Mount Rainier

2007 Schools Wikipedia Selection. Related subjects: North American Geography

Mount Rainier

Mount Rainier as viewed from the Sourdough Ridge trail.
Elevation 14,410 ft (4,392 m)
Location Washington State, USA
Range Cascades
Prominence 13,211 ft (4,026 m) Ranked 21st
Coordinates 46°51′11.9″N, 121°45′35.6″W
Topo map USGS Mount Rainier West
Type Composite volcano
Age of rock < 500,000 yr
Last eruption 1854
First ascent 1870 by Hazard Stevens and P.B. Van Trump
Easiest route rock/ice climb via Disappointment Cleaver

Mount Rainier is a composite volcano in Pierce County, Washington, located 54 miles (87 km) southeast of Seattle, Washington, in the United States. It is the highest peak in the Cascade Range, with a topographical summit of 14,411 feet (4,392 m). The mountain and the surrounding area comprise Mount Rainier National Park. The mountain is mostly covered by snow and glaciers, but heat from the volcano keeps areas of the crater rim on its summit cone mostly free of snow and ice. The geothermal heat has also caused the formation of glacier caves in the twin summit craters.

Mount Rainier was originally known as Talol or Tahoma (not to be confused with Tacoma), from the Puyallup word təqʷúʔʔ ("mother of waters"). It has a topographic prominence of 13,211 feet (4,026 m), greater than that of K2. It can be seen prominently to the south from most of the Seattle Metropolitan Area. On clear days, it can also be seen from as far away as Portland, Oregon. Because of its scenic dominance, Seattle/Tacoma-area residents often refer to it simply as "the Mountain."

Mountain climbing on Mount Rainier is difficult. It includes climbing on the largest glaciers in the U.S. south of Alaska and most climbers require two to three days to reach the summit, with weather and conditioning being the most common reasons for failure. Climbing teams require experience in glacier travel, self-rescue, and wilderness travel. About 8,000 - 13,000 people attempt the climb each year , about 90% via routes from Camp Muir on the southwest flank. Most of the rest ascend Emmons Glacier via Camp Schurman on the northeast. About half of the attempts are successful. About two to three mountaineering deaths each year occur due to rock and ice fall, avalanche, falls, and hypothermia associated with severe weather.

Hiking, photography, and camping are very popular in the park. There are several hiking trails, including the Wonderland Trail, a 93-mile circumnavigation of the peak. Mount Rainier is also popular for winter sports, including snowshoeing and cross-country skiing.

The Carbon, Puyallup, Nisqually, and Cowlitz Rivers begin at eponymous glaciers of Mount Rainier. The sources of the White River are Winthrop, Emmons and Fryingpan Glaciers. The White and Carbon join the Puyallup River which discharges into Commencement Bay at Tacoma, the Nisqually empties into Puget Sound east of Lacey and the Cowlitz joins the Columbia River between Kelso and Longview.

Geological history

Mount Rainier with its main summit, Columbia Crest (14,410 feet) at the center. Massive Emmons Glacier covers most of the visible flank of the mountain. Left of the glacier is sharp pointed Little Tahoma (11,138 feet) with Frying Pan Glacier on its flank.
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Mount Rainier with its main summit, Columbia Crest (14,410 feet) at the centre. Massive Emmons Glacier covers most of the visible flank of the mountain. Left of the glacier is sharp pointed Little Tahoma (11,138 feet) with Frying Pan Glacier on its flank.

Mount Rainier's earliest lavas are over 840,000 years old and are part of the Lily Formation (2.9 million to 840,000 years ago). The early lavas formed a "proto-Rainier" or an ancestral cone prior to the present-day cone. The present cone is over 500,000 years old (Sisson 1995). The volcano is highly eroded, with glaciers on its slopes, and appears to be made mostly of andesite. Rainier likely once stood even higher than today at 16,000 ft. (4,877 m) before a major debris avalanche and the resulting Osceola Mudflow 5,000 years ago.

Hazard map
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Hazard map

In the past, Rainier has had large debris avalanches, and has also produced enormous lahars (volcanic mudflows) due to the large amount of glacial ice present. Its lahars have reached all the way to the Puget Sound. Around 5,000 years ago, a large chunk of the volcano slid away and that debris avalanche helped to produce the massive Osceola Mudflow, which went all the way to the site of present-day Tacoma and south Seattle. This massive avalanche of rock and ice took out the top 1,600 ft. (488 m) of Rainier, bringing its height down to around 14,400 ft. (4,389 m). About 530 to 550 years ago, the Electron Mudflow occurred, although this was not as large-scale as the Osceola Mudflow.

After the major collapse 5,000 years ago, subsequent eruptions of lava and tephra built up the modern summit cone until about as recently as 1,000 years ago. As many as 11 Holocene tephra layers have been found.

