Affects of Volcanoes

מקצוע
מילות מפתח ,
שנת הגשה 2005
מספר מילים 824
מספר מקורות 10

תקציר העבודה

The plates which are about 20 miles thick, make up the earth's crust and are a chief cause of volcanic activity. These plates are always in motion. They move very slowly, however some at times bump in to each other. These movements put a lot of pressure on the surface rock. Volcanoes obtain their energies from such movement and pressure. Volcanoes form at the boundaries of these plate where two types of movement occurs, two plates will collide with each other or the plates will move apart from each other. Some of these plates layers are cooled and are made up of rigid rocks.