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Of the 20 highest peaks in the United States, 17 are in Alaska. Mt. McKinley,
the highest peak in North America, is 20,320 ft. above sea level. Denali, the
Indian name for the peak, means "The Great One." The forces that
lifted Mount McKinley is the subduction of the Pacific plate
beneath the North American plate.. This plate also raised great
ranges across southern Alaska. As that huge sheet of ocean-floor
rock plunges downward into the mantle, it shoves and crumples
the continent into soaring mountains which include some of the
most active volcanoes on the continent. Mount McKinley in
particular is uplifted relative to the rocks around it because
it is at the intersection of major active strike-slip faults
(faults that move rocks laterally across the Earth's surface)
which allow the deep buried rocks to be unroofed more rapidly
compared to those around them.
Mt. McKinley, or Mt. Denali, is much taller than Mt. Everest.
In fact, Denali is one of the most massive mountains in the
world. Mt. McKinley has been the goal of aspiring high
altitude climbers since it was first climbed in 1913. Its
reputation as a highly coveted summit derives from its location
near the Arctic Circle and the Pacific Ocean giving it some of
the most ferocious weather in the world.
In the south and southeast, the Pacific Mountain system is a
major feature and is divided into many subdivisions. The Chugach Mountains begin near the Alaskan panhandle and form the coast along
much of Southcentral Alaska. These mountains contain the greatest concentration
of glacial ice in Alaska. As the warm, moist winter air off the ocean meets
these mountains and cools, it creates some of the highest snowfall in Alaska.
During the winter of 1952-1953, Thompson Pass near Valdez received about 81 feet
(25 meters) of snow. A major fault in Prince William Sound is contributing to the ongoing formation
of these mountains. In 1964, this fault slipped, creating the Good Friday
Earthquake that severely damaged Anchorage and destroyed several smaller
communities including Chenega, Seward, and Valdez.
The Kenai Mountains cover all but the northern and western portions of the Kenai
Peninsula. Many glacier-carved lakes dot the Kenai Peninsula, including Kenai
Lake, Upper Russian Lake, and Trail Lakes. Many recreational hiking trails cut
through the Kenai Mountains.A popular attraction in the Kenai Mountians is the fjords created where the east
coast of the Kenai Peninsula meets Prince William Sound.
The Alaska Range is perhaps the most well-known mountain range
in Alaska. It is home to Denali National Park and Mt. McKinley.
This mountain range is one of Alaska's largest, starting at
Alaska's eastern border with Canada, arcing across the north of
Southcentral Alaska, ending to the west of the Kenai Peninsula.
The Alaskan Range is still changing. Spurr, an active volcano
west of Anchorage erupted in 1992 and covered Anchorage with a
thin layer of ash. On November 3, 2002, a massive 7.9 earthquake
was caused by a fault running through the Alaska Range. For
several weeks afterwards, thousands of aftershocks were
recorded. Due to Alaska's sparse population, earthquake damage
was only about $20 million.
Extending southwest from the southern Alaska mainland and the
Alaska Range, the Alaska Peninsula and the Aleutian Islands are
supported by the Aleutian Mountain Range. The Aleutian Range
extends 1,600 mile, from Mount Spurr, across Cook Inlet from Anchorage, to Attu Island
near the Asian continent and contains many active volcanoes. Collision between
continental plates has created a 1,400 mile (2,253 km) chain of
active volcanoes in this mountain range. This range is home
to the Valley of Ten Thousand Smokes, created when Novarupta erupted in 1912.
The Valley of Ten Thousand Smokes was named for the numerous fumaroles in the
area. Fumaroles are holes in the earth that release hot gas steam into the air.
North of the Central Uplands and Lowlands area is the Rocky
Mountain System of Alaska. This area is comprised of the Brooks
Range and the Brooks Range foothills. The Brooks Range is
Alaska's northernmost mountain range, all of it being located
above the arctic circle. This range stretches about 720 miles
(1,159 km) from Alaska's eastern border with Canada to the
Chukchi Sea off Alaska's west coast. Despite their northerly
location and cool temperatures, there are few glaciers in this
mountain range; this area is rather arid so not enough snow
falls during the winter to create large glaciers. The largest
glaciers in the Brooks Range aren't much longer than file miles
Arrigetch Peaks, considered by many to be the most dramatic
peaks of the western Brooks Range, perhaps the most dramatic in
all of Alaska.
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