Continental margin in the context of "Passive margin"

A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island is known as an "insular shelf."

The continental margin, between the continental shelf and the abyssal plain, comprises a steep continental slope, surrounded by the flatter continental rise, in which sediment from the continent above cascades down the slope and accumulates as a pile of sediment at the base of the slope. Extending as far as 500 km (310 mi) from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. The continental rise's gradient is intermediate between the gradients of the slope and the shelf.

An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000 metres (9,800 and 19,700 ft). Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. They are among the flattest, smoothest, and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins, the other elements being an elevated mid-ocean ridge and flanking abyssal hills.

The creation of the abyssal plain is the result of the spreading of the seafloor (plate tectonics) and the melting of the lower oceanic crust. Magma rises from above the asthenosphere (a layer of the upper mantle), and as this basaltic material reaches the surface at mid-ocean ridges, it forms new oceanic crust, which is constantly pulled sideways by spreading of the seafloor. Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. Much of this sediment is deposited by turbidity currents that have been channelled from the continental margins along submarine canyons into deeper water. The rest is composed chiefly of pelagic sediments. Metallic nodules are common in some areas of the plains, with varying concentrations of metals, including manganese, iron, nickel, cobalt, and copper. There are also amounts of carbon, nitrogen, phosphorus and silicon, due to material that comes down and decomposes.

The continental rise is a low-relief zone of accumulated sediments that lies between the continental slope and the abyssal plain. It is a major part of the continental margin, covering around 10% of the ocean floor.

An ocean bank, sometimes referred to as a fishing bank or simply bank, is a part of the seabed that is shallow compared to its surrounding area, such as a shoal or the top of an underwater hill. Somewhat like continental slopes, ocean bank slopes can upwell as tidal and other flows intercept them, sometimes resulting in nutrient-rich currents. Because of this, some large banks, such as Dogger Bank and the Grand Banks of Newfoundland, are among the richest fishing grounds in the world.

There are some banks that were reported in the 19th century by navigators, such as Wachusett Reef, whose existence is doubtful.

The extended continental shelf, scientific continental shelf, or outer continental shelf refers to a type of maritime area established as a geo-legal paradigm by the United Nations Convention on the Law of the Sea (UNCLOS). Through the process known as the extension of the outer limit of the continental shelf or establishment of the outer edge of the continental margin, every coastal state has the privilege, granted by the international community of nations, to acquire exclusive and perpetual rights to exploit the biotic and abiotic resources found on the seabed and subsoil of these maritime areas. These areas are located beyond the 200 nautical miles (370 km; 230 mi) that make up the state's exclusive economic zone (EEZ) and would otherwise be considered international waters.

In these deep-water areas, resource exploitation has been either technically impossible with available methods or otherwise economically unfeasible. Recently, however, sustained scientific and industrial progress and new technologies have enabled these oceanic waters to become increasingly accessible, which gives these areas extraordinary geopolitical and geoeconomic importance.

39°39′54″N 72°28′26″W / 39.665°N 72.474°W / 39.665; -72.474

The Hudson Canyon is a submarine canyon that begins from the shallow outlet of the estuary at the mouth of the Hudson River. It extends out over 400 miles (640 km) seaward across the continental shelf, finally connecting to the deep ocean basin at a depth of 1.9–2.5 mi (3–4 km) below sea level. It begins as a natural channel of several kilometres width, starting as a 66–131-foot (20–40 m) depression at Hudson Channel southward from Ambrose Light, then carving through a deep notch of about 0.62 mi (1 km) depth in the shelf break, and running down the continental rise. Tidally associated flows of about 30 cm/s (1.1 km/h) up and down the deeper parts of the canyon have been recorded. As silt, sand and mud are carried down the Hudson River, they flow into the canyon and out into the deep sea.