Crater Lake National Park
From Wikipedia, the free
encyclopedia
Jump to: navigation,
search
Crater
Lake National Park
|
|
IUCN
category II (national park)
|
|
Location
of Crater Lake in southwestern Oregon
|
|
Location
|
southwestern Oregon, United
States
|
Nearest city
|
|
Coordinates
|
|
Area
|
183,225 acres (74,149 ha)[1]
|
Established
|
May 22, 1902
|
Visitors
|
423,551 (in 2011)[2]
|
Governing body
|
|
Crater Lake
National Park is a United States National Park located in southern
Oregon. Established in 1902, Crater Lake National Park is the fifth oldest
national park in the United States and the only one in the state of Oregon.[3]
The park encompasses the caldera of Crater Lake, a remnant of a destroyed volcano, Mount
Mazama, and the surrounding hills and forests.
The lake is
1,943 feet (592 m) deep at its deepest point,[4]
which makes it the deepest lake in the United States, the second deepest in
North America and the ninth deepest in the world.[4]
Crater Lake is often referred to as the seventh deepest lake in the world, but
this former listing excludes the approximately 3,000-foot (910 m) depth of
subglacial Lake Vostok in Antarctica, which resides under nearly
13,000 feet (4,000 m) of ice, and the recent report of a 2,740-foot
(840 m) maximum depth for Lake
O'Higgins/San Martin, located on the border of Chile and Argentina.
However, when comparing its average depth of 1,148 feet (350 m) to the
average depth of other deep lakes, Crater Lake becomes the deepest in the
Western Hemisphere and the third deepest in the world. The impressive average
depth of this volcanic lake is due to the nearly symmetrical 4,000-foot
(1,200 m) deep caldera formed 7,700 years ago during the violent climactic
eruptions and subsequent collapse of Mount Mazama and the relatively moist
climate that is typical of the crest of the Cascade
Range.
The caldera rim
ranges in elevation from 7,000 to 8,000 feet (2,100 to 2,400 m). The United States Geological Survey
benchmarked elevation of the lake surface itself is 6,178 feet (1,883 m).
This National Park encompasses 183,225 acres (286.29 sq mi;
741.49 km2).[1]
Crater Lake has no streams flowing into or out of it. All water that enters the
lake is eventually lost from evaporation or subsurface seepage. The lake's
water commonly has a striking blue hue, and the lake is re-filled entirely from
direct precipitation in the form of snow and rain.
Contents
|
Geology
For more
details on this topic, see Mount Mazama.
Relief map of
the Crater Lake area
Volcanic
activity in this area is fed by subduction
off the coast of Oregon as the Juan de Fuca Plate slips below the North American Plate (see plate
tectonics). Heat and compression generated by this movement has created a mountain
chain topped by a series of volcanoes, which together are called the Cascade
Range. The large volcanoes in the range are called the High Cascades.
However, there are many other volcanoes in the range as well, most of which are
much smaller.
About 400,000
years ago, Mount Mazama began its existence in much the same way
as the other mountains of the High Cascades, as overlapping shield
volcanoes. Over time, alternating layers of lava flows and pyroclastic
flows built Mazama's overlapping cones until it reached about 11,000 feet
(3,400 m) in height.
As the young stratovolcano
grew, many smaller volcanoes and volcanic vents were built in the area of the
park and just outside what are now the park's borders. Chief among these were cinder cones. Although the early examples are
gone—cinder cones erode
easily—there are at least 13 much younger cinder cones in the park, and at
least another 11 or so outside its borders, that still retain their distinctive
cinder cone appearance. There continues to be debate as to whether these minor
volcanoes and vents were parasitic to Mazama's magma
chamber and system or if they were related to background Oregon Cascade
volcanism.
