Friday, October 4, 2013

Mount Shasta


Mount Shasta
Shasta from south.jpg
Mount Shasta from the south, taken near Dunsmuir, California
Elevation14,179 ft (4,322 m) NAVD 88[1]
Prominence9,822 ft (2,994 m)[2]
Ranked 96th
Parent peakNorth Palisade[2]
ListingUltra
Location
Mount Shasta is located in California
Mount Shasta
California
LocationSiskiyou CountyCaliforniaU.S.
RangeCascade Range
Coordinates41°24′33″N 122°11′42″WCoordinates41°24′33″N 122°11′42″W[1]
Topo mapUSGS Mount Shasta
Geology
TypeStratovolcano
Age of rockAbout 593,000 years
Volcanic arcCascade Volcanic Arc
Last eruption1786[3]
Climbing
First ascent1854 by E. D. Pearce and party[4]
Easiest routeAvalanche Gulch ("John Muir") route:talus/snow climb[4]
Designated:1976








Description[edit source]


Due to its relative isolation, Mount Shasta has a high degree of vertical relief and is the second-most prominent peak in California. Here it is seen from Interstate 5near Yreka.
Mount Shasta is not connected to any nearby mountain and dominates the northern California landscape. It rises abruptly and stands nearly 10,000 ft (3,000 m) above the surrounding terrain.[4] On a clear winter day snowy Mount Shasta can be seen from the floor of the valley 140 miles (230 km) south.[9][citation needed] The mountain has attracted the attention of poets,[10] authors,[11] and presidents.[12]

Aerial view of Mount Shasta from the west.
The mountain consists of four overlapping volcanic cones which have built a complex shape, including the main summit and the prominent satellite cone of 12,330 ft (3,760 m) Shastina, which has a visibly conical form. If Shastina were a separate mountain, it would rank as the fourth-highest peak of the Cascade Range (after Mt. Rainier, Rainier's Liberty Cap, and Mt. Shasta itself).[4]
Mount Shasta's surface is relatively free of deep glacial erosion except, paradoxically, for its south side where Sargents Ridge[13] runs parallel to the U-shaped Avalanche Gulch. This is the largest glacial valley on the volcano, although it does not presently have a glacier in it. There are seven named glaciers on Mount Shasta, with the four largest (WhitneyBolamHotlum, and Wintun) radiating down from high on the main summit cone to below 10,000 ft (3,000 m) primarily on the north and east sides.[4] The Whitney Glacier is the longest and the Hotlum is the most voluminous glacier in the state of California. Three of the smaller named glaciers occupy cirques near and above 11,000 ft (3,400 m) on the south and southeast sides, including the WatkinsKonwakiton, and Mud Creek Glaciers.[citation needed]

History[edit source]

The oldest known human habitation in the area dates to about 7,000 years ago, and by about 5,000 years ago, there was substantial human habitation in the surrounding area.[citation needed]
At the time of Euro-American contact in the 1820s, the Native American tribes who lived within view of Mount Shasta included the ShastaOkwanuchuModocAchomawiAtsugewiKaruk,KlamathWintu, and Yana tribes.[citation needed]
The historic eruption of Mount Shasta in 1786 may have been observed by Lapérouse, but this is disputed. Although perhaps first seen by Spanish explorers, the first reliably-reported land sighting of Mount Shasta by a European or American was by Peter Skene Ogden (a leader of a Hudson's Bay Company trapping brigade) in 1826. In 1827, the name "Sasty" or "Sastise" was given to nearby Mount McLoughlin by Ogden.[14] The name was transferred to present-day Mount Shasta in 1841, partly as a result of work by the United States Exploring Expedition.
Beginning in the 1820s, Mount Shasta was a prominent landmark along what became known as the Siskiyou Trail, which runs at Mount Shasta's base. The Siskiyou Trail was located on the track of an ancient trade and travel route of Native American footpaths between California's Central Valley and the Pacific Northwest.[citation needed]
The California Gold Rush brought the first Euro-American settlements into the area in the early 1850s, including at Yreka, California and Upper Soda Springs. The first recorded ascent of Mount Shasta occurred in 1854 (by Elias Pearce), after several earlier failed attempts. In 1856, the first women (Harriette Eddy, Mary Campbell McCloud, and their party) reached the summit.[citation needed]

