A steep coastBird, Eric (2008). ''Coastal Geomorphology: An Introduction'', 2nd ed., Wiley, Chichester, 2008. is a stretch of

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

line where the

mainland Mainland is defined as "relating to or forming the main part of a country or continent, not including the islands around it egardless of status under territorial jurisdiction by an entity" The term is often politically, economically and/or demogr ...

descends abruptly into the sea. There is a sharp transition from the land to sea as opposed to that on a flat coast where the land descends gradually seawards. The height of the land on a steep coast is well above

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

. Most steep coast are rocky

cliffed coast A cliffed coast, also called an abrasion coast, is a form of coast where the action of marine waves has formed steep cliffs that may or may not be precipitous. It contrasts with a Flat coast, flat or alluvial coast. Formation In coastal ar ...

s (also called abrasion coasts), where the

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

processes of wave action result in a steep declivity. Another type of steep coast is the

fjord In physical geography, a fjord (also spelled fiord in New Zealand English; ) is a long, narrow sea inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Antarctica, the Arctic, and surrounding landmasses of the n ...

which is formed when a

glacial valley U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight s ...

lies partially under water as a result of a rise in sea levels. In

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

there are fjords whose almost vertical sides tower over 1,000 metres above the water and plunge 300 metres below it. On

volcanic island Geologically, a volcanic island is an island of volcanic origin. The term high island can be used to distinguish such islands from low islands, which are formed from sedimentation or the uplifting of coral reefs (which have often formed ...

s the sea can enter the

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

and the face of the

volcanic pipe Volcanic pipes or volcanic conduits are subterranean geology, geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. They are considered to be a type of ''diatreme''. Volcanic pipes are composed of a deep, narro ...

can form a steep coastline. The best-known example of that is

Santorini Santorini (, ), officially Thira (, ) or Thera, is a Greek island in the southern Aegean Sea, about southeast from the mainland. It is the largest island of a small, circular archipelago formed by the Santorini caldera. It is the southern ...

in the archipelago of the

Cyclades The CYCLADES computer network () was a French research network created in the early 1970s. It was one of the pioneering networks experimenting with the concept of packet switching and, unlike the ARPANET, was explicitly designed to facilitate i ...

in Greeces.

Fira Firá (, pronounced , official name Φηρά Θήρας - ''Firá Thíras'') is the modern capital of the Greece, Greek Aegean Sea, Aegean island of Santorini (Thera). A traditional settlement,http://www.visitgreece.gr Greek National Tourism Or ...

, the main town of the island, lies on the rim of the caldera which is around 300 metres above the sea and drops below it for another 200 metres.

References

{{Authority control Geomorphology Coastal geography Coastal and oceanic landforms