A large and fierce storm, a hurricane starts in the tropical areas of the Pacific, North Atlantic, or Indian oceans, where it gathers great quantities of moisture and thermal energy, or heat. It is circular in shape, spiraling inward toward a nearly calm center that is called the eye of the hurricane. A hurricane may blow inland, where its high winds (ranging from 75 to 200 miles [121 to 322 kilometers] per hour) and hard rain can cause terrible damage and coastal flooding. A hurricane might spread over an area up to 600 miles (966 kilometers) wide and last for well over a week. Once a hurricane moves over cooler ocean waters or land, though, it begins to lose its strength. In some parts of the world hurricanes are called typhoons.