Mount Saint Helens Part 2

    Mount Saint Helens' story really begins about ten thousand years ago in the Pleistocene Epoch of this, the Quaternary period.

     Its eruptions, like the rest of the Cascade volcanoes, Mount Rainer, Mount Shasta, and Mount Lassen, are governed in part by the rate at which the Jaun de Fuca crustal plate thrust itself under the North American Crustal plate.
     
     Out of the fifteen major active volcanoes in the range, Mount Saint Helens is the most active. In fact, Mount Saint Helens is more explosive and more active, than any other volcano in the contiguous United States; only Alaska and Hawaii have more volcanic activity.

     Saint Helens has been active since pre-historic times. It has had at least twenty spasmodic eruptions over the last four thousand five hundred years. Its beautiful summit cone is only known to be one thousand years old. The oldest known ash and pumice deposits, however, are less than forty thousand years old. The ancient volcanic center itself, is believed to be thirty-six thousand years old.

    Spirit Lake, one of the mountain's many natural lakes, was in act, formed sometime between twelve hundred and eight hundred B.C.E. It formed when an immense mudflow formed a natural dam in a pre-historic river bed.

     Other small lakes in the vincinity include, Merrill, Goat Marsh, McBride, June, Meta, Voo hoo, Ghost, Obscuityy, Parity, Venus, Island, Ryan, Foot, Shovel, St. Helens, and many others. There is only one reservoir in the area however, the Swift Reservoir, and it owes its existence partially to the mountain.

     Many nearby rivers also add to the beautiful geographic scenery of the area as well. Two of the most famous are the North and South Forks of the Tourtle River, and the Columbia River. Other  major rivers in the area are the Green, the Muddy, and the Kalama.

     There are also many creeks that add to the array of natural waterways and scenic beauty. Some of these include Clearwater, Coldwater, Adler, Castle, Marble, Smith, Cougar, Disappointment, Diamond, and Swift.

     Saint Helens' last recorded series of eruptions prior to the twentieth century's devastating series of eruptions in 1980, were between 1832 and 1857, when some occasional steam and ash clouds were observed. There was some minor lava  flows during this period as well, but nothing too spectacular, so the rumbling giant fell back into its restless sleep for the second time in two hundred years.

     During one of its first series of eruptions ever recorded in 1793, the mountain gave off a little steam and ash, but then reverted back into dormancy once more.

     Mount Saint Helens was considered potentially dangerous long before its deadly eruption on Mya 18, 1980. In a report published in 1978 by Dwight Crandeall and Donal Mullineaux of the United States Geological Survey (U.S.G.S.), they warned, "...an eruption is more likely to occur within the next one hundred years, and perhaps even before the end of this century. No one at the time, realized how true his or her warning would turn out to be.

     Scientists recognize Mount Saint Helens as a composite or strato-volcano. A composite or strato in this case means "to change", that is the mountain first forms as a quiet erupting shield volcano, but suddenly for some unknown reasonlater on, its eruptive cycle and eruption patterns change.

     The cycle and patterns are not the only things, which change however, the materials, which are erupted also, change. Instead of constant lava flows, the volcano suddenly starts throwing out rocks, pumice, and other forms of lava, such as volcanic blocks and bombs.  If these products, which have been blown apart in various sizes by terrific pressures, known as pyro-clastics, settle to the ground, they can be known as ash, cemented tuff, pumice, and scoria. Sometimes the pyro-clastics settle to the ground with many natural minerals, such as Sulfur, Silica, and Iron Sulfide. Thus all volcanoes have violent, explosive eruptions at one time or another in their histories.

     One of the best examples of this, is the island of Surtsey, just off the coast of Iceland.  Surtsey began its life under the sea level quietly erupting pillow lavas. On November 14, 1963, Surtsey broke the ocean's surface with repeated steam and ash eruptions from three submerged vents. Within a week, loose cinders torn apart by terrfic pressures and a violent explosions, had built up a loose cone above the level of the sea. By April 1964, Lava started flowing over the loose cinders forming a hard cap. By this time, the violent eruptions had almost ceased.

     

Mount Saint Helens part 1

     Volcanoes are the keys to earth's past, its present and its future. Of Earth's volcanoes, over six hundred are known to be active, and most of these are in specific belts and hot spots spread around the globe. One of the world's most famous, most destructive, and most closely watched and studied is probably Mount Saint Helens.

     Mount Saint Helens, formally as "America's Mount Fuji", and one of the world's most beautiful mountains, stands majestically in picturesque southwestern Washington State amid its other famous breath-taking volcanic neighbors, such as Mount Rainer, Mount Hood, and Mount Shasta in the Cascade Range of the United States.

     The Cascade Range itself, stretches from central British Columbia, Canada, in the north, through the states of Washington and Oregon, finally coming to an end in central California.  The Cascade Range also forms the eastern-most side of the Pacific Ocean's 'Ring of Fire'.  Mount Saint Helens is located fifty miles north of the metropolitan areas of Portland,Oregon and Vancouver, Washington.

     Since pre-historic times, Saint Helens has been known by many names.  Most of these along with many legends and lore, come from western Native American Indian tribes, such as the Flatheads, and the Shoshonis. Many of the most common which appear are: Smoking Mountain, Tah-one-lat-clah (meaning fire mountain), and Loo-Wit, which means "Lady of Fire" or "Beautiful White Mountain" depending on its pronuciation. In 1790, the mountain was finally renamed by the British for a minor diplomat named Baron Saint Helens.

     

coming Soon...

A series on the history of Mount Saint Helens.