point. The resultant volcano is gently sloping with a wide diameter and forms a flattened shield or dome (Fig. Some of them have been harnessed to heat houses, swimming pools and for other domestic purposes. They occur along coastal mountain ranges, as off-shore islands and in the midst of oceans, but there are few in the interiors of continents. Popacata- petl and. Even the sea was boiling and all the ships in the harbour were wrecked. These metamorphosed rocks together with the solidified magma give rise to extensive batholiths, sometimes hundreds of miles in extent. Some spines are very resistant and while most of the material of very old volcanoes is removed by erosion the spine may remain,.g. The jet of water is usually emitted with an explosion, and is often triggered off by gases seeping out of the heated rocks (Fig. With the increasing studies done by scientists on volcanoes it is becoming possible to gauge the activity level of a volcano. Due to their high fluidity, they flow readily with a speed of 10 to 30 miles per hour.
Magma is formed when there is a decrease in pressure in the upper mantle. This area is usually at the subduction zones wherein tectonic plates move onto one another. The pressure lowering and movement of tectonic.
Essay on, volcanoes, essay
The spine was formed by the pasty lava, partially solidified in the neck of the volcano. Earthquakes and tsunamis add even more to the danger caused by an eruption. Part of the spine, however, crumbled under continual weathering as well as internal forces. The Lesser Antilles are made up mainly of volcanic islands and some of them still bear signs of volcanic liveliness. The most dangerous volcanic eruption recorded is the eruption of Mount. Advertisements: The tallest volcano in the world is the Ojos del Salado, a volcano in Chile. Volcanoes are generally concentrated on the edge of continents, along the island chain, or beneath the sea forming long mountain ranges. It arches up the overlying strata of sedimentary rocks,.g. Within this essay I will consider all contributory factors that may influence the processes which take place. As the magma approaches the surface of the earth, the solubility of water in the magma tends to decrease. Krakatau in August 1883. A laccolith is a large blister or igneous mound with a dome-shaped upper surface and a level base fed by a pipe-like conduit from below.
Essay on volcanic eruption
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