Oceanography Notes

Abrasion

The mechanical wearing down of rock, soil, and surface materials through repetitive friction and impact, often caused by natural elements such as wind, water, and ice, leading to the gradual alteration of landscapes.

Breakwave

A dynamic ocean phenomenon characterized by the instability and subsequent collapse of incoming waves as they approach the shoreline, creating a turbulent surf zone that affects coastal erosion and marine life.

Coriolis Effect

The apparent deflection of moving objects, such as air currents and ocean currents, due to the Earth's rotation, which influences global weather patterns, ocean circulation, and the movement of storm systems.

Gyre

Large circular systems of ocean currents driven by wind patterns and the Earth's rotation, essential for regulating global climate, redistributing nutrients, and influencing marine ecosystems.

Longshore Current

A current that flows parallel to the shoreline, generated by waves breaking at an angle to the coast, which transports sediment and contributes to coastal erosion and deposition patterns.

Seawall

A man-made structure constructed along coastlines to protect against wave action, erosion, and storm surges, designed to absorb and reflect the energy of waves, thereby safeguarding coastal communities and infrastructure.

Submergent Coast

A coastal configuration formed when sea levels rise or land subsides, resulting in the inundation of coastal areas, which can lead to the development of features such as estuaries and submerged river valleys.

Surf

The zone of turbulent, churning water formed by breaking waves that approach the shore, where high energy interactions occur between air and water, shaping beach morphology and influencing coastal ecosystems.

Thermohaline Circulation

The large-scale circulation of ocean waters driven by differences in temperature (thermo) and salinity (haline), which plays a critical role in regulating climate by transporting heat and nutrients around the globe.

Upwelling

The process by which deeper, colder, and nutrient-rich waters rise to the ocean surface, often occurring along coastlines, which enhances biological productivity and supports diverse marine life.

Wave Height

The vertical distance measured from the crest (top) of a wave to its trough (bottom), an important factor in determining wave energy and its impact on coastal processes.

Wavelength

The horizontal distance between consecutive wave crests or troughs, which influences the speed, energy, and behavior of waves as they propagate through the water.

Wave of Oscillation

A type of wave that occurs in deep water where water particles move in circular orbits, allowing the wave energy to travel without the actual water mass moving significantly forward.

Wave of Translation

A wave type that occurs in shallow water, characterized by the forward movement of both energy and water, leading to the breaking of waves as they reach the shore.

Wave Period

The time interval between the passage of consecutive wave crests at a fixed point, which helps determine wave frequency and energy distribution in the ocean.

Wave Refraction

The bending of wave fronts as they approach shallow water, causing waves to change direction and concentrate energy on headlands while dissipating in bays.

Active Continental Margin

A geologically active region where oceanic and continental crust converge, often associated with tectonic activity including earthquakes, volcanic eruptions, and the formation of mountain ranges.

Aphotic Zone

The layer of the ocean that is devoid of sunlight, typically found at depths greater than 200 meters, where photosynthesis cannot occur and marine life adapts to complete darkness.

Biogenous Sediment

Sediments that are primarily composed of the remains of marine organisms, such as shells and coral, which contribute to the biological productivity and geological formation of seafloors.

Continental Margin

The zone of interaction between continental and oceanic crust, consisting of the continental shelf, slope, and rise, which serves as an important area for marine biodiversity and resource extraction.

Continental Rise

The gently sloping region at the base of the continental slope where sediments accumulate from the slope, forming an important transition zone between the continent and the deep-sea floor.

Continental Shelf

The submerged extension of a continent characterized by shallow waters, providing a rich habitat for marine life and significant resources, including fisheries and oil deposits.

Continental Slope

The steeply inclined seaward edge of the continental shelf that leads to the deep ocean, marked by dramatic changes in depth and often associated with sediment transport and geological hazards.

Deep-Ocean Trench

Narrow, elongated depressions in the ocean floor formed at convergent plate boundaries, where tectonic plates subduct and create some of the deepest parts of the Earth's oceans.

Graded Bedding

A sedimentary structure characterized by a gradual change in particle size, typically seen in sedimentary deposits formed by turbidity currents, indicating variations in energy levels during deposition.

Halocline

A stratified layer in ocean water characterized by a rapid change in salinity with depth, which can influence ocean circulation, marine life, and chemical processes.

Hydrogenous Sediment

Sediments that originate from the precipitation of dissolved minerals from seawater, including manganese nodules and phosphorites, contributing to the mineral composition of the ocean floor.

Intertidal Zone

The coastal area that is alternately submerged and exposed by tidal movements, featuring unique ecosystems that support specialized flora and fauna adapted to changing environmental conditions.

Mid-Ocean Ridge

A divergent plate boundary where new ocean floor is generated, characterized by volcanic activity and hydrothermal vents that support unique ecosystems reliant on chemosynthesis.

Oceanography

The comprehensive study of the ocean's physical, chemical, geological, and biological processes, essential for understanding marine environments, ocean dynamics, and their impacts on global climate.

Outgassing

The release of gases, such as water vapor, carbon dioxide, and other volatile compounds, from the Earth's interior, influencing the development of the atmosphere and the chemistry of oceans.

Passive Continental Margin

A stable region where the continental crust transitions gently into the oceanic crust, characterized by little tectonic activity, wide continental shelves, and significant sediment deposition.

Photic Zone

The upper layer of the ocean where sunlight penetrates, supporting photosynthetic life and driving primary productivity, typically extending to about 200 meters in depth.

Rift Valley

A landform created by the divergence of tectonic plates, characterized by a long, narrow depression, often associated with volcanic activity and geological significance.

Salinity

The concentration of dissolved salts in water, typically measured in parts per thousand (ppt), which influences the density, buoyancy, and ecological balance of marine environments.

Submarine Canyon

A deep, steep-sided valley carved into the seafloor, often formed by erosion from turbidity currents, which provides habitats for marine life and can influence sediment distribution.

Terrigenous Sediment

Sediments that are primarily derived from terrestrial sources, including weathered rock and soil, transported into the ocean by rivers, wind, and erosion processes.

Thermocline

A distinct layer in the ocean characterized by a rapid decline in temperature with depth, influencing marine life distribution and ocean circulation patterns.

Turbidite

A sedimentary deposit formed by turbidity currents that transport suspended sediments down the continental slope, contributing to the formation of deep-sea fans and geological features.

Turbidity Current

A fast-moving underwater flow of sediment-laden water, often triggered by disturbances such as earthquakes or sediment collapses, responsible for transporting materials across the sea floor.