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Kīlauea

2007 Schools Wikipedia Selection. Related subjects: Central & South American
Geography

                     Kīlauea
   3D false-colour satellite image of Kīlauea
   Elevation     4,091 ft (1,247 m)
   Location      Hawaiʻi, USA
   Range         Hawaiian Islands
   Coordinates   19°25′N 155°17′W
   Type          Shield volcano
   Age of rock   < 23000 yrs
   Last eruption 2006 (continuing)

   Kīlauea is an active volcano in the Hawaiian Islands, one of five
   shield volcanoes that together form the Island of Hawaiʻi. In Hawaiian,
   the word kīlauea means "spewing" or "much spreading", in reference to
   the mountain's frequent outpouring of lava. It is presently the most
   active volcano and one of the most visited active volcanoes on the
   planet. Kīlauea is just the most recent of a long series of volcanoes
   that created the Hawaiian Archipelago, as the Pacific Plate moves over
   a more or less fixed hotspot in the Earth's mantle (see, however,
   Lōʻihi).

Description

   Kīlauea's absolute location is 19.452 North, 155.292 West. It lies
   against the southeast flank of much larger Mauna Loa volcano. Mauna
   Loa's massive size and elevation (13,677 feet or 4,169 m) is a stark
   contrast to Kīlauea, which rises only 4,091 feet (1,247 m) above sea
   level, and thus from the summit caldera appears as a broad shelf of
   uplands well beneath the long profile of occasionally snow-capped Mauna
   Loa, 15 miles (24 km) distant.

   First-time visitors to Kīlauea, not familiar with how different the
   profile of a shield volcano can be compared with stratovolcanoes like
   Mt. Fuji, Mount Hood, and Mount St. Helens, are usually unaware they
   are approaching the summit of an active volcano as they make the drive
   up through the cloud forest on State Rte. 11 to Hawaiʻi Volcanoes
   National Park from Hilo—or coming from Kailua-Kona via South Point
   across the Kaʻū Desert. From Hilo, the highway heads south to Keaʻau,
   then turns abruptly westward to begin the climb to the Kīlauea caldera.
   For some 20 miles (32 km) the road runs relatively straight, making a
   4,000 ft (1,200 m) ascent. However, most of this climb is actually on
   the heavily vegetated flank of Mauna Loa; the crossing onto lava flows
   issued from Kīlauea is about 1 mile west of Glenwood, 18 miles (29 km)
   from Hilo. The Mauna Loa flows are several thousand years old; the
   lightly vegetated Kīlauea flows are only 350 to 500 years old.
   Glowing ʻaʻā flow front advancing over pāhoehoe on the coastal plain of
   Kīlauea in Hawaiʻi.
   Enlarge
   Glowing ʻaʻā flow front advancing over pāhoehoe on the coastal plain of
   Kīlauea in Hawaiʻi.

   Driving from the Kona Coast, the immense size of the Big Island becomes
   apparent: from Kailua-Kona it is 98 miles (158 km) on the Māmalahoa
   Highway (State Rte. 11) to Kīlauea. After passing around the southern
   end of Mauna Loa, the highway turns northeastward towards Kīlauea once
   past the town of Nāʻālehu. Yet, as from the Hilo side, the long climb
   from near sea level to the summit is all on the flank of Mauna Loa. Not
   until the Sulfur Bank scarp (the northwestern edge of Kīlauea Caldera),
   near the intersection of Crater Rim Drive in Hawaiʻi Volcanoes National
   Park, does the road cross over onto Kīlauea. However, the highway
   parallels the line of contact between the two volcanoes—always less
   than 1 mile to the southeast—from the vicinity of Punaluʻu at the coast
   to the caldera at the summit.

Kaʻū

   The highway route from the west (State Rte. 11) is vastly different
   from that seen when coming from Hilo. The highway approaches Kīlauea
   through a desert on the leeward slope called Kaʻū. Kīlauea's height of
   4000 ft is sufficient to force most of the moisture out of the
   impinging Northeast Trades, leaving Kaʻū in the rain shadow of the
   "low" mountain. This area is also the very active southwest rift zone
   of Kīlauea, a prolific ash producer. Winds redistribute the ash,
   causing dust storms and forming dunes across a landscape barren of most
   vegetation.
   A view of Puʻu Ōʻō's crater
   Enlarge
   A view of Puʻu Ōʻō's crater

Kīlauea Caldera and Halemaʻumaʻu Crater

   Halemaʻumaʻu crater
   Enlarge
   Halemaʻumaʻu crater

   Hawaiʻi Volcanoes National Park encompasses a portion of Kīlauea, and
   the park visitor centre is located near the margin of the summit
   caldera, overlooking a large pit crater called Halemaʻumaʻu. The
   roughly circular caldera measures 3x5 km (or 6x6 km, including the
   outermost ring faults).

