Ocean_depths | TriviaQuestions.online

⭐ Core Definition: Ocean depths

The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of 200 m (660 ft) or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combination of low temperatures, darkness, and high pressure. The deep sea is considered the least explored Earth biome as the extreme conditions make the environment difficult to access and explore.

Organisms living within the deep sea have a variety of adaptations to survive in these conditions. Organisms can survive in the deep sea through a number of feeding methods including scavenging, predation and filtration, with a number of organisms surviving by feeding on marine snow. Marine snow is organic material that has fallen from upper waters into the deep sea.

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👉 Ocean depths in the context of Ocean temperature

The ocean temperature plays a crucial role in the global climate system, ocean currents and for marine habitats. It varies depending on depth, geographical location and season. Not only does the temperature differ in seawater, so does the salinity. Warm surface water is generally saltier than the cooler deep or polar waters. In polar regions, the upper layers of ocean water are cold and fresh. Deep ocean water is cold, salty water found deep below the surface of Earth's oceans. This water has a uniform temperature of around 0-3 °C. The ocean temperature also depends on the amount of solar radiation falling on its surface. In the tropics, with the Sun nearly overhead, the temperature of the surface layers can rise to over 30 °C (86 °F). Near the poles the temperature in equilibrium with the sea ice is about −2 °C (28 °F).

There is a continuous large-scale circulation of water in the oceans. One part of it is the thermohaline circulation (THC). It is driven by global density gradients created by surface heat and freshwater fluxes. Warm surface currents cool as they move away from the tropics. This happens as the water becomes denser and sinks. Changes in temperature and density move the cold water back towards the equator as a deep sea current. Then it eventually wells up again towards the surface.

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In this Dossier

⭐ Core Definition: Ocean depths
👉 Ocean depths in the context of Ocean temperature
Ocean depths in the context of Pelagic sediments
Ocean depths in the context of Polychaete

Ocean depths in the context of Pelagic sediments

Pelagic sediment or pelagite is a fine-grained sediment that accumulates as the result of the settling of particles to the floor of the open ocean, far from land. These particles consist primarily of either the microscopic, calcareous or siliceous shells of phytoplankton or zooplankton; clay-size siliciclastic sediment; or some mixture of these, along with detritus (marine snow) included. Trace amounts of meteoric dust and variable amounts of volcanic ash also occur within pelagic sediments. Based upon the composition of the ooze, there are three main types of pelagic sediments: siliceous oozes, calcareous oozes, and red clays.

The composition of pelagic sediments is controlled by three main factors. The first factor is the distance from major landmasses, which affects their dilution by terrigenous, or land-derived, sediment. The second factor is water depth, which affects the preservation of both siliceous and calcareous biogenic particles as they settle to the ocean bottom. The final factor is ocean fertility, which controls the amount of biogenic particles produced in surface waters.

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Ocean depths in the context of Polychaete

Polychaeta (/ˌpɒlɪˈkiːtə/) is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (/ˈpɒlɪˌkiːts/). Each body segment has a pair of fleshy protrusions called parapodia which bear many chitinous bristles called chaetae, hence their name.

More than 10,000 species have been described in this diverse and widespread class; in addition to inhabiting all of the world's oceans, polychaetes occur at all ocean depths, from planktonic species living near the surface, to a small undescribed species observed through ROV at the deepest region in the Earth's oceans, Challenger Deep. In addition, many species live on the abyssal plains, coral reefs, parasitically, and a few within fresh water.

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Ocean depths in the context of "Ocean temperature"

⭐ In the context of ocean temperature, what is a defining characteristic of deep ocean water compared to surface waters?

⭐ Core Definition: Ocean depths

👉 Ocean depths in the context of Ocean temperature

Ocean depths in the context of Pelagic sediments

Ocean depths in the context of Polychaete