The Mount St. Helens National Volcanic Monument
More Mount St. Helens
The Mount St. Helens Volcano has shown continuous intermittent volcanic activity since the 1980 eruption, including minor eruptions of steam and ash, and occasional pyroclastic flows. More than a dozen extrusions of lava have built a mound-shaped lava dome in the new crater. Goat Rocks on the northern flank is one of the older lava domes. Experts monitoring the volcano believe there will be adequate warning of the next eruption.
The most recent seismic activity occurred October 2004 and consisted of steam and ash eruptions and lava extrusions resulting in the significant expansion of the lava dome.
Understandably, Mount St. Helens has been studied intensively, and more is known about its eruptive history than that of any other Cascade volcano. It is a relatively "young" volcano, perhaps 40,000 to 50,000 years old. The cone that partly collapsed in 1980 is only 2,200 years old. In the last 515 years, it is known to have produced 4 major explosive eruptions and dozens of lesser eruptions. An eruption in 1480 A.D., was about 5 times larger than the May 18, 1980 eruption,
The May 18, 1980 eruption came after nearly 2 months of thousands of local earthquakes and hundreds of steam eruptions, and the outward growth of the volcano's entire north flank by more than 80 meters. A magnitude 5.1 earthquake struck beneath the volcano, sending the volcano's bulging north flank sliding in the largest landslide in recorded history. This in turn triggered a lethal lateral blast of hot gas, steam, and rock debris lasting only a few minutes, but which swept across the landscape as fast as 1,100 kilometers per hour. The next 9-hours of continuous eruption, were followed by 3 days of intermittent eruptions, then 5 smaller explosive eruptions over a period of 5 months.
Altogether, about 4 billion cubic yards of new and old lava material and about 170 million cubic yards of glacial snow and ice were deposited over the landscape, as a result of the May 18 eruption. Some debris and mud-flows, were so voluminous that they reached and blocked the shipping channel of the Columbia River about 70 river miles from the volcano. The eruption itself blew volcanic ash more than 15 miles into the air, within minutes. Winds carried about 490 tons of ash generally eastward across the United States and, in trace amounts, around the world. The ash fell in troublesome amounts as far east as western Montana. About 60 persons were dead or missing.
Best selection of books on the Northwest.
A Falcon Guide to Mount St. Helens: A Guide to Exploring the Great Outdoors by Fred Barstad. This book is a comprehensive guide to this world-renowned attraction, with a close-up look at the destruction and recovery of the area. The guide includes detailed information on the natural and cultural history of the area, recreational opportunities, and historical, geological, and natural exhibits. Order now...
In the Blast Zone: Catastrophe and Renewal on Mount St. Helens by Charles Goodrich, Kathleen Dean Moore and Frederick Swanson. This book presents a cross-pollination of literary and scientific perspectives on the mountain's history of cataclysm and renewal. Discover the gifts of beauty, scientific illumination and of hope. Order now...
Portrait of Mount St. Helens: A Changing Landscape by Chuck Williams (Author) and Stuart Warren (Contributor). View the grandeur and the intimate detail of this beloved mountain as seen by 19th-century painters and pioneers as well as contemporary photographers. Order now...
Day Hiking, South Cascades by Dan Nelson. Introducing next-generation trail guides for the Northwest. More day hikes, with options for extending the trip; hike selection conveniently arranged by highway and travel corridors; more hikes close to urban centers; more year-round hikes at low elevation; clear driving directions; a portable size; and more use of color. Order now...
Selected Climbs in the Cascades Volume II by Jim Nelson and Peter Potterfield. Features 100 routes, including top favorite sport and crag climbing areas. Illustrated throughout with black and white photographs, several with route overlays. Highlights fun, quality climbs for all skill levels. Order now...
Washington Off the Beaten Path, 9th Edition (Off the Beaten Path Series) by Chloe Ernst. This book features the unique things to see and do from quirky cultural tidbits to hidden attractions and unique finds to local dining. Travel off the beaten path for a one of a king experience. Order now...
Go Northwest!® gonorthwest.com (tm)
gonorthwest.com (tm) and GoNorthwest.com (tm) are trademarks of Go
All original text, maps, photographs, and other images on this web site, as well as the compilation and design thereof, are
Copyright © 1997-2014 Go Northwest, LLC. All rights reserved.