The three Storegga Slides count among the largest recorded landslides. They occurred under water on the edge of Norway’s continental shelf (Storegga is Norwegian for "the Great Edge") in the Norwegian Sea, where an area the size of Iceland slid, causing a megatsunami in the North Atlantic Ocean.
The first slide occurred approximately 30,000-35,000 years before present. The second and third slides occurred very close together at approximately 7,000 years before present
Radiocarbon dating of sediments taken from the coastline of eastern Scotland show that a giant wave flooded the area in about 5,800 BC. At the time, Britain was joined to mainland Europe by a land bridge. Scientists believe the landslide triggered a 10-meter high tsunamis.
The slide was caused by material built up during the previous ice age, and that a reoccurrence would only be possible after a new ice age.