潛水蒸氣噴發
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潛水蒸氣噴發(英語:phreatic eruption) 是一種蒸汽火山噴發[1] 。當岩漿噴出時遇到地下水或地表水,並被極高的岩漿溫度(從500到1,170C(930到2,100F))瞬間加熱為蒸汽,其將導致蒸汽、水、火山灰、岩石和火山彈等一起爆發[2]。在華盛頓州的聖海倫斯山1980年普林尼式火山噴發發前,其發生了數百次蒸汽爆發[2]。若岩漿溫度不高,潛水蒸氣噴發可能會導致泥火山。
潛水蒸氣噴發通常包括蒸汽和岩石碎片,且液態熔岩很少。岩石碎片的溫度可以是冰冷,也可以是熾熱。如果有熔融岩漿一起噴發,火山學家會將該事件歸類為准岩漿型火山噴發。這種噴發偶爾會形成稱為低平火山口的寬闊低地形火山口。潛水蒸氣噴發常排放二氧化碳或硫化氫氣體。這對人體是有害的,因為足夠濃度的二氧化碳能造成窒息,而硫化氫是一種毒物。例子如1979年爪哇島的一次潛水蒸氣噴發,其造成140人死亡,其中大多數人是由於氣體中毒[3]。
參考文獻
- ^ 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.
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