Kīlauea eruptions

   Steam plume as Kīlauea lava enters the ocean
   Enlarge
   Steam plume as Kīlauea lava enters the ocean

   Eruptions at Kīlauea occur primarily either from the summit caldera or
   along either of the lengthy East and Southwest rift zones that extend
   from the caldera to the sea. In recent decades, eruptions have been
   continuous, with many of the lava flows reaching to the Pacific Ocean
   shore. About 90% of the surface of Kīlauea is lava flows less than
   1,100 years old; 70% of the surface is younger than 600 years.

   There were forty-five separate eruptions of Kīlauea in the twentieth
   century. The Mauna Ulu eruption of Kīlauea began on May 24, 1969 and
   ended on July 22, 1974. At the time, Mauna Ulu was the longest flank
   eruption of any Hawaiian volcano in recorded history. The eruption
   created a new vent, covered massive amounts of land with lava, and
   added new land to the island.

   The Mauna Ulu eruption first started as a fissure between two pit
   craters, ʻĀloʻi and ʻAlae, where the Mauna Ulu shield would eventually
   form. Both pāhoehoe and ʻaʻā lava erupted from the volcano. Early on,
   fountains of lava burst out as much as 540 meters high. In early 1973,
   an earthquake occurred that caused Kīlauea to stop erupting near the
   original Mauna Ulu site and instead erupt near the craters Pauahi and
   Hiʻiaka. However, the eruption site soon returned to normal.

   The current Kīlauea eruption began in January 1983 along the East rift
   zone from Puʻu ʻŌʻō-Kūpaʻianahā and continues to produce lava flows
   that travel 11 to 12 km from these vents to the sea. This eruption has
   covered over 104 km² of land on the southern flank of Kīlauea and has
   built out into the sea 2 km² of new land. Since 1983 more than 1.9 km³
   of lava has been erupted, making the 1983-to-present eruption the
   largest historically known for Kīlauea. In fact in the early to middle
   1980s Kīlauea was known as "The Drive-by Volcano" because anyone could
   ride by and see the lava fountains (some as much as 1000 feet in the
   air) from their car. The lava fountains are a great backdrop in the
   movie "Black Widow" made in 1985.

   The 1990 lava flow in particular was notable for being destructive of
   property. In the 1990 lava flow the towns of Kalapana and Kaimū were
   totally destroyed, as were Kaimū Bay, Kalapana Black Sand Beach, and a
   large section of State Rte. 130, which now abruptly dead-ends at the
   lava flow.

   While Kīlauea is justly known for its largely non-explosive eruptions,
   it has a darker side to it: it has had large explosive eruptions in the
   past . The most recent of such explosive eruptions occurred in 1924,
   when magma interacted with groundwater as the long-standing lava lake
   in Halemaʻumaʻu Crater drained. Even larger ones have occurred,
   including one in 1790, which killed at least several dozen people.
   Eruption columns are inferred to have gone at least as high as 9 km
   (5.6 miles) and even up to 15-20 km (9-12 miles) in altitude — much
   higher than the cruising altitude of airliners.

   Eruptions from Kīlauea also are known for creating vog, or volcanic
   smog, which affects many areas of the Hawaiian Islands, including Oʻahu
   and Honolulu whenever winds come out of the south or southeast.

Pele

   Kīlauea is considered to be the present home of Pele, the volcano
   goddess of ancient Hawaiian legend. Several special lava formations are
   named after her, including Pele's Tears (small droplets of lava that
   cool in the air and retain their teardrop shapes) and Pele's Hair
   (thin, brittle strands of volcanic glass that often form during the
   explosions that accompany a lava flow as it enters the ocean).

   In Hawaiian mythology, Kīlauea is the location around where most of the
   conflict between Pele and the rain god Kamapuaʻa took place.
   Halemaʻumaʻu, "House of the ʻamaʻumaʻu fern", derives its name from the
   final struggle between the two gods: being the favorite residence of
   Pele, Kamapuaʻa, hard-pressed by Pele's ability to make lava spout from
   the ground at will, covered it with the fronds of the fern. Choking
   from the smoke which could not escape anymore, Pele emerged. Realizing
   that each could threaten the other with destruction, the gods had to
   call their fight a draw and divided the island among them: Kamapuaʻa
   received the windward northeastern side, and Pele ruled over the drier
   Kona (" leeward") side. The rusty, singed appearance of the young
   fronds of the ʻamaʻumaʻu was said to be a product of the legendary
   struggle.

   Retrieved from " http://en.wikipedia.org/wiki/K%C4%ABlauea"
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