Chapter 15

These flashcards cover key terms and definitions from the oceanography lecture notes to assist in studying for the exam.

Lithosphere

The rigid outer layer of the Earth, comprising the crust and upper mantle.

Isostasy

The state of gravitational equilibrium between the Earth's lithosphere and asthenosphere, allowing them to float at different elevations.

Bathymetry

The study of underwater depth of ocean floors or lake beds.

Seafloor Spreading

The process by which new oceanic crust forms as magma rises to the surface at mid-ocean ridges.

Mid-Ocean Ridge

An underwater mountain range formed by plate tectonics.

Transform Fault

A type of fault in which two tectonic plates slide past each other horizontally.

Subduction Zone

A geologic feature where one tectonic plate moves under another, often forming deep oceanic trenches.

Continental Shelf

The submerged border of a continent that slopes gently and is usually covered by shallow water.

Continental Slope

The steep gradient between the continental shelf and the deep ocean floor.

Abyssal Plain

A flat, deep ocean floor region typically found at depths of 4,000 to 5,000 meters.

Seamount

An underwater mountain formed by volcanic activity.

Salinity

The concentration of salt in water, expressed in parts per thousand.

Tide

The periodic rise and fall of sea level due to the gravitational forces of the Moon and Sun.

Thermocline

A layer in the ocean characterized by a rapid change in temperature with depth.

Wave Height

The vertical distance between the crest and trough of a wave.

Crest

The highest point of a wave.

Trough

The lowest point of a wave.

Wavelength

The distance between two successive crests or troughs of a wave.

Longshore Drift

The movement of sediment along a coast due to wave action.

Barrier Island

A coastal landform that runs parallel to the shore and protects the mainland from wave action.

Estuary

A coastal area where freshwater from rivers meets and mixes with saltwater from the ocean.

Coral Reef

An underwater ecosystem formed by colonies of coral polyps, requiring warm, shallow water.

Ocean Gyre

A large system of circulating ocean currents, driven by wind, the Earth’s rotation, and landmasses.

Coriolis Effect

The deflection of moving objects, such as air and water, due to the Earth's rotation.

Upwelling

The process by which deep, nutrient-rich water rises to the surface, often enhancing biological productivity.

Turbidity Current

A fast-moving current of water that carries a mixture of sediments and water down the slope of the seafloor.

Dead Zone

A region of water with low oxygen levels, where marine life cannot survive.

Rogue Wave

An unexpectedly large and dangerous wave that can occur in the ocean.

Rip Current

A powerful current of water that pulls away from the shore, often causing swimmers to drift out to sea.

Storm Surge

The rise in seawater level during a storm, resulting from strong winds and low atmospheric pressure.

Erosion

The process by which natural forces remove and transport soil and rock.

Sedimentation

The process of deposition of sediments, often leading to the formation of new landforms.

Dune

A hill of sand formed by the wind, typically found in desert or coastal areas.

Mangrove

A coastal ecosystem characterized by salt-tolerant trees and shrubs.

Tidal Flat

A coastal wetland that is flooded by tides, consisting of mud and silt.

Coastal Erosion

The loss of coastal land due to wave action and other natural processes.

Backwash

The motion of water returning to the sea after a wave has broken on the shore.

Berm

A flat, raised area at the top of a beach, formed by the deposition of sand.

Sea Stack

A steep and often isolated vertical column of rock in the sea, formed by erosion of a headland.

Lagoon

A shallow body of water separated from a larger sea by barrier islands or reefs.

Delta

A landform where sediment is deposited at the mouth of a river, creating new land.

Salinity Variability

The changes in the concentration of salt in ocean water due to factors like evaporation and precipitation.

Hurricane

A tropical cyclone with winds exceeding 119 km/h, characterized by a rotating vortex.

Cyclone

A large-scale air mass that rotates around a strong center of low atmospheric pressure.

Typhoon

A tropical storm in the northwestern Pacific, equivalent to a hurricane.

Saffir-Simpson Scale

A scale used to categorize hurricanes based on their wind speed.

Storm Damage

Destruction caused by strong winds, storm surge, and heavy rainfall during a hurricane.

Floodplain

An area of land adjacent to a river prone to flooding during periods of high water.

Climate Change

Long-term alteration in temperature and typical weather patterns in a place.

El Niño

A climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific.

Tsunami

A series of ocean waves caused by disturbances such as earthquakes or volcanic eruptions.

Hydrothermal Vent

An opening in the sea floor that emits heated water rich in minerals.

Deep-Sea Trench

A deep depression in the ocean floor, often where subduction occurs.

Plankton

Microscopic organisms that float or drift in water, serving as a primary food source in marine ecosystems.

Pelagic Sediment

Fine-grained sediment that settles to the ocean floor from plankton and other particles.

Marine Biodiversity

The variety of species and ecosystems in ocean environments.

Upwelling Zones

Areas in the ocean where nutrient-rich water rises to the surface, promoting high biological productivity.

Nutrient Cycling

The movement and exchange of organic and inorganic matter back into the production of living matter.

Hydrological Cycle

The journey water takes as it circulates from the land to the sky and back.

Coastal Geomorphology

The study of the landforms and processes that shape the coastal environment.

Aquifer

A layer of permeable rock that can contain or transmit groundwater.

Permeability

The ability of a material to transmit fluids, often relevant in geology and hydrology.