Why does Europe have such a long and irregular coastline?

Europe’s long and irregular coastline is primarily the result of complex geological processes, most notably the impact of Pleistocene glaciation. During this epoch, massive glaciers acted as powerful agents of erosion, carving out deep valleys and transforming the physical landscape of northern and Alpine Europe.1

As these glaciers retreated and melted, global sea levels rose by approximately 320 feet (98 meters) or more, causing the ocean to flood coastal areas and create the continent's distinctive, jagged shape. This process resulted in a variety of coastal features, including submerged or "drowned" coastlines—such as those found in southwestern Ireland and northwestern Spain—as well as emergent coastlines characterized by raised former beaches. Additionally, the formation of fjords in regions like Norway further contributes to the rugged and irregular nature of the European periphery. These geological changes, which continued to shape the northern seas into their present form well into the Holocene Epoch, have provided the continent with extensive maritime access.123