After a period
of dormancy, Mazama became active again. Then, around 5700 BC, Mazama collapsed
into itself during a tremendous volcanic
eruption, losing 2,500 to 3,500 feet (760 to 1,100 m) in height. The
eruption formed a large caldera that, depending on the prevailing climate, was filled
in about 740 years, forming a beautiful lake with a deep blue hue, known today
as Crater
Lake.[5]
The eruptive
period that decapitated Mazama also laid waste to much of the greater Crater
Lake area and deposited ash as far east as the northwest corner of what is now
Yellowstone National Park, as far south
as central Nevada,
and as far north as southern British
Columbia. It produced more than 150 times as much ash as the May 18, 1980 eruption of Mount St. Helens.
This ash has
since developed a soil
type called andisol.
Soils in Crater Lake National Park are brown, dark brown or dark grayish brown
sandy loams or loamy sands which have plentiful cobbles, gravel and stones.
They are slightly to moderately acidic and their drainage is somewhat excessive
or excessive.
Climate
Snow is
relatively rare at low elevations in western Oregon, but it is common at higher
elevations, especially at Crater Lake. Measurements at park headquarters, 6,475
feet (1,974 m) above sea level, show that snow falls more often here than
at any other long-term weather station in Oregon. Winter, which typically begins
at the park in September and runs through June, includes an average of 98 days
with measurable snowfall. Up to 37 inches (94 cm) of snow have fallen on
the park in a single day (in 1937, 1951, and 1971), 313 inches (800 cm) in
a month (January 1950), and 903 inches (2,290 cm) in a year (1950).[6]
Snow typically
accumulates in the park to depths of 10 to 15 feet (3.0 to 4.6 m) by early
spring. Most of the park's roads remain closed through late spring, and snow
lingers into the summer. In July and August, snowfall is uncommon, and
"one magnificent day typically follows another".[7]
January is the
coldest month, when highs average about 35 °F (2 °C) and lows average
about 18 °F (−8 °C).[8]
August is the warmest month, with an average high of roughly 69 °F (21 °C)
and an average low of about 40 °F (4 °C).[8]
Between 1962 and 1990, the highest recorded temperature was 90 °F (32 °C),
and the lowest was −21 °F (−29 °C).[9]
Annual precipitation averages about 66 inches (1,700 mm) a year.[10]
December is the wettest, averaging about 11 inches (280 mm).[10]
[hide]Climate
data for Crater Lake (1981–2010 normals)
|
|||||||||||||
Month
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Jun
|
Jul
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
Year
|
Average
high °F (°C)
|
34.6
(1.4) |
35.1
(1.7) |
37.5
(3.1) |
41.7
(5.4) |
49.4
(9.7) |
57.9
(14.4) |
68.8
(20.4) |
69.7
(20.9) |
63.2
(17.3) |
52.1
(11.2) |
38.2
(3.4) |
34.0
(1.1) |
48.52
(9.18) |
Average
low °F (°C)
|
19.0
(−7.2) |
18.5
(−7.5) |
19.8
(−6.8) |
23.0
(−5.0) |
28.3
(−2.1) |
33.3
(0.7) |
40.5
(4.7) |
40.6
(4.8) |
36.2
(2.3) |
30.1
(−1.1) |
22.6
(−5.2) |
18.8
(−7.3) |
27.56
(−2.47) |
Precipitation inches (mm)
|
9.32
(236.7) |
7.75
(196.9) |
7.48
(190) |
5.37
(136.4) |
3.55
(90.2) |
2.22
(56.4) |
1.02
(25.9) |
1.00
(25.4) |
1.85
(47) |
4.44
(112.8) |
10.29
(261.4) |
11.41
(289.8) |
65.7
(1,668.8) |
Snowfall
inches (cm)
|
85.5
(217.2) |
73.8
(187.5) |
73.4
(186.4) |
48.8
(124) |
17.4
(44.2) |
4.1
(10.4) |
0.2
(0.5) |
0
(0) |
3.1
(7.9) |
17.3
(43.9) |
71.1
(180.6) |
92.7
(235.5) |
487.4
(1,238) |
Avg.
