Oh my god, Karen, you can't just ask people why they're white.
Most of the world's volcanoes are found around the edges of tectonic plates, both on land and in the oceans. On land, volcanoes form when one tectonic plate moves under another. When enough magma builds up in the magma chamber, it forces its way up to the surface and erupts, often causing volcanic eruptions.
The answer is Gully Erosion. It is known as the least common yet would cause the most dramatic visible change in the landscape. The cuts that are deep in the soil would leave large gullies that would expand through erosion.
