Oceans Module Exam Review

Abyssal plain

A large, flat, and deep portion of the ocean surrounding either side of a mid ocean ridge.

Guyot

A large, flat-topped underwater volcano.

Thermocline

A layer of rapid temperature change. As the input of solar energy decreases with depth, the temperatures quickly drop to near freezing. The depth of this layer depends on the climate of an area.

Volcanic island arc

A line of volcanic islands caused by subduction and the melting of either oceanic or continental crust.

El Nina

A massive upwelling along the coast of South America which makes the surface waters over eastern tropical pacific unusually cold."

Continental Slope

A sharp drop in depth where the ocean basin truly begins and the continental crust ends.

Gyre

A surface current loop.

Gulf Stream

A warm ocean current that flows from the Gulf of Mexico northward through the Atlantic Ocean.

Surface Current

A wind-driven current. Can occur in coastal regions as well as in the open ocean. A wind's strength and the length of time that it blows determine the strength and direction. Because winds are deflected by the Coriolis effect, these follow the same pattern.

Ocean trench

An extremely deep portion of the ocean, similar to a canyon, formed during subduction. The deepest ocean trench is the Mariana Trench in the Pacific Ocean. It reaches a depth of about 11 kilometers.

Tectonic Plates

An irregular section of the lithosphere that floats on the earth's mantle.

El Nino

An irregularly occurring and complex series of climatic changes affecting the equatorial Pacific region and beyond every few years, characterized by the appearance of unusually warm, nutrient-poor water off northern Peru and Ecuador, typically in late December.

Mid-Ocean Ridge

An underwater mountain chain where new ocean floor is formed.

Seamount

An underwater mountain. If the mountain breaks the water surface, it is known as an island.

Surface water

As deep as 300 meters, ocean water maintains a relatively constant temperature because of mixing and the input of solar energy.

Land Breeze

At night, the ocean loses heat to the atmosphere, causing winds from the land to blow toward the ocean.

Global Conveyor Belt

Currents that connect and run all over the globe. high salinity water cools and sinks in N Atlantic then returns the the surface in the Indian and Pacific through upwelling.

Sea Breeze

During the day, land surfaces absorb and reflect heat faster than the ocean. Cooler air from the ocean moves inland to replace the warm air rising from the land.

Amplitude

Height of a wave.

Crest

Highest point of a wave.

Frequency

How many wave peaks pass a certain point per given time.

Tsunami

Long, wavelength waves that result from movements in Earth's crust. The wavelength determines the volume of water that comprises the wave. Causes include an earthquake, underwater volcano, or landslide. The devastation is caused not by the wave's height but by the huge volume of water that surges across the shore. Move extremely fast.

Trough

Lowest point of a wave.

Deep water

Most of Earth's ocean water is in the this zone, which begins at approximately 1,000 meters; therefore, most water in the ocean is close to freezing.

Coriolis Effect

Ocean currents at the surface are influenced by this. The effect of Earth's rotation on the direction of winds and currents.

Freezing Temperature

Temperature at which a liquid will start to change to a solid. The higher salt content in water results in lower freezing temperatures of that water.

Abyss

The deepest portions of the ocean basin (abyss comes from the Greek word for "bottomless"), excluding ocean trenches.

Wavelength

The distance between two corresponding parts of a wave.

Continental shelf

The edge of a continent where the water is relatively shallow.

Continent

The landmass surface where the water from the ocean meets at the shoreline.

Seafloor Spreading

The process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge

Upwelling

The process by which nutrients and energy resurface. Cold, nutrient-rich water rises from the deep ocean to the surface. Is caused when winds drive the surface waters away from an area. Can change weather patterns in an area.

Tides

The regular rise and fall of the ocean's surface influenced by the moon's gravity pulling on earth.

Boiling Point

The temperature at which a liquid changes to a gas. The higher salt content in water results in a higher boiling point temperature of that water.

Biosphere

composed of all the living things on Earth and their environments.

Ocean Salinity

highest where evaporation of water from the sea surface is strongest; salty water is denser than fresh water; saltier areas correspond to warmer areas.

Subduction Zone

in tectonic plates, the site at which an oceanic plate is sliding under a continental plate.

High Tide

the highest point on shore that the ocean reaches (occurs when the sun and moon are in line).

Low Tide

the lowest point on shore that the ocean reaches (occurs when the sun and moon are not in line).

Cryosphere

the portion of the Earth's surface where water is in solid form, including ice and snow.

Atmosphere

the protective layer of gases surrounding Earth.

Geosphere

the solid part of Earth including all rocks and minerals.

Hydrosphere

the water on or surrounding the surface of the globe, including the waters of the oceans and the water in the atmosphere.