Volcano

Natural Disasters - Volcano Volcanic eruptions may come about it many different ways. Some are on a large-scale, and other are small eruptions. Small eruptions occur in places like Hawaii, whereas infrequent supervolcano's occur in places like Lake Toba. The word Volcano comes from the word "Vulcan" which is the god of fire in Roman mythology. Lava comes out of a volcano and contains a high percentage of silica, and tends to be highly viscous. Volcano's can be classified in five different shapes: Shield volcanos Cinder cones Composite volcanos Supervolcanos Submarine volcanos. Volcano's can either be active, dormant or extinct. Active volcano's are volcano's showing no sign of rest. Dormant volcano's are currently not active but could possibly erupt again. Extinct volcano's are those highly unlikely. Volcano's don't necessarily have to be on earth. The largest mountain in this galaxy in this solar system - Olympus Mons, is a volcano but is extinct. Lava from volcano's is acidic and therefore is a contribution towards acid rain. The high temperatures causes nitrogen dioxide to be converted into nitric oxides and therefore contributes towards acid rain, photochemical smog, ozone depletion, and global warming. Example: In the 1815, the Indonesian eruption threw rocks more than 100 cubic km of ash killing 92,000 people. The island was lowered by 1.25 km. The greatest volcanic explosion occurred in Indonesia in 1883, which resulting in rocks hurling 55km up into the air. The explosion was heard in Australia and generated a 40m high tsunami, killing 36,000 people. Smoking Bromo and Semeru volcanoes on Java in Indonesia. A volcanic eruption can be devastating for the local wildlife, as well as the human population. Mount St. Helens erupting in 1980