Submarine Canyons

Submarine Canyons

 

steep-sloped, often U-shaped and branching valley-like landforms that cut deeply (up to 1-2 km) into the submarine edges of continents. The submarine canyons usually begin on the shelf at a depth of several scores or hundreds of meters and terminate at the base of the continental slope or within the continental rise at a depth of 2-4 km. Outcroppings of bedrock are encountered in the sides of the submarine canyons; in the lower portion of the canyons lie debris fans that at times reach enormous sizes (with radii on the order of 300-350 km). Some submarine canyons are related to river valleys; in these instances they are the submarine continuations of these valleys (including those of the Congo, Indus, Ganges, and Amazon). In many instances, lee currents have probably been involved in the formation of the submarine canyons, but their origin is basically tectonic. Submarine canyons are widely found on ocean floors throughout the world. Along the shores of the USSR, large submarine canyons are encountered in the Black Sea, the seas bordering the Far East, and the Arctic Ocean.

References in periodicals archive ?
The new MPAs represent seamounts, submarine canyons, volcanic pinnacles, and a variety of ecosystem types on the shelf, continental margin, and abyss in both the Indian and Atlantic oceans.
Internal waves are amplified near sharp topographic breaks, such as submarine canyons crests, where many persistent egg deposition sites are located immediately up-shelf, thus, enhancing physicochemical variability.
In his presentation before defense and security experts, Carpio said based on French studies, China's strong interest and occupation of Panatag Shoal is due to the deep submarine canyons in the area that are ideal for secret submarine passages.
For example, transport (Vikebo et al., 2005; Christensen et al., 2007), stability of the water column (Coyle et al., 2008), mesoscale eddies (Allen et al., 2001; Logerwell & Smith, 2001; Leon-Chavez at al., 2010), coastal upwelling (Mann & Lazier, 1991), internal waves (Pineda, 1999), tidal currents (Le Fevre, 1986) and the interaction between waves and bathymetric features (e.g., submarine canyons) (Kunze et al., 2002).
Technicians aboard the ship are exploring the deep underwater habitats of the Gulf of Mexico using Remotely-Operated Vehicles (ROVs) and camera, the videos of which are sent back to the Okeanos Explorer, NOAA, allowing scientists on shore to explore methane seeps, mud volcanoes, submarine canyons, shipwrecks, brine pools including deep-sea coral habitats.
On the seaward side, the shelf ends abruptly in steep and gullied slopes that lead down to deeply incised submarine canyons. In its southern part the shelf passes more gradually into a gentle slope.
All other species were seen > 0.5 km of shore, often feeding near escarpments and submarine canyons. Endangered species, such as blue whales (Balaenoptera musculus) and humpback whales (Megaptera novaeangliae), were also recorded in the study area.
They are examining coral reefs and submarine canyons to detect earthquake fault zones.
The sediments washed down by the river form unstable submarine canyons
Sources of nutrients range from terrestrial outflow, to coastal upwelling, to cold seeps and hydrothermal vents; transport of resultant primary productivity includes free fall, surface, mid-water and bottom currents (including currents in submarine canyons and ridge valleys), and tidal pumping.
During the operations of Shalimar, the discovery of a complex intricate network of submarine canyons off the coast of Central Lebanon and the active deformation of the seabed that this complexity suggests, are revealing signs of the seismic risks associated with this peculiar geological situation of Lebanon.
To the north, a loamy beach faces the emerald-blue coastal waters of the Cuban seashelf, with coral reefs, underwater marine terraces and the submarine canyons of the Mani-Mani and the Morrillo rivers.

Full browser ?