Landslides are merely massive movements of earth sliding down a cliff, mountain, or slope. Mudslides, also called debris flows or mudflows, are a type of landslide that involves fast-moving debris, or saturated earth (mud) flowing in a channel. Rockslides are avalanches of rocks falling down a mountain, slope, or cliff. Certain areas are more prone to landslides, but landslides are usually triggered by a specific event, often something weather-related. Recent weather conditions in California may have increased the likelihood of landslides and rockfalls. Some common natural incidents that cause landslides include heavy rains, rapid snowmelt, wet conditions, earthquakes, and erosion. All of these conditions alter the soil conditions and increase the likelihood that a landslide will occur.