Transform Boundaries
When two plates slide past one another, that area is called a transform boundary. The plates move in the same direction or opposite directions at different rates. An earthquake occurs when one plate slips past another plate. Most transform boundaries are found on the ocean floor. They commonly have zig-zag plate margins, where shallow earthquakes occur . A few, however, occur on land. The San Andreas Fault in California was formed when the Pacific plate was sliding past the North American plate.