Volcanoes

In addition, another advantage of volcanoes to the environment is to provide nutrients to the surrounding soil. Also, volcanic ash, which is a volcanic rock, exploded from a vent in fragments less than 2mm in size. Volcanic ash-particles are like small sharp glass-particles that damage anything they come across. Because volcanic ash may fall on many things it is very harmful to the environment around the volcano. In addition, ashes often contain minerals that are beneficial to plants, and if it is very fine ash it is able to break down quickly and get mixed into the soil. Finally, volcanic gases (The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen.) are the source of all the water (and most of the atmosphere) that we have today (Simkin & Siebert). Furthermore, volcanoes have done wonderful things for the Earth because they helped cool off the earth removing heat from its interior. Besides, volcanoes make islands and add to the continents, making our planet wider and comfortable for human beings. .
             Volcanic eruptions may not be so dangerous, but still we must be precocious. A volcanic eruption constituted a group of components and parts that work together in order to liberated the lava. Scientists use the term "magma- for molten rock underground and "lava- for molten rock that breaks through the Earth's surface. In other words, lava is magma above the ground (Encyclopedia Britannica).
             Volcanoes erupt because of density and pressure that is generated in its bottom. The lower density of the magma (very hot liquid rock found below the Earth's surface) relative to the surrounding rocks causes it to rise. More specific, it will rise to the surface or to a profundity that is determined by the density of the magma and the weight of the rocks above it. As the magma rises, bubbles start to form from the gas dissolved in the magma.