Internal and external parts of a volcano Essay Example For Students

Internal and external parts of a volcano Essay It then lows downhill from the eruption point until it cools and hardens. Main Vent ? A volcanos main vent is the point in the Earths crust where hot magma has reached the surface. The familiar cone-shaped volcano builds up as ash, rock and lava ejected during eruptions fall back to Earth around the vent. Crater A volcanic crater is a circular depression in the ground caused by volcanic activity. A volcanos vents are located at the bottom of the crater. Prophylactic Flow Prophylactic flows are fast moving currents Of hot gas and rock With travel down hill from a volcano, reaching speeds of 700 km/hour. The gas can reach temperatures of more than 1 ,OHO degrees C, and is one of the greatest dangers from volcanic eruptions. Ash Cloud Volcanic ash consists of small pieces of pulverize rock and glass created during volcanic eruptions. These fragments are so small, and heated to such a temperature that they can be carried in the air for many kilometers. Volcanic Bombs Volcanic bombs are chunks of lava blasted into the air which solidify before they reach the ground, Some bombs can be extremely large, measuring 5-6 meters in diameter and landing more than 500 meters from the volcanic vent, Secondary Vent ? On large volcanoes, magma will reach the surface through several different vents, and not just the main vent. This can form cones, eject lava, and cause destruction. Secondary Cone Secondary cones build up around secondary vents on larger volcanoes.