precipitation days (≥ 0.01 in)
|
17.9
|
15.9
|
18.1
|
15.5
|
11.2
|
8.1
|
3.9
|
4.0
|
5.8
|
9.8
|
17.5
|
18.0
|
145.7
|
Avg.
snowy days (≥ 0.1 in)
|
15.9
|
14.3
|
16.1
|
12.6
|
6.0
|
2.0
|
0.2
|
0.1
|
1.0
|
4.7
|
13.2
|
16.4
|
102.5
|
Source:
NOAA [11]
|
|||||||||||||
Park features
The Pinnacles
Some notable
park features created by this huge eruption are:
- The Pumice Desert: A very thick layer of pumice and ash leading away from Mazama in a northerly direction. Even after thousands of years, this area is largely devoid of plants due to excessive porosity (meaning water drains through quickly) and poor soil composed primarily of regolith.
- The Pinnacles: When the very hot ash and pumice came to rest near the volcano, it formed 200-to-300-foot (60 to 90 m) thick gas-charged deposits. For perhaps years afterward, hot gas moved to the surface and slowly cemented ash and pumice together in channels and escaped through fumaroles. Erosion later removed most of the surrounding loose ash and pumice, leaving tall pinnacles and spires.
Other park
features
- Mount Scott is a steep andesitic cone whose lava came from magma from Mazama's magma chamber; geologists call such volcano a parasitic or satellite cone. Volcanic eruptions apparently ceased on Scott sometime before the end of the Pleistocene; one remaining large cirque on Scott's northwest side was left unmodified by post-ice age volcanism.
- In the southwest corner of the park stands Union Peak, an extinct volcano whose primary remains consist of a large volcanic plug, which is lava that solidified in the volcano's neck.
- Crater Peak is a shield volcano primarily made of andesite and basalt lava flows topped by andesitic and dacite tephra.
- Timber Crater is a shield volcano located in the northeast corner of the park. Like Crater Peak, it is made of basaltic and andesitic lava flows, but, unlike Crater, it is topped by two cinder cones.
- Rim Drive is the most popular road in the park; it follows a scenic route around the caldera rim.
- Llao Rock on the north side rises 1,800 feet (550 m) above the lake, with a 1.3-mile (2.1 km) trail from Rim Drive leading to the summit.[12]
- The Pacific Crest Trail, a 2,650-mile (4,260 km) long distance hiking and equestrian trail that stretches from the Mexican to Canadian borders, passes through the park.
- Old-growth forests covering 50,000 acres (20,000 ha).[13]
180-degree
panoramic photograph of Crater Lake from the top of nearby Mount Scott, looking west. Two
snow-covered peaks can be seen in the distance: to the right of the lake is Mount
Thielsen, and in the far left of the photo is Mount
McLoughlin.
History
Aerial view of
Crater Lake
Local Native Americans witnessed the collapse of Mount
Mazama and kept the event alive in their legends. One
ancient legend of the Klamath people closely parallels the geologic story
which emerges from today's scientific research. The legend tells of two Chiefs,
Llao of the Below
World and Skell of
the Above World, pitted in a battle which ended up in the destruction of Llao's
home, Mt. Mazama.[14]
The battle was witnessed in the eruption of Mt. Mazama and the creation of
Crater Lake.
A trio of gold prospectors: John Wesley Hillman, Henry Klippel, and Isaac
Skeeters were the first whites to visit the lake. On June 12, 1853, they
stumbled upon the long, sloping mountain while hunting for provisions. Stunned
by vibrant blue color of the lake, they named the indigo body of
water "Deep Blue Lake" and the place on the southwest side of the rim
where he first saw the lake later became known as Discovery Point.[3]
But gold was more on the minds of settlers at the time and the discovery was
soon forgotten. The suggested name later fell out of favor by locals, who
preferred the name Crater Lake.
William Gladstone Steel devoted his life
and fortune to the establishment and management of a National Park at Crater
Lake. His preoccupation with the lake began in 1870. In his efforts to bring
recognition to the park, he participated in lake surveys that provided
scientific support. He named many of the lake's landmarks, including Wizard
Island, Llao Rock, and Skell Head.
