Mount Rainier

Mount Rainier

MOUNT RAINIER is the highest mountain of the Cascade Range.  It is a large STRATO VOLCANO and is located 87 km southeast of Seattle.

It is the most topographically prominent mountain in the contiguous Us and the Cascade Volcanic Arc, with a summit of 14,411ft.  Mount Rainier is considered one of the most dangerous volcanoes in the world, and is on the DECADE VOLCANO LIST.  Because of its large amount of glacial ice, it could potentially produce massive LAHARS (volcanic mud-flows)that could threaten the entire PUYALLUP River Valley.

Mount Rainier scenery

Mount Rainier was first known as TALOL or TACOMA or TAHOMA by the Native Americans.  One hypothesis of the word origin is that TACOMA means “larger than Mount Baker”.  TA (larger) + KOMA (Mount Baker).  In 1890, the US Board of Geographic Names declared that the mountain would be known as RAINIER.

On clear days it dominates the south-eastern horizon and can be seen from as far as Portland, Oregon and Victoria British Columbia.  But on a cloudy morning, when the cloud-heights are just right, the rising sun can catch the peak from below and cast a long shadow on the underside of the cloud.  This only happens during the fall and winter when the sun rises farther to the south and is in the exact position where Mount Rainier blocks the first rays of morning light.

Mount Rainier lake

With 26 major glaciers and of permanent snowfields, Mount Rainier is the most heavily glaciated peak.  The summit is topped by two volcanic craters, each more than 1,00oft in diameter, with the larger east crater overlapping the west crater.  Geo-thermal heat from the volcano keeps areas of both craters with nearly 3.2km of passages.  A small “crater lake”, about 130 x 30ft in size and 16ft deep, the highest in North America with a surface elevation of 14,203ft, occupies the lowest portion of the west crater below more than 100ft of ice and is accessible only via the caves.

Mt Rainier sunset

The broad top of Mount Rainier contains three named summits.  The highest is called the COLUMBIA CREST, the 2nd summit is POINT SUCCESS and it has a topographic prominence of about 138ft, so it is not considered a separate peak.  The lowest of the 3 summits is LIBERTY CAP, which overlooks Liberty Bridge, the Sunset Amphitheatre and the dramatic Willis Wall.  High on the eastern flank of Mount Rainier is a peak known as LITTLE TAHOMA PEAK, an eroded remnant of the earlier, much higher, Mount Rainier.

Mount Rainier Summit Lake

Mount Rainier is a STRATO VOLCANO and its early volcanic deposits are estimated at more than 840,000 years old.  The early deposits formed a “proto-Rainier” or an “ancestral” cone.  The volcano is highly eroded with glaciers and appears to be made mostly of ANDESITE.  Many years ago, a large chunk of the volcano slid away, and this massive avalanche removed the top of Mount Rainier, bringing its height down to 14,00ft.  Subsequent eruptions of lave and TEPHRA built up the modern “summit cone” until about as recently as 1,000 years ago.

Although Mount Rainier is an a “active volcano”, as of 2010 there was no evidence of an “imminent” eruption.  However, an eruption could be devastating for all areas surrounding the volcano and there could e loss of life and property.
LAHARS  from Mount Rainier pose the most risk to life as about 150,000 people live on top of old LAHAR deposits and such lahars could cause tsunamis capable of producing PYROCLASTIC FLOWS and expelling lava.

Mount Rainier climb

The volcanic risk is somewhat mitigated by “lahar-warning signs”  and “escape route signs” in Pierce County.  5-10 “shallow” earthquakes, over 2-3 days, take place from time to time, in the region of 13,000ft below the summit., and are thought to be caused by the circulation of hot fluids beneath Mount Rainier.  SEISMIC SWARMS are common features at volcanoes and are rarely associated with eruptive activity.  A 2009 “swarm” produced the largest number of events of any swarm at Rainier, since “seismic monitoring” began over 2 decades earlier.  Yet another swarm was observed in 2011.

Mount Rainier climbing routes

Mountain climbing on Mount Rainier is difficult, involving traversing the largest glaciers in the US.  Most climbers require 2-3 days to reach the summit and climbing teams demand experience in glacier travel, self-rescue and wilderness travel.  About 8,000-13,000 people attempt the climb each year.  Mount Rainier is also popular for winter sports —– snowshoeing and cross-country skiing.

Ascending to 14,410 ft above sea level, Mount Rainier stands as an ICON in the Washington landscape.  It is the most glaciated peak spawning 6 major rivers.  Sub-alpine wildflower meadows ring the icy volcano, while ancient forest cloaks Mount Rainier’ slower slopes.  A LIFETIME OF DISCOVERY AWAITS.

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