Volcanoes

            Since Earth's early days, volcanic eruptions have shaped our planet and now we know they have shaped other planets as well. Volcanic eruptions constitute one of the minor natural disasters on the planet Earth because they cause fewer fatalities than earthquakes and famines (Encyclopedia Britannica). Even though, scientists have estimated that at least 200,000 persons have lost their lives as a result of volcanic eruptions during the last 500 years (Yorkshire Post).
             A volcano is a vent in the Earth from which molten rock and gas, erupt from the inside forming a hill or mountain around the vent. There are three different types of volcanoes, active, dormant, or extinct. An active volcano is one that erupts either continually or periodically. There are several active volcanoes in the continental United States: Lassen Peak in Lassen Volcanic National Park (California), Mt. St. Helens in Cascade Range (Washington State), and Mt. Katmai (Alaska) (Yorkshire Post). A volcano that has been known to erupt within modern times but is now inactive is classified as a dormant, or sleeping, volcano. Mt. Rainier (Washington), Mt. Hood (Oregon), and Mt. Shasta (California) are examples of volcanoes in the continental United States (Hale). A volcano not known to have erupted within modern history is classified as an extinct volcano. Although, Volcanologists consider truly extinct volcanoes to be those that have been worn away almost to the level of their magma chamber (Hale). .
             An exact number of existent volcanoes is unpredictable, nobody has really counted all of the volcanoes, especially the tens on thousands on the sea floor. In deed, the best guess is 1511 volcanoes have erupted in the last 10,000 years and should be considered active (Simkin & Siebert). .
             These eruptions had contributed in many good ways to our planet Earth. The earth's water and atmosphere are evolved from the gases produced by volcanic eruptions, helping to proof human beings life.