Clarence King exploring the Whitney Glacier in 1870. This was the first glacier in the continental United States discovered and named. It was named for Josiah Whitney, head of the California Geological Survey.
By the 1860s and 1870s, Mount Shasta was the subject of scientific and literary interest. A book by California pioneer and entrepreneur James Hutchings, titled Scenes of Wonder and Curiosity in California, contained an account of an early summit trip in 1855.[15] The summit was achieved (or nearly achieved) by John MuirJosiah WhitneyClarence King, and John Wesley Powell. In 1877, Muir wrote a dramatic popular article about an experience in which he survived an overnight blizzard on Mount Shasta by lying in the hot sulfur springs found near the summit.[16]
The 1887 completion of the Central Pacific Railroad, built along the line of the Siskiyou Trail between California and Oregon, brought a substantial increase in tourism, lumbering, and population into the area around Mount Shasta. Early resorts and hotels, such as Shasta Springs, grew up along the Siskiyou Trail around Mount Shasta, catering to these early adventuresome tourists and mountaineers.[citation needed]
In the early Twentieth century, the Pacific Highway followed the track of the Siskiyou Trail to the base of Mount Shasta, leading to still more access to the mountain. Today's version of the Siskiyou Trail, Interstate 5, brings thousands of people a year to Mount Shasta.[citation needed]
February 13–19, 1959 the Mount Shasta Ski Bowl obtained the record of 15.75 feet (480 cm) for the most snowfall during one storm in the U.S.[17]
It was declared a National Natural Landmark in December 1976.[18]

Religion and legends[edit source]


Sunrise on Mount Shasta
The lore of some of the Klamath Tribes in the area held that Mount Shasta is inhabited by the Spirit of the Above-World, Skell, who descended from heaven to the mountain's summit at the request of a Klamath chief. Skell fought with Spirit of the Below-World, Llao, who resided atMt. Mazama by throwing hot rocks and lava, probably representing the volcanic eruptions at both mountains.[19]
Italian settlers arrived in the early 1900s to work in the mills and as stonemasons and established a strong Catholic presence in the area. Many other faiths have been attracted to Mount Shasta over the years—more than any other Cascade volcano.[citation needed] Mount Shasta City and Dunsmuir, California, small towns near Shasta's western base, are focal points for many of these, which range from a Buddhist monastery (Shasta Abbey, founded byHoun Jiyu-Kennett in 1971) to modern-day Native American rituals. A group of Native Americans from the McCloud River area practice rituals on the mountain.[20]
Mount Shasta has also been a focus for non-native American legends, centered on a hidden city of advanced beings from the lost continent of Lemuria.[21] The legend grew from an offhand mention of Lemuria in the 1880s, to a description of a hidden Lemurian village in 1925. In 1931, Wisar Spenle Cerve wrote Lemuria: the lost continent of the Pacific, published by the Rosicrucians, about the hidden Lemurians of Mount Shasta that cemented the legend in many readers' minds.[21]
In August 1987, believers in the spiritual significance of the Harmonic Convergence described Mount Shasta as one of a small number of global "power centers".[22] Mount Shasta remains a focus of "New Age" attention.[23]

Geology[edit source]

About 593,000 years ago, andesitic lavas erupted in what is now Mount Shasta's western flank near McBride Spring. Over time, an ancestral Mount Shasta stratovolcano was built to a large but unknown height; sometime between 300,000 and 360,000 years ago the entire north side of the volcano collapsed, creating an enormous landslide or debris avalanche, 6.5 cu mi (27 km3)[24] in volume. The slide flowed northwestward into Shasta Valley, where the Shasta River now cuts through the 28-mile-long (45 km) flow.
What remains of the oldest of Mount Shasta's four cones is exposed at Sargents Ridge on the south side of the mountain. Lavas from the Sargents Ridge vent cover the Everitt Hill shield at Mount Shasta's southern foot. The last lavas to erupt from the vent werehornblende-pyroxene andesites with a hornblende dacite dome at its summit. Glacial erosion has since modified its shape.[citation needed]
The next cone to form is exposed south of Mount Shasta's current summit and is called Misery Hill. It was formed 15,000 to 20,000 years ago from pyroxene andesite flows and has since been intruded by a hornblende dacite dome.[citation needed]

