of these articles is concerned with the geological structure volcano, further meanings under volcano (term clarifying)
outbreak of the volcano Rinjani in the year 1994 with eruption thunderstorm

a volcano is a geological structure, which develops, if magma (melted rock) to to thoseSurface of a planet (z. B. the earth) ascends. One calls all accompaniments, which are connected with the withdrawal of the glow-liquid rock melt, volcanism.

The term “volcano” is derived from the Italian island Vulcano . In the Roman mythology appliedthis island as the Schmiede of the Vulcanus, the Roman God of the fire.

In a depth starting from 100 km, in which temperatures between 1000 and 1300 degrees Celsius prevail, rocks melt themselves to tough-plastic magma, in large, drop-shaped herds of magmain 2 to 50 km depth collects. If the pressure becomes too large, the magma ascends over columns and gaps of the lithosphere . Magma, which arrives in this way at the earth's surface, is called lava.

With a volcanic eruption becomenot only glow-liquid, but also firm or gaseous materials set free (volcanism).


of volcanos

of 6 Web on the left of volcanic types after its outside form and after thatKind of their magma supply system partition.

approx. 95% of the volcanos on earth are layer volcanos. On the other hand are approx. 90% of all active volcanos of sign volcanos.

a special form is the supervolcano (South German - supervolcanos)

volcanos can one also after its activity arrange in

  • active volcanos (active volcanism)
  • inactive volcanos (no active volcanism, are however given conditions for renewed activity)
  • extinct volcanos(by missing magma supply no more activity possible)

magma types

another possibility of classifying volcanos is, to describe them according to the type of the magma that both the developing form of the volcano and the outbreak behavior crucially certainly:

In summary one can say that “grey volcanos” form “layer volcanos”, while “red volcanos” bring “sign volcanos out”.

Many volcanos follow however not a “pure” outbreak sample, but show varying behavior either during an eruption or during the millions years of their activity. An example of itis the Ätna on Sicilies.

Distribution of volcanos

world-wide gives it about 1900 volcanos, which are regarded as active. One can understand their distribution with the help of the realizations of plate tectonics:

  • Volcanos of the spreading zones lie with few exceptions on thatSea-bottom, where the ground plates drift apart.
    The magma occurring there is basaltisch. To it mainly red volcanos or sign volcanos belong.
  • Volcanos of the Subduktionszonen are the most visible volcanos. They arise, where ground plates one on the other meet and the one ground plate under the other oneone pushes. That abbott-also-ends (often SiO 2 - is enough) rock in the depth is melted and rises, since it has a smaller density, upward, where it comes to eruptions. For this one counts mainly grey volcanos or layer volcanos.
Hot Spot
  • Volcanos over Hot Spots (also plume or Plutone called) are rare, since it determined world-wide to time only about 40 clearly “Hot Spots “gives (see also: List of identified Hot Spots). A “Hot Spot” is over long time (usually over100 millions Years) stationary melting range in the Earth's mantle under the lithosphere. Since the plates of the lithosphere push themselves during these long periods in the process of plate tectonics over a “Hot Spot” away, bead cord-like one behind the other new volcanos form, thus as became themthrough-weld by the crust. Most well-known example are the Hawaii - islands: the Hauptinsel Hawai'i, which lies as the youngest volcanic island over the “Hot Spot”, is only 400,000 years old, while the oldest of the 6 volcanic islands Kauai in the northwest already forwardsabout 5.1 million years originated in. A further example of this rare kind of volcanism is in the German volcanic Eifel.

Forecast of volcanic eruptions

emergence of volcanos at shelf borders

whether a volcano finally expired or perhaps again activelywill can, particularly interest humans, who live in the environment of a volcano. In each case a volcanic eruption has extensive consequences, because beyond the personal fate infrastructure and economics of the region concerned are lastingly affected. Therefore it is thatpriority aim of research to be able to predict volcanic eruptions as precisely as possible. Fehlprognosen would be alone devastating under cost criteria (evacuation thousands of humans, quiet putting of the entire economic life u.v.m.).

Despite certain thing in common no volcano in its outbreak behavior resembles the other one. Therefore are observations over dwell phasesor seismic activities of a volcano hardly transferably to another.

In addition, strengthens arising easy earthquakes or an intensified gas output interprets one as vague signs of a forthcoming eruption, this can only 50 years later take place.

Deformations are more expressivethe earth's crust directly over the magma stove. With laser measurement the smallest distance changes are seized. So both directly before the outbreak of the Mount Saint Helens has itself 1980 and before the outbreak of the Pinatubo 1991 the earth over the magma stovebulged. Thus the Vulkanologen could forecast the outbreaks few days before.

Nevertheless one must state that despite intensive research and employment of most modern technical aids the reliable accurate forecast of a volcanic eruption is at present not yet in each case possible.

Well-known volcanos

eruption at the Stromboli

the most well-known (active) volcanos in Europe are:

some well-known volcanos outside of Europe are:

Vulkan Arenal, Costa Rica
Volcano Arenal, Costa Rica
Der Hohentwiel bei Singen
The Hohentwiel when singing

volcanos expired in Germany:

Whether the German volcanos asexpired and/or. resting apply, is at present still disputed. It seems a little probably that they become again active within the next centuries, but mehren themselves the signs for size increase of the magma plume for example under the Eifel. Carbon dioxide vesicle, e.g.into the Maaren ascend, in recent time no longer than symptom lining Inge that activity are interpreted, but than indications of increasing activity. Penetrating water (groundwater, Oberflächenwasser) lends to the Eifel volcanos besides special danger, there by the enormous pressure build-up a highly explosiveMixture develops and it to Phreatomagmati explosions to come can. Already with the last outbreak before 11,000 years thereby tremendous quantities of magma, ash and cinder to the earth's surface were carried.

The northernmost volcano of the world is the 2277 m high volcanoHaakon VII Toppen/berry mountain on the island January Mayen, it became 1970 after long peace again actively.

The southernmost volcano of the world is the 3794 m high Mount Erebus on the Ross island in the Antarctic, it is constantactively.

The highest volcano of the world is to newest government inspection department - measurements of the 6882 m high Monte Pissis in Argentina.

The highest volcano of the solar system (however already expired) is the Olympus Mons on Mars. It is with 26,4km height the highest well-known mountain of our solar system, which for a former sign volcano is extraordinarily remarkable.

On the Venus are there likewise numerous extinct volcanos, during active volcanos except on the earth so far only on the Jupitermond IOadmits are (see in addition also Cryovulkan).

Further volcanos on earth and in our solar system are to be found under list of the volcanos.

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Wiktionary: Volcano - word origin, synonyms and translations
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