Kilauea Volcano, Hawaii

Photo Courtesy In.com

The Islands of Hawaii are constructed from five individual shield volcanoes that erupted, for the most part 'in order' one overlapping another. From oldest to youngest these are:

**Kohala (extinct)
**Mauna Kea (dormant)
**Hualalai (dormant)
**Mauna Loa (active)
**Kilauea (very active)

Kilauea can be found on the Big Island of Hawaii. It pushes up against the southeast portion of themuch larger Mauna Loa volcano. Mauna Loa's huge size and elevation (13,677 feet) is in contrast to Kilauea, which is only 4,091 feet above sea level, and ergo from its summit appears as a broad shelf of land far beneath the long profile of occasionally snow topped Mauna Loa, 15 miles away. Kilauea is a very low and flat shield volcano, which is quite different in profile from the high, sharply sloping peaks of volcanoes such as Mount St. Helens and Mount Hood.

Eruptions at Kilauea generally occur either from the collapsed summit or along either of the long East and Southwest rift areas that extend from the summit and run roughly parallel to the island's coastline. Recently, eruptions have been virtually continuous, with many of the lava flows reaching the Pacific. Roughly 90% of the surface of Kilauea made up of lava flows less than 1,100 years old, with 70% of the surface less than 600 years of age.

There have been 45 eruptions of Kilauea in the 20th century. The Mauna Ulu eruption of Kilauea began on May 24, 1969 and stopped on July 22, 1974. At the time, Mauna Ulu was the unquestionably the longest flank eruption of any Hawaiian volcano ever recorded. This eruption formed a new vent that covered huge amounts of land with lava, and added new land to the island. The Mauna Ulu eruption first started as a fissure between two craters where the Mauna Ulu shield would form. Initially, fountains of lava burst out as much as 1772 ft high. In 1973, an earthquake occurred that caused Kilauea to quit erupting near the original Mauna Ulu site and instead erupted near the craters Pauahi and Hiiaka. However, the eruption site soon returned to its normal flow. The 1990 lava flow was notable for its destruction of property.

Around 2 A.M. on March 19, 2008, Halemaumau saw its first explosive episode since 1924, and the first eruption in the caldera since 1982. A steam vent that had just recently opened in area violently exploded, setting off a magnitude 3.7 earthquake, throwing rocks over a 75 acre region. A small amount of ash was also seen in a nearby town. The explosion debris covered part of Crater Rim Drive and damaged Halemaumau overlook. The explosion did not spew lava, which tells scientists that it was caused by hydrothermal or gas sources.

The explosion came after increased sulfur dioxide levels from the crater. The serious increase of sulfur dioxide gas caused closures of many roads and hiking trails namely; Crater Rim Drive, Chain of Craters Road, and the Crater Rim Trail from Kilauea Military Camp to Chain of Craters Road, and all hiking trails leading to the crater, including those from Byron Ledge, Sandalwood Trail, and the Kau Desert Trail.

Just before dawn on March 24, 2008, white gas ejection changed to brown-gray ash, and lava particles were thrown from the vent, forming Pele's Hair, Pele's Tears, and 4-inch lava spatters around the vent. This is the first time fresh lava has been thrown in the crater since 1982.