Science Fair Project Encyclopedia
Mount Shasta and Shastina from the northwest
|Elevation:||14,179 ft (4,322 m)|
|Latitude:||41° 24′ 33.11″ N|
|Longitude:||122° 11′ 41.60″ W|
|Topo map:||USGS Mount Shasta|
|Age of rock:||< 593 Kyr|
|First ascent:||1854 by E.D. Pearce and party|
|Easiest route:||rock/ice climb|
Mount Shasta, (formerly known as Mt. Sisson until 1922) a 14,179-foot (4,322 m) stratovolcano, is the second-highest peak in the Cascade Range and the highest peak in California outside of the Sierra Nevada . The mountain stands 10,000 feet (3,000 m) above the surrounding area and has an estimated volume of 108 mile³ (450 km³).
Main article: Geology of Mount Shasta
The mountain consists of four separate cones buried atop one another. Shastina 12,300 ft (3,749 m) is the most obvious cone and forms a lesser summit. It has a fully intact summit crater which shows that Shastina postdates the last ice age. The rest of Shasta's surface is relatively free of glacial erosion except, paradoxically, for its south side where Sargents Ridge runs parallel to the U-shaped Avalanche Gulch (the largest glacial valley on the volcano, although it does not presently have a glacier in it). There are five named, yet tiny, glaciers clustered on the mountain's north side.
Shasta receives much less snow than most other Cascade mountains because of its southerly position and the fact that moisture-laden air from the Pacific Ocean must first surmount the Klamath Mountains before it reaches Shasta. The annual snowline on Shasta is therefore above 10,000 ft (3,000 m).
There are many buried glacial scars on the mountain that were originally excavated in glacial periods ("ice ages") of the present Wisconsinian glaciation. Most have since been filled-in with andesite lava, pyroclastic flows, and talus from lava domes.
During the last 10,000 years Shasta has erupted an average of every 800 years but in the past 4500 years the volcano has erupted an average of every 600 years. The last significant eruption on Shasta may have occurred 200 years ago.
Mount Shasta can release volcanic ash, pyroclastic flows or dacite and andesite lava. Its deposits can be detected under two nearby small towns totalling 20,000 in population. Shasta has an explosive, eruptive history. There are fumaroles on the mountain, which shows that Shasta is still alive.
The worst case scenario for an eruption is a large pyroclastic flow, such as what occurred at Mount St. Helens. Since there is ice, lahars would also result. Ash would probably blow inland, perhaps as far as eastern Nevada. There is a small chance that an eruption could also be bigger resulting in a collapse of the mountain, as happened at Crater Lake in Oregon, but this is of much lower probability.
The US Geologic Survey considers Shasta a volcano with a high probability of erupting again.
Native American lore of the area held that Shasta is inhabited by the spirit chief Skell who descended from heaven to the mountain's summit. Since then many other faiths and cults have been attracted to Shasta (more than any other Cascade volcano). Mt. Shasta, California, a small town near Shasta's western base, is a focal point for many of these religions. Some examples: Association Sananda and Sanat Kemara , I AM Foundation, Knights of the White Rose , Radiant School of the Seekers and Servers , Rosicrucians, and Understanding, Inc. . Many of these cults hold that races of sentient beings, obstensibly superior to humans, live on Shasta or visit the mountain in UFOs. There are in fact disk or lens-shaped clouds that form sometimes over the mountain—a fairly typical meteorological phenomenon over high places on the earth. Lenticular clouds are often seen and mistaken for UFOs.
Mt. Shasta is also mentioned in a fictional short story by Robert Heinlein as the home of a group of men who are masters of psychic powers, and who decide to teach the world their powers by enlisting Boy Scouts
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