Earth 4_L5_ Marine Provinces

Bathymetry

Measurement of the depth and morphology of the ocean floor.

Abyssal plain

Large, flat, and deep regions between the continental margin and mid-ocean ridges.

Echo sounder

An instrument that emits sound signals downward to measure ocean depth by calculating the time it takes for the signals to return.

Marine provinces

Three main zones of the ocean: 1) Shallow continental margins, 2) Deep ocean basins, 3) Mid-ocean ridges.

Turbidity current

Density-driven sediment ‘avalanche’ that occurs underwater, often causing erosion and enlarging submarine canyons.

Submarine canyon

A steep-sided valley formed by the erosion of sediment and rock on the continental shelf.

Seafloor morphology

The study of the shape and features of the ocean floor.

Passive margin

A continent-ocean boundary that is not tectonically active with minimal geological activity.

Active margin

A tectonic plate boundary characterized by higher geological activity, including earthquakes and volcanoes.

Hydrothermal vent

Submarine hot springs that occur within the rift valley of a mid-ocean ridge.

Multibeam sonar

Sonar technology that emits multiple beams of sound waves to create detailed images of seafloor bathymetry.

Seismic reflection profile

A method using sound waves to create images of subsurface geological structures.

Lithogenous sediment

Sediment derived from pre-existing rock material that originated on continents or islands.

Biogenous sediment

Sediment derived from the hard parts of once-living organisms, such as shells and skeletal remains.

Hydrogenous sediment

Sediment derived from dissolved or precipitated materials in seawater.

Cosmogenous sediment

Sediment that originates from extraterrestrial sources, like meteorites.

Neritic deposits

Shallow, near-coastal sediment deposits typically found on continental shelves.

Pelagic deposits

Deep ocean basin deposits typically found on continental rises and abyssal plains.

Mid-ocean ridges

Continuous mountain ranges that run around the Earth, covering 23% of its surface.

Pillow lava

Smooth, rounded lobes of volcanic rock formed when hot molten lava cools quickly in contact with water.

Seamount

An underwater mountain formed by volcanic activity.

Continental slope

The steep drop-off between the continental shelf and the deep ocean floor.

Continental rise

A transition zone between the continental slope and the deep ocean floor characterized by thick sediment deposits.

Deep ocean trenches

The deepest parts of the ocean, often located near tectonic plate boundaries where subduction occurs.

Turbidite deposits

Sediment deposits formed from turbidity currents along continental slopes and rises.

Negative gravity anomaly

An area where gravitational pull is weaker than expected, often associated with deep ocean trenches.

Positive gravity anomaly

An area where gravitational pull is stronger than expected, often associated with mountain ranges or seamounts.

Graded bedding

A sedimentary layering that indicates variations in energy conditions during sediment deposition.

Seismic profiling

A technique using low-frequency sound waves to investigate sediment and rock layers beneath the seafloor.

Drilling core

A cylindrical sample of sediment that is extracted from the seafloor for geological study.

Ocean trench

A deep, narrow valley in the ocean floor created by the subduction of tectonic plates.

Seafloor spreading

The process by which new oceanic crust is created at mid-ocean ridges as plates pull apart.

Hydrographic surveying

The process of mapping the seafloor using techniques such as sonar to understand underwater features.

Bathymetric map

A representation of the underwater terrain created from bathymetric data showing depths and features of the seafloor.

Oceanic crust

The outer layer of the Earth's surface beneath the ocean, consisting mainly of basalt.

Continental crust

The thicker section of the Earth's crust that forms the continents, composed mainly of granite.

Mid-ocean ridge system

A global system of underwater mountains formed by plate tectonics and seafloor spreading.

Oozes

A type of sediment that accumulates on the sea floor, rich in biological materials, often forming from the remains of microorganisms.

Salinity

The concentration of salts in water, which affects its density and circulation patterns in the ocean.

Ocean circulation

The large-scale movement of water within the world's oceans, driven by factors such as wind, salinity, and temperature differences.

Thermohaline circulation

Deep ocean currents driven by temperature (thermo) and salinity (haline) differences, crucial for global climate regulation.

Ecosystem services

The benefits that humans obtain from ecosystems, including those found in the ocean such as fisheries and tourism.