A volcano is a vent or a group of closely spaced vents through which molted rocks magma and hot gases come out of deep seated sources. It has three important parts.
(i) Vents. The hot rock material and gases come out of a zigzag hole. This hole is known as vent.
(ii) Cone. The ejected rock material rushing out of the vent creates a cone like formation at the upper end of the vent. The cone has a steep slope and sometimes takes the form of a mountain.
(iii) Crater. A mouth opens at the upper peak of the cone. Molten material is ejected from this mouth. This mouth is funnel shaped. Its walls are almost vertical and are known as crater. Large sized craters are called camera. The diameter of a crater measure a few km.
Calderas, as mentioned, are circular in form and have circular but vertical walls. When the volcanoes are dormant, water accumulates in them and a lake is formed. These lakes are known as crater lakes. A crater called La Caldera situated in Canary Island has a diameter of 4.8 ton. It is surrounded by mountain walls about 4825 meters high. Among the Calderas of Hawaii, Kilauea and Mauna Loa are worth mentioning.
Material Ejected from a Volcano
In average a volcano in an explosion ejects 150 cubic km of material. In millions of years the ejected material becomes tremendous. The largest volcanic island among the Hawaiian group of islands has a volume of one hundred thousand cubic km when measured above the sea level.
Locals hypothesize that the legacy of Italian blood and culture in Cologne, colonized by the Romans more than 1500 years ago, makes the people more jovial and lighthearted. Cologne is the largest city on the Rhine.
Kolsch is not only the dialect spoken here but, also the name of their own top-fermented beer. There are more than 4,000 pubs, restaurant's and brewery taverns in Cologne.
Unlike many of the world's large cities, Cologne, with a population of over a million, gets better every day, there are more things to do and see, more new and innovative buildings... more
Travel is an opportunity to learn, whether geography, languages, history or other subjects.
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Cologne is situated on the beautiful Rhine River.