The most recent recorded volcanic eruption was between 1820 and 1854, but many eyewitnesses reported eruptive activity in 1858, 1870, 1879, 1882 and 1894 as well. As of 2002, there is no imminent risk of eruption, but geologists expect that the volcano will erupt again.

Lahars from Rainier pose the most risk to life and property, as many communities lie atop older lahar deposits. Not only is there much ice atop the volcano, the volcano is also slowly being weakened by hydrothermal activity. According to Geoff Clayton, a geologist with RH2, a repeat of the Osceola mudflow would destroy Enumclaw, Kent, Auburn, and most or all of Renton. Such a mudflow may also reach down the Duwamish estuary and destroy parts of downtown Seattle, and (speculatively) may cause tsunamis in Puget Sound and Lake Washington.

Rainier is also capable of producing pyroclastic flows as well as lava.

3,300 foot (1,000 m) high Willis Wall dominates the north face of the mountain (right center). Winthrop Glacier (left) is bounded by Steamboat Prow and Curtis Ridge.
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3,300 foot (1,000 m) high Willis Wall dominates the north face of the mountain (right centre). Winthrop Glacier (left) is bounded by Steamboat Prow and Curtis Ridge.
Descending from the summit ice cap, Tahoma Glacier is flanked by Puyallup and South Tahoma Glaciers
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Descending from the summit ice cap, Tahoma Glacier is flanked by Puyallup and South Tahoma Glaciers

Human history

Mount Rainier was first known by the Native Americans as Tah-ho-ma. At the time of European contact, the river valleys and other areas near the mountain were inhabited by many Pacific Northwest tribes who hunted and gathered berries in the forests and mountain meadows. These included the Nisqually, Cowlitz, Yakama, Puyallup, and Muckleshoot.

Captain George Vancouver reached Puget Sound in 1792 and became the first European to see the mountain. He named it in honour of his friend, Rear Admiral Peter Rainier.

In 1833, Dr. William Tolmie explored the area looking for medicinal plants. He was followed by other explorers seeking challenge. Hazard Stevens and P.B. Van Trump received a hero's welcome in the streets of Olympia after their successful summit climb in 1870. John Muir climbed Mount Rainier in 1888, and although he enjoyed the view, he conceded that it was best appreciated from below. Muir was one of many who advocated protecting the mountain. In 1893, the area was set aside as part of the Pacific Forest Reserve in order to protect its physical/economic resources: timber and watersheds.

Citing the need to also protect scenery and provide for public enjoyment, railroads and local businesses urged the creation of a national park in hopes of increased tourism. On March 2, 1899, President William McKinley established Mount Rainier National Park as America's fifth national park. Congress dedicated the new park "for the benefit and enjoyment of the people; and...for the preservation from injury or spoliation of all timber, mineral deposits, natural curiosities, or wonders within said park, and their retention in their natural condition."

View of Mount Rainier from the observation deck of the Space Needle. Liberty Cap is the visible summit from this view, sitting atop the Willis Wall, the large snow-free area.
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View of Mount Rainier from the observation deck of the Space Needle. Liberty Cap is the visible summit from this view, sitting atop the Willis Wall, the large snow-free area.

In 1998, the United States Geological Survey began putting together the Mount Rainier Volcano Lahar Warning System to assist in the emergency evacuation of the Puyallup River valley in the event of a catastrophic debris flow. It is now run by the Pierce County Department of Emergency Management. Tacoma, at the mouth of the Puyallup, is only 37 miles (60 km) west of Rainier, and moderately sized towns such as Puyallup and Orting are only 27 and 20 miles (44 and 32 km) away, respectively.

Subsidiary peaks

Mount Rainier from space
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Mount Rainier from space

The broad top of Mount Rainier contains three named summits. The highest is called Columbia Crest. The second highest summit is Point Success, 14,158 ft (4,315 m), at the southern edge of the summit plateau, atop the ridge known as Success Cleaver. It has a topographic prominence of about 138 ft (42 m), so it is not considered a separate mountain. The lowest of the three summits is Liberty Cap, 14,112 ft (4,301 m), at the northwestern edge, which overlooks Liberty Ridge, the Sunset Amphitheater, and the dramatic Willis Wall. Liberty Cap has a prominence of 492 ft (197 m), and so would qualify as a separate mountain under most strictly prominence-based rules. However it is not usually considered a separate mountain, due to the massive size of Mount Rainier, relative to which a 492 foot drop is not very large.

High on the eastern flank of Mount Rainier is a peak known as Little Tahoma, 11,138 ft (3,395 m), a volcanic remnant of an earlier configuration of Mount Rainier. It has a prominence of 858 ft (262 m), and it is almost never climbed in direct conjunction with Columbia Crest, so it is usually considered a separate mountain.

Washington state quarter

The quarter, which will be released in March or April 2007, will feature the volcano and a salmon.

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