Nearby Black Butte from Weed, California
There are many buried glacial scars on the mountain which were originally created in recent glacial periods ("ice ages") of the present Wisconsinian glaciation. Most have since been filled in with andesite lavapyroclastic flows, and talus from lava domes. Shastina, by comparison, has a fully intact summit crater indicating that Shastina developed after the last ice age. Shastina has been built by mostly pyroxene andesite lava flows. Some 9,500 years ago, these flows reached about 6.8 mi (10.9 km) south and 3 mi (4.8 km) north of the area now occupied by nearby Black Butte. The last eruptions formed Shastina's present summit about a hundred years later. But before that, Shastina, along with the then forming Black Butte dacite plug dome complex to the west, created numerous pyroclastic flows that covered 43 sq mi (110 km2), including large parts of what is now Mount Shasta, California and Weed, California. Diller Canyon (400 ft (120 m) deep and 0.25 mi (400 m) wide) is an avalanche chute that was probably carved into Shastina's western face by these flows.[citation needed]
The last to form, and the highest cone, the Hotlum Cone, formed about 8,000 years ago. It is named after the Hotlum glacier on its northern face; its longest lava flow, the 500 ft-thick (150 m) Military Pass flow, extends 5.5 mi (8.9 km) down its northwest face. Since the creation of the Hotlum Cone, a dacite dome intruded the cone and now forms the summit. The rock at the 600 ft-wide (180 m) summit crater has been extensively hydrothermally altered by sulfurous hot springs and fumaroles there (only a few examples still remain).[citation needed]
In the last 8,000 years, the Hotlum Cone has erupted at least eight or nine times. About 200 years ago the last significant Mount Shasta eruption came from this cone and created a pyroclastic flow, a hot lahar (mudflow), and three cold lahars, which streamed 7.5 mi (12.1 km) down Mount Shasta's east flank via Ash Creek. A separate hot lahar went 12 mi (19 km) down Mud Creek. This eruption was observed by the explorer La Pérouse, from his ship off the California coast, in 1786.[citation needed]

Volcanic hazards[edit source]

During the last 10,000 years Mount Shasta has erupted an average of every 800 years but in the past 4,500 years the volcano has erupted an average of every 600 years. The last significant eruption on Mount Shasta may have occurred about two centuries ago.[citation needed]

Diller Canyon on Shastina from Weed, California
Mount Shasta can release volcanic ashpyroclastic flows or dacite and andesite lava. Its deposits can be detected under nearby small towns totaling 20,000 in population. Mount Shasta has an explosive, eruptive history. There are fumaroles on the mountain, which show that Mount Shasta is still alive.[citation needed]
The worst case scenario for an eruption is a large pyroclastic flow, such as what occurred in the 1980 eruption of Mount St. Helens. Since there is ice, such as Whitney Glacier and Mud Creek Glacierlahars 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 when Mount Mazama in Oregon collapsed to form what is now called Crater Lake, but this is of much lower probability.[citation needed]
The United States Geological Survey considers Mount Shasta a dormant volcano that will likely erupt in the future and rates it as a very high threat volcano.[25]

In society[edit source]


Mount Shasta's west face. June 2009
Many climbers attempt the summit of Mount Shasta. The summer climbing season runs from late April until October, although many attempts are made in the winter.[4] In winter, Sargents Ridge and Casaval Ridge, to the east and west of Avalanche Gulch[26] respectively, become the most traveled routes, to avoid avalanche danger. Mount Shasta is also a popular destination for backcountry skiing. Many of the climbing routes can be descended by experienced skiers, and there are numerous lower-angled areas around the base of the mountain.[4]
  • Joaquin Miller sets his historical novel, Life Amongst the Modocs,[10] at the base of Mount Shasta. The poet had spent a number of years as a young man living with and near the Native Americans around Mount Shasta, and based this work on that time.
  • California Speed, a 1998 arcade video game (also released for the Nintendo 64 in 1999), has a level where the player races around and through Mount Shasta.[27]
  • Shasta, a line of soft drinks named after Mount Shasta and an associated spring.