Doggerland was submerged by a tsunami formed in what ocean?
Storegga Slide The three Storegga Slides are considered to be amongst the largest known landslides. They occurred under water, at the edge of Norway's continental shelf in the Norwegian Sea, approximately 6225–6170 BCE. The collapse involved an estimated 290 km length of coastal shelf, with a total volume of 3500 km3 of debris, which caused a very large tsunami in the North Atlantic Ocean.
East Frisian Islands The East Frisian Islands (German: "Ostfriesische Inseln", West Frisian: "Eastfryske eilannen") are a chain of islands in the North Sea, off the coast of East Frisia in Lower Saxony, Germany. The islands extend for some 90 km from west to east between the mouths of the Ems and Jade / Weser rivers and lie about 3.5 to 10 km offshore. Between the islands and the mainland are extensive mudflats, known locally as "Watten", which form part of the Wadden Sea. In front of the islands are Germany's territorial waters, which occupy a much larger area than the islands themselves. The islands, the surrounding mudflats and the territorial waters (The "Küstenmeer vor den ostfriesischen Inseln" nature reserve) form a close ecological relationship. The island group makes up about 5% of the Lower Saxony Wadden Sea National Park.