潜水蒸气喷发
![](http://images.weserv.nl/?url=//upload.wikimedia.org/wikipedia/commons/thumb/7/71/Phreatic_Eruption-numbers.svg/220px-Phreatic_Eruption-numbers.svg.png)
![](http://images.weserv.nl/?url=//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Phreatic_St._Helens.jpg/170px-Phreatic_St._Helens.jpg)
潜水蒸气喷发(英语:phreatic eruption) 是一种蒸汽火山喷发[1] 。当岩浆喷出时遇到地下水或地表水,并被极高的岩浆温度(从500到1,170C(930到2,100F))瞬间加热为蒸汽,其将导致蒸汽、水、火山灰、岩石和火山弹等一起爆发[2]。在华盛顿州的圣海伦斯山1980年普林尼式火山喷发发前,其发生了数百次蒸汽爆发[2]。若岩浆温度不高,潜水蒸气喷发可能会导致泥火山。
潜水蒸气喷发通常包括蒸汽和岩石碎片,且液态熔岩很少。岩石碎片的温度可以是冰冷,也可以是炽热。如果有熔融岩浆一起喷发,火山学家会将该事件归类为准岩浆型火山喷发。这种喷发偶尔会形成称为低平火山口的宽阔低地形火山口。潜水蒸气喷发常排放二氧化碳或硫化氢气体。这对人体是有害的,因为足够浓度的二氧化碳能造成窒息,而硫化氢是一种毒物。例子如1979年爪哇岛的一次潜水蒸气喷发,其造成140人死亡,其中大多数人是由于气体中毒[3]。
参考文献
- ^ Mullineaux, D.R. et al. (1987) Volcanic Hazards in the Hawaiian Islands in Volcanism in Hawaii, volume 1, USGS Professional Paper 1350, page 602
- ^ 2.0 2.1 VHP Photo Glossary: Phreatic eruption". Volcano Hazards Program. U.S. Geological Survey. Retrieved 13 November 2010.
- ^ On February 20th, 1979, 142 inhabitants of Dieng Plateau (Indonesia) were asphyxiated by poisonous gases during a mild phreatic eruption. From later fields gas collection and analysis, the casualties are considered to be due to CO2 rich volcanic gases." F. Le Guern, H. Tazieff and R. Faivre Pierret, "An example of health hazard: People killed by gas during a phreatic eruption: Diëng plateau (Java, Indonesia), February 20th 1979", Bulletin of Volcanology 45 (1982): 153–156.
|