Final answer:
Active volcanoes are not found in southern California because they are not located along any plate boundaries or hot spots.
Step-by-step explanation:
Active volcanoes are not found in southern California because they are not located along any plate boundaries or hot spots. The presence of active volcanoes is typically associated with plate boundaries or areas where heat from the Earth's interior is rising. Southern California is not located near any plate boundaries, and the closest hot spot activity is found in the Hawaiian Islands, which are thousands of miles away.