VOLCANIC ERUPTIONS — FORMS AND PRODUCTS ERUPCJE ...kosmos.icm.edu.pl/PDF/2011/219-ang.pdf ·...
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VOLCANIC ERUPTIONS — FORMS AND PRODUCTS Summary A volcano is an opening in the Earth’s surface where eruptions can take place and lava flows, py- roclastic material and volcanic gases escape from a magma reservoir. Volcanoes can be classified as ef- fusive, explosive or composite (stratovolcanoes). The explosivity of eruption depends on the chemi- cal composition, viscosity and volatile content of the magma. Most magmas are silicate melts; after degassing during eruption, they are termed lavas. The explosivity of an eruption depends mainly on the content of juvenile water in the magma (mag- matic eruption), and on the extent of interaction of extruded magma with surface water (phreatic erup- tion). The products of effusive eruption are lava flows and lava domes; for explosive eruption they are mainly bombs, lapilli and ashes.
Transcript of VOLCANIC ERUPTIONS — FORMS AND PRODUCTS ERUPCJE ...kosmos.icm.edu.pl/PDF/2011/219-ang.pdf ·...
225Erupcje wulkaniczne — formy i produkty
spotykanym typem magmy są magmy krzemianowe, które po wydostaniu się na powierzchnię nazywamy lawami. Eksplozywność erupcji zależy w dużej mierze od zawartości wody w magmie (erupcje magmowe), jak również od reakcji gorącej, intrudującej magmy z wodami powierzchniowymi (freatyczne erupcje). Naj-częstszymi produktami efuzywnych erupcji są potoki i kopuły lawowe, natomiast eksplozywnych — bomby, lapilli, popioły i pył.
Termin „wulkan” dotyczy tych nieciągłości w sko-rupie ziemskiej, w których doszło do erupcji, czyli wy-rzucenia przez wulkan lawy, materiału piroklastyczne-go lub substancji lotnych (gazów wulkanicznych). Ze względu na charakter erupcji wyróżnia się wulkany efuzywne, eksplozywne i mieszane (stratowulkany). Charakter i rozmiar erupcji zależą od wielu czynni-ków w tym min. od składu chemicznego magm, lep-kości magm, zawartości gazów. Na Ziemi najczęściej
ERUPCJE WULKANICZNE — FORMY I PRODUKTY
Streszczenie
VOLCANIC ERUPTIONS — FORMS AND PRODUCTS
Summary
A volcano is an opening in the Earth’s surface where eruptions can take place and lava flows, py-roclastic material and volcanic gases escape from a magma reservoir. Volcanoes can be classified as ef-fusive, explosive or composite (stratovolcanoes). The explosivity of eruption depends on the chemi-cal composition, viscosity and volatile content of the magma. Most magmas are silicate melts; after
degassing during eruption, they are termed lavas. The explosivity of an eruption depends mainly on the content of juvenile water in the magma (mag-matic eruption), and on the extent of interaction of extruded magma with surface water (phreatic erup-tion). The products of effusive eruption are lava flows and lava domes; for explosive eruption they are mainly bombs, lapilli and ashes.
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