the most well-known form of volcanism is the volcanic eruption. The magma chamber of the volcano empties itself in more or less violent way.
kinds of outbreaks
dangerous are particularly explosive outbreaks, throughOverheating by reason and/or sea waters over the magma chamber of the volcano to be released. They can blow up suddenly kubikkilometergrosse Gesteinsmassen into air. Also the volcanic eruptions under glaciers belong to this category. Often thereby a characteristically formed far Krater, the Caldera develops. Becomes the Calderaflooded, a Kratersee forms. The devastating outbreak of the Krakatau 1883, Indonesia was such an explosive outbreak. The remainders of the Caldera are today as four small islands in this and/or. over this Kraterlagune arranged and is in the Sundastrasse between the Indonesian islands Sumatra and Java. Such outbreaks cause also tsunami, Tsunamis, which affects thousands of kilometers.
Also pyroklastische outbreaks are dangerous, with which hot glow and ash clouds with large speed move avalanche-like slope downward and drag along everything and buried under itself. The notoriousOutbreaks of the Vesuv in the year 79 and the Mt. Pelée 1902 fall under this category. In each case thousands of humans were surprised and killed in shortest time by pyroklastischen rivers.
Lahare, those are just as dangerous in the worst case over many kilometers one up to 5m high Schlammstrom form, which can away-roll with a speed up to 100 km/h.
as so dangerously do not apply completely the effusiven outbreaks, with which the magma is not so strongly interspersed with gases and liquid. Particularly sign volcanos bendto such outbreaks, which dragged on in the past until over several hundred years (particularly in the warm periods of the ice age), whereby slowly a very flat rising volcanic cone constructed itself. A typical example would be for instance the Skjaldbreiður in Iceland.
Volcanic eruptions in history
- Montserrat, 1997, to 25. Glow avalanches several localities , 10 humans destroy June die and 20 are missed. In the following weeks the capital Plymouth and the airport are destroyed by glow and mudslides. Two thirds of the island become uninhabitable.
- Pinatubo, 1991, the Philippines, most violent outbreak in 20. Century, 1,000 dead ones; Scientists had interpreted and over 10000 humans could the signs of a forthcoming outbreak correctly in time be evacuated.
- Nevado del Ruiz 1985, Colombia, 13. November - a mudslide (Lahar)more than 25,000 inhabitants of 70 km kill remove lying city Armero. Similar outbreaks took place 1845 and 1595.
- Mount pc. Helens, the USA 1980, 18. May - as expired valid mountain fallow abruptly, in the middle in a protected area. By thoseenormous explosion is blown off the entire point of the mountain - in an environment of 400 square kilometers practically the entire Flora and fauna are destroyed. One estimates that the volcano with Kraft of approximately 350 megatons - the 27.000-fachen of the atom bomb dropped over Hiroshima -raged. 57 humans die with the outbreak.
- Nyiragongo, 1977, Zaire, 10. January - as harmless valid Nyiragongo 2,000 humans break out after several decades of the peace surprisingly and kill.
- Eldfell, 1973, 23. February - on the Icelandic island Heimaey develops surprisingly a new volcano. Humans can save themselves, but the city near the mountain is destroyed to considerable parts.
- Surtsey, 1963, 14. November - a volcano develops from the sea, after few days has it a length of 600 metersand a height of 60 meters reaches. Lava flowed from the Krater and developed a new island, which is 1.4 square kilometers large.
- Gunung Agung, 1963, Bali, 17. March - with this outbreak 1,900 humans, it die give 2,500 hurt to deplore.The volcanic activity at the surface expired soon thereafter, but some regions are still heated up after weeks so that one cannot enter them.
- Ätna, 1928, 2. November - the outbreak is the strongest of the volcano since 1669. But onethe danger recognizes in time, and which humans can do are evacuated.
- Kelud on Java, 1919, the water of the Kratersees forms Lahars, 65,000 dead ones.
- Mt. Pelée on the island Martinique, 1902, 8. May, 28,000 dead ones, the city Saint Pierre destroys
- Krakatau, 1883, 26. /27. August., two thirds of the volcanic island, officially 36,417 dead ones are blown up, mainly due to tsunamis high up to 40 m. It is one of the most catastrophic volcanic eruptions in the history, which became atmospheric shock waves of the explosion world-wide registered. The Aschevolken releases a volcanic winter,the temperature on the earth's surface sinks in the next two years noticeably.
- Tambora on Sumbawa (Indonesia), 1815, 10. April - 15. April 1815, 12,000 dead ones, further 50,000 to 80,000 die by the following earthquakes and tsunami as well as the ashtray gene on Lombok,largest volcanic eruption of the last 10,000 years. The outbreak had a VEI 7 Vulkanexplosivitätsindex; the VEI scale is enough from 0 to 8. By the entry of large ash quantities into the atmosphere the sun exposure is weakened in such a way that the year 1816 as a year without summers in North America andParts of Europe history enters.
- Lakagígar (Lakispalte) 25 km long volcanic column (altogether more than hundred Krater) on Iceland, June 1783 - March 1784: one of the largest eruptions in historical time. The Kratern entfloss a lava quantity of 12,3 billion m ³, itself upa surface of 565 km ² distributed. Ash (Fluor - precipitation) poisons the pastures on the whole island Iceland; the ascending clouds produce harvest failures in completely Europe. In the next 3 years more than 1/5 of the population of island at hunger and diseases die.
- Ätna, 1669,8. March - 16. May, which become city Malpasso and six localities destroyed, the city Catania damages
- Vesuv, 1631, 16. December, approx. 30.000 dead ones, about 80 localities damages
- Ätna, 1169, about 15,000 dead
- Eldgjá, 936 n. Chr., an enormous fire columnone of the largest lava fields of the world breaks open on Iceland and produces (approx. 9 km ²).
- Vesuv, 79 n. Chr., 24. August, Zerstörung of the cities Pompeji and. Herculaneum, over 2.000 dead ones (inclusive Plinius the older one).
- Santorin, 1628 v. Chr., Numberthe victims unknown, inhabitants of the city Akrotiri could leave possibly in time the island; indirectly (ashtray gene, possibly. Flutwelle) possibly strong effects on far parts of the Ägäisraums.
- Toba on Sumatra, approx. 74,000 v. Chr., 3,000 Kubikkilometer material are hurled into the air, which becomes earth temperaturein the volcanic winter around 5 degrees lowered, the Homo sapiens nearly becomes extinct.
- Yellowstone Supervulkan, forwards approx. 2 million, 1.3 million and 630,000 years took place here large outbreaks. Researchers fear a global climatic disaster with a renewed outbreak (in geologically close time one expects).
- Fish Canyon Tuff event in Colorado, forwards approx. 27,8 millions Years, possibly largest volcanic eruption of geologic history, volcano 5,000 Kubikkilometer lava eject.