Surface changes occur in two ways. Slow change on the surface: The change that occurs on the surface for a long time due to external forces is the slow change . Erosion of the earth's surface by its rapid flow , which causes changes in the earth's surface. In addition , human beings are undergoing various changes in the earth's surface, such as building roads , houses , cities, people are always fragmenting the earth's surface. Sudden change in the surface of the earth: Rapid change in the surface of the earth is called sudden change. Earthquakes , volcanic eruptions , tsunamis, etc. are examples of sudden changes in the surface of the earth.