With the help
of geologist Clarence Dutton, Steel organized a USGS expedition to study the
lake in 1886. The party carried the Cleetwood, a half-ton survey boat,
up the steep slopes of the mountain then lowered it to the lake. From the stern
of the Cleetwood, a piece of pipe on the end of a spool of piano wire
sounded the depth of the lake at 168 different points. Their deepest sounding,
1,996 feet (608 m), was very close to the modern official depth of 1,932
feet (589 m) made in 1953 by sonar.[3]
At the same time, a topographer surveyed the area and created the first
professional map of
the Crater Lake area.
Partly based on
data from the expedition and lobbying from Steel and others, Crater Lake
National Park was established May 22, 1902 by President Theodore Roosevelt. And because of Steel's
involvement, Crater Lake Lodge was opened in 1915 and the Rim
Drive was completed in 1918.[3]
Highways were
later built to the park to help facilitate tourism. The 1929 edition of O Ranger! described access and
facilities available by then:
Crater Lake
National Park is reached by train on the Southern Pacific Railroad lines into Medford
and Klamath Falls, at which stops motor stages make the
short trip to the park. A hotel on the rim of the lake offers accommodations.
For the motorist, the visit to the park is a short side trip from the Pacific and Dalles-California highways. He will
find, in addition to the hotel, campsites, stores, filling
stations. The park is open to travel from late June or July 1 for as long
as snow does not block the roads, generally until October.[15]
Although snow
covers Crater Lake National Park for eight months of the year (average annual
snowfall is 533 in (1,350 cm)), the lake rarely freezes over due in
part to a relatively mild onshore flow from the Pacific
Ocean. The last recorded year in which the lake froze over was in 1949, a
very long, cold winter. A 95% surface freeze occurred in 1985. The immense
depth of Crater Lake acts as a heat reservoir that absorbs and traps sunlight,
maintaining the lake temperature at an average of 55 °F (12.8 °C) on the
surface and 38 °F (3.3 °C) at the bottom throughout the year. The surface
temperature fluctuates a bit, but the bottom temperature remains quite
constant.
Activities
Daily Trips
(1931)
There are many hiking trails
inside the park, and several campgrounds. Unlicensed fishing is allowed without
any limitation of size, species, or number. The lake is believed to have no
indigenous fish, but several species of fish were introduced beginning in 1888
until all fish stocking ended in 1941. Kokanee
Salmon (Oncorhynchus nerka) and Rainbow
Trout (Oncorhynchus mykiss) now thrive and reproduce here naturally.[16]
Swimming is allowed in the lake, and the boat tours, which stop at Wizard
Island a cinder cone inside the lake, operate daily during the summer. All
lake access for people is from Cleetwood Trail, a steep walking trail, and
there are no roads for cars, trucks, or wagons that lead to the waterfront. All
of the boats in the lake were delivered by helicopter.[17]
Numerous
observation points along the caldera rim for the lake are readily accessible by
automobile
via the "Rim Drive", which is 33 miles (53 km) long and has an
elevation gain of 3,800 feet (1,200 m).
The highest
point in Crater Lake National Park is Mt. Scott at 8,929 feet
(2,722 m). Getting there requires a fairly steep 2.5-mile (4.0 km)
hike from the Rim Drive trailhead. On a clear day visibility from the summit
exceeds 100 miles (160 km), and one can, in a single view, take in the entire
caldera. Also visible from this point are the white-peaked Cascade
Range volcanoes
to the north, the Columbia River Plateau to the east, and also
the Western Cascades and the more-distant Klamath
Mountains to the west.
The scenery of
Crater Lake is fully accessible during the summer months. Heavy snowfalls in
this park during the fall, winter, and spring months force many road and trail
closures, including the popular "Rim Drive", which is generally
completely open from July to October, and partially open in some other months,
such as May, June, and November.