hot gas engulfed the area with a force sufficient to strip huge trees bare and uproot or break them off at ground level. The temperature within the cloud reached 500F, sufficient to kill, cause serious burns, and start fires. The rock avalanche roared over Spirit Lake and the valley of the North Fork of the Toutle River, burying them under layers of rock up to several hundred feet thick. Photo: Dept. of Natural Resources, State of Washington. Courtesy of NGDC/NOAA.

Image of surface details of the debris (mud) flow on the North Fork of the Toutle River near Coldwater Creek.  This image links to a more detailed image.Moments after the outrush of the avalanche and ash cloud, enormous mudflows slid off the mountain. These pasty mudflows formed when the glacial ice and snow that had capped the mountain were melted by the intense heat and mixed with the powdered and fragmented rock created by the eruption. The resulting hot and cold masses of mud poured down adjacent river valleys, sweeping away buildings, vehicles, trees, and bridges. One flow even blocked the shipping channel of the Columbia River, 55 miles downstream. Photo: Dept. of Natural Resources, State of Washington. Courtesy of NGDC/NOAA.

Image of ash fall at Sand Point, Idaho, more than 300 miles northeast of Mount Saint Helens.  This image links to a more detailed image.In addition to the ash cloud that stayed near the ground, millions of tons of fine ash were thrown high into the air and carried hundreds and thousands of miles downwind. These clouds, easily seen in satellite images, dropped several inches of ash over many communities and agricultural areas, ruining machines and crops. Photo: Courtesy of NGDC/NOAA, (D. Schoolcraft).

[ Narrative of Mt. St. Helens: page 1 / page 2 / page 3 ]
[ References ] [ PBL Model ]

[ Home ] [ Teacher Pages ] [ Modules & Activities

Button that takes you back to Volcanoes main page.


HTML code by Chris Kreger
Maintained by ETE Team
Last updated November 10, 2004

Some images 2004 www.clipart.com

Privacy Statement and Copyright 1997-2004 by Wheeling Jesuit University/NASA-supported Classroom of the Future. All rights reserved.

Center for Educational Technologies, Circuit Board/Apple graphic logo, and COTF Classroom of the Future logo are registered trademarks of Wheeling Jesuit University.