Oceanography - The Deep Sea

the Trieste

A bathyscaphe which descended to the bottom of the Marianas Trench at 35,840 ft. deep (psi = 15,979) (atm = 1086)

thermocline

A narrow stratum of rapid temperature change in the top 1000 m of the ocean

chemosynthesis

Process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates

William Beebe and Otis Barton

used bathysphere to observe marine life off bermuda, they were the first ocean explorers to go deeper than light penetrated

James Cameron

1st human to reach the 11,000 m Marianas Trench solo in a submersible

mid-ocean ridge

An underwater moutain chain where new ocean floor is formed

hydrothermal vent

Form along mid-ocean ridges, and are zones where mineral, rich hot water escapes through cracks in ocean crust and into the surrounding water

abyssal zone

Lies below 2000 meters and is in complete darkness and uniform cold, the bottom for much of the ocean

hydrogenous sediments

Sea-floor sediments, such as manganese nodules, that form when chemical reactions cause minerals to crystallize from seawater

Mariana Trench

The deepest part of the world's oceans located in the western Pacific. It has a depth of 11,034 meters.

epipelagic

The pelagic environment from the surface to 200 m. Plenty of sunlight to promote photosynthesis.

mesopelagic

The twilight zone of the ocean, minimal light, oxygen minimum zone, and rapidly changing conditions.

continental shelf

a gently sloping , shallow area that extends outward from the edge of each continent

blob fish

a great example of a squishy, mushy, or gelatinous deep sea species

abyssal plain

a smooth, nearly flat region of the deep ocean floor

continental slope

a steep incline of the ocean floor leading down from the edge of the continental shelf to the abyssal plain

seamount

an underwater mountain rising above the ocean floor

bathypelagic

below 1000 meters, uniformly cold and dark, lacks any hard surfaces

lithogenous sediments

from land, transported to ocean by water, wind, ice, gravity

oxygen minimum zone

region in ocean below photic zone with depletion of oxygen where most decay/respiration happens

manganese nodules

round mineral formations that contain high concentrations of manganese, iron, copper, nickel, and cobalt

biogenous sediments

sediments formed from the remains of living organisms; shells, skeletal parts, coral, fecal pellets

hadopelagic zone

the deepest parts of the ocean, found only in deep sea trenches

calcite compensation depth

the depth in the oceans below which the rate of supply of calcite (calcium carbonate) disappears, organisms lack hard shells and are often gelatinous instead

bioluminescence

the production of light by living things, in the deep sea it is often use defensively or for camoflage