- Hawaiian eruption
A Hawaiian eruption is a type of
volcanic eruptionwhere lavaflows from the vent in a relative gentle, low level eruption, so called because it is characteristic of Hawaiian volcanoes. Typically they are effusive eruptions, with basaltic magmas of low viscosity, low content of gases, and high temperature at the vent. Very little amount of volcanic ashis produced. This type of eruption occurs most often on hotspot volcanoes such as Kilauea, though it can occur near subduction zones (e.g. Medicine Lake, California.) Another example of Hawaiian eruptions occurred on Surtseyfrom 1964 to 1967, when molten lava flowed from the crater to the sea.
Hawaiian eruptions may occur along
fissure vents, such as during the eruption of Mauna Loa Volcanoin 1950, or at a central vent, such as during the 1959 eruption in Kilauea Iki Crater, which created a lava fountain 580 meters (1,900 ft) high and formed a 38 meter cone named Puu Puai. In fissure-type eruptions, lava spurts from a fissure on the volcano's rift zoneand feeds lava streams that flow downslope. In central-vent eruptions, a fountain of lava can spurt to a height of 300 meters or more (heights of 1600 meters were reported for the 1986 eruption of Mount Miharaon Izu Ōshima, Japan).
Hawaiian eruptions usually start by formation of a crack in the ground from which a curtain of incandescent
magmaor several closely spaced magma fountains appear. The lava can overflow the fissure and form aa or pahoehoe style of flows. Eruptions from a central cone can form small lightly sloped shield volcanoes, for example the Mauna Loa.
Petrology of Hawaiian Basalts
The key factors in generating a Hawaiian eruption are basaltic magma and a low percentage of dissolved water (less than one percent). The lower the water content, the more peaceful is the resulting flow. Almost all lava that comes from Hawaiian volcanoes is
basaltin composition. Hawaiian basalts that make up almost all of the islands are tholeiite. These rocks are similar but not identical to those that are produced at ocean ridges. Basalt relative richer in sodium and potassium (more alkaline) has erupted at the undersea volcano of Loihiat the extreme southeastern end of the volcanic chain, and these rocks may be typical of early stages in the "evolution" of all Hawaiian islands. In the late stages of eruption of individual volcanoes, more alkaline basalt also was erupted, and in the very late stages after a period of erosion, rocks of unusual composition such as nephelinitewere produced in very small amounts. These variations in magma composition have been investigated in great detail, in part to try to understand how mantle plumes may work.
Hawaiian eruptions are usually the most attractive to
touristsand are the safest because there is little danger from ash. However, Hawaiian eruptions are not always safe.
In 1790, 80 warriors marching on Kilauea were killed in an eruption.cite book|title=Natural Hazards of North America|format=map|publisher=
National Geographic Society] On May 18, 1924, an plantation accountant named Truman Taylor who was sightseeing on Kilauea's caldera, was hit with debris from an explosion.cite book|author=William Melson|page=123|title=Volcano|publisher=Time Life Books|id=ISBN 0-8094-4304-X|year=1982] Although rushed to hospital, Taylor succumbed to his injuries later that day.cite web|title=The 1924 Explosions of Kilauea|url=http://hvo.wr.usgs.gov/kilauea/history/1924May18/|publisher= Hawaiian Volcano Observatory|accessdate=2008-03-19]
last = Frankel
first = Charles
title = Worlds on Fire: Volcanoes on the Earth, the Moon, Mars, Venus and Io
Cambridge University Press
date = 2005
pages = 21-22
isbn = 0521803934
last = Frankel
first = Charles
title = Volcanoes of the Solar System
Cambridge University Press
date = 1996
pages = 17
isbn = 0521477700
last = Casadevall
first = T.J. (ed.)
title = Volcanic Ash and Aviation Safety: Proceedings of the First International Symposium on Volcanic Ash and Aviation Safety
publisher = DIANE Publishing
date = 1995
pages = 437
isbn = 0788116509
last = MacDonald
first = Gordon A.
last2 = Peterson
first2 = Frank L.
last3 = Abbott
first3 = Agatin T.
title = Volcanoes in the Sea: Geology of Hawaii (2nd edition)
University of Hawaii Press
date = 1983
pages = 156-157
isbn = 0824808320
* [http://hvo.wr.usgs.gov/ Hawaii Volcano Observatory]
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