Oceanography Exam Review

Capillary Waves: Very small waves, often caused by light winds.
Wind Waves: Generated by wind on the surface of the water.
Seiche Waves: Standing waves in an enclosed or partially enclosed body of water.
Internal Waves: Form below the surface, occurring within a fluid medium, like ocean water layers.
Tsunami Waves: Large waves typically caused by seismic activity, moving quickly across the ocean.
Tidal Waves: Waves generated by the gravitational pull of the moon and sun, affecting the tides.

Wind Speed: The velocity of wind plays a crucial role in wave generation.
Duration: The length of time the wind blows impacts wave height and size.
Fetch: The distance over water that wind blows in a single direction, influencing energy transfer to waves.

Height: Vertical distance from the crest (top) to the trough (bottom).
Wavelength: Distance between successive wave crests or troughs.
Period: Time interval between two successive crests passing a fixed point.
Steepness: Ratio of wave height (H) to wavelength (L), defined as $ext{Steepness} = rac{H}{L}$ .
Speed: Rate at which a wave travels, calculated through the formula $ext{Speed} = rac{L}{T}$ where L is wavelength and T is period.
Frequency: The number of waves passing a point per unit time, inversely related to the period (Frequency = 1/Period).

Occurs when deepwater waves reach shallow water near the shore.
Four Main Types of Surf:
- Spilling Waves: Waves that break gradually, spilling water down their front as they approach the shore.
- Plunging Waves: Waves that break suddenly, resulting in a curling shape as they crash onto shallow waters.
- Collapsing Waves: Waves that exhibit characteristics of both spilling and plunging waves but noticeably collapse closer to the shore.
- Surging Waves: Waves that surge forward without breaking, typically found on steep beaches.

When two waves interact, they may produce:
- Constructive Interference: Waves combine to make a bigger wave.
- Destructive Interference: Waves combine and cancel each other out, resulting in a smaller wave.
- Mixed Interference: A combination of both constructive and destructive interference.

Rogue Waves: Unexpectedly large and dangerous waves that can appear in the ocean.
Tsunamis: Classified as shallow water waves, created by seismic activity, traveling quickly across oceans.
Storm Surge: Caused by wind and pressure changes during storms, leading to anomalous increases in sea level.

Causes of Tides:
- Centripetal Forces: Resulting from gravitational attraction between the Earth and moon.
- Centrifugal Forces: Resulting from the Earth’s rotation.
These forces do not act in the same plane and balance each other at the Earth’s center.
Earth's Rotation: The spinning of the Earth causes shifts in tides creating rise and fall in sea levels.
Solar Influence: The sun affects tides but to a lesser degree than the moon.
- Can constructively combine with lunar effects to create spring tides, which are the highest and lowest tides.

Semidiurnal Tides: Two high tides and two low tides each day.
Diurnal Tides: One high tide and one low tide each day.
Mixed Tides: A combination of high and low tides, with varying heights and time intervals.
Tidal Bores: A phenomenon where an incoming tide forms a wave that travels up narrow bays or rivers.
Rip Currents: Dangerous currents that flow away from shore, often formed by varying wave heights.

Sea levels have fluctuated through Earth's history due to climatic changes.
Two Main Processes Affecting Sea Levels:
- Isostasy: Variations in land height and buoyancy due to sediment load and geological activity.
- Eustasy: Changes in sea level caused by variations in water volume and temperature.

Climate change is accelerating sea level rise, posing risks to coastal regions.
Delaware: Entire state is primarily coastal, highly affected by these changes.

Emerging Shorelines: Areas experiencing uplift, reducing sea levels or both; commonly observed on the Pacific Coast.
Submerging Shorelines: Areas where land is subsiding or sea levels are rising; typically observed on the Atlantic Coast.

Backshore: The area above the high tide line.
Foreshore: The area between the high and low tide lines.
Shoreline: The interface between land and water.
Nearshore: The area just offshore, often affected by wave actions.
Offshore: Areas further away from the shoreline where waves still have an impact.

Sand troughs located underwater that affect wave actions and sediment transport.

Beaches are formed from local materials and are dynamic, constantly influenced by sediment movement.
Sediment Size: Influences the slope of the beach; finer sands tend to produce gentler slopes.

Primarily found on the Pacific Coast, where headlands focus wave energy.
- Process: Cracks form caves that eventually grow, erode, and collapse, leading to the formation of rock stacks.

Found on the East and Gulf Coasts; characterized by features formed from sand deposits such as:
- Spit: A sandy beach that extends out into the water, formed by sediment deposition.
- Barrier Islands: Coastal islands formed from wave actions that protect the mainland from erosion.
- Tombolo: A landform connecting an island to the mainland.

Longshore Current: A current that flows parallel to the shore.
Longshore Drift: The movement of sand particles along the beach due to wave action.
Swash and Backwash: The uprush and retreat of water on the beach, respectively, creating a triangular shape in the pattern of sand movement.

Coasts are in constant motion due to geological and climatic factors.
Efforts to protect infrastructure include:
- Groins/Jetties: Structures built to inhibit sand movement and reduce erosion.
- Seawalls: Barriers constructed to protect shorelines from wave impacts.
- Renourishment: The process of adding sand to eroding beaches;
- Negative Effects: These protective measures can affect the natural erosion and deposition processes negatively.

Important ecological zones that serve as nursery habitats and refuge for many species.
Function as buffer zones against pollution and other environmental impacts.
- Types include:
- Intertidal Wetlands: Areas that experience periodic flooding from tides.
- Freshwater Wetlands: Areas dominated by freshwater.
- Saltwater and Mangrove Wetlands: Coastal ecosystems that flourish in saline conditions.

Concerns regarding the degradation of wetlands due to urban development and environmental changes.

Defined as a partially enclosed area along the coast where freshwater from land intersects with saltwater from the ocean, resulting in unique ecological and chemical characteristics.
Pollution and Eutrophication:
- Point Source Pollution: Contaminants that can be traced back to a single source, such as a pipe.
- Non-Point Source Pollution: Diffuse contamination from multiple sources, such as agricultural runoff.
- Eutrophication: Excess nutrients, usually from runoff, leading to algal blooms and oxygen depletion in water bodies, resulting in dead zones where aquatic life cannot survive.