Oceanography

What is a sand budget?

The balance between sand added to and removed from a beach system.

What are the main parts of a beach?

Berm, dune, foreshore, backshore, longshore bar, and trough.

What are barrier islands?

Long, narrow islands parallel to shore that migrate over time.

What are coastal arches?

Eroded rock structures formed by wave action.

What causes sea cliffs?

Waves eroding the base of coastal rock or sediment.

What causes beach and coastal erosion?

Sea level rise, storms, waves, longshore currents, and human activities.

What are responses to beach erosion?

Seawalls, groins, jetties, beach nourishment, and managed retreat.

What are the major causes of sea level rise?

Thermal expansion of seawater and melting of land ice.

What is wave refraction?

The bending of waves as they approach shallow water, causing uneven erosion.

What is longshore transport?

The movement of sediment along shore by waves approaching at an angle.

What are coastal oceans?

Shallow marine environments influenced by land, tides, and river input.

What are the four types of estuaries?

Drowned river valleys, fjords, bar-built, and tectonic estuaries.

What are wetlands?

Coastal marshes and mangroves with water-saturated soils.

Why are wetlands important?

Provide habitat, storm protection, erosion control, and pollution filtering.

What are major types of marine pollution?

Plastics, oil, chemicals, sewage, nutrients, and noise.

What are the thermal properties of seawater?

High heat capacity, slow temperature change, and thermal inertia.

What affects seawater density?

Temperature, salinity, and pressure.

What is seawater pH?

Average ~8.1; slightly basic.

How can salinity change?

Evaporation, precipitation, river input, sea ice formation or melting.

What is a thermocline?

A depth layer with rapid temperature change.

What is a halocline?

A depth layer with rapid salinity change.

What is a pycnocline?

A depth layer with rapid density change.

What is the layered ocean structure?

Mixed layer, thermocline, and deep ocean.

What causes Earth's seasons?

The tilt of Earth's axis, not distance from the sun.

How is solar energy distributed unevenly?

More direct sunlight at the equator and less at poles.

What is albedo?

The reflectivity of Earth's surface.

What is global warming?

Long-term increase in average global temperatures due to greenhouse gases.

What is ocean acidification?

Increased CO2 dissolving in seawater, lowering pH.

What is the carbonate buffering system?

Chemical reactions that help stabilize ocean pH.

What are storms in oceanography?

Hurricanes, typhoons, and cyclones formed by warm water and low pressure.

What is El Niño?

Weak trade winds → warm water shifts east → global climate disruptions.

What is La Niña?

Strong trade winds → cooler eastern Pacific → enhanced upwelling.

What drives atmospheric circulation?

Uneven heating of Earth's surface.

What are wind belts?

Trade winds, westerlies, and polar easterlies.

What are circulation cells?

Hadley, Ferrel, and Polar cells.

What is atmospheric pressure?

The weight of air; high pressure sinks, low pressure rises.

What is cyclonic flow?

Counterclockwise in the Northern Hemisphere, around low pressure.

What is anticyclonic flow?

Clockwise in the Northern Hemisphere, around high pressure.

What are climate belts?

Zones defined by temperature and precipitation.

How does the Coriolis effect influence winds?

Deflects winds right in NH, left in SH.

What causes surface currents?

Wind, Coriolis effect, and continent placement.

What are Eastern Boundary Currents?

Cold, shallow, slow currents (e.g., California Current).

What are Western Boundary Currents?

Warm, deep, fast currents (e.g., Gulf Stream).

What is upwelling?

Rising of cold, nutrient-rich water to the surface.

What is downwelling?

Sinking of surface water due to convergence.

What are deep currents?

Dense, cold, salty currents that form thermohaline circulation.

What is a gyre?

Large circular surface current system in ocean basins.

What are geostrophic currents?

Currents formed by the balance of pressure gradient and Coriolis effect.

What is Ekman transport?

Net water movement ~90° to the wind direction.

What are the main types of waves?

Wind waves, swell, tsunamis, and tides.

What is the motion of a wave?

Orbital motion decreasing with depth.

What is the wave equation (deep-water)?

Speed = wavelength / period.

How are waves generated?

Wind speed, duration, and fetch.

What is wave celerity?

The speed of a wave.

What are the main wave properties?

Wavelength, period, height, and speed.

What causes tsunamis?

Underwater earthquakes, landslides, or volcanic eruptions.

What causes tides?

Gravitational pull of the moon and sun + Earth's rotation.

What are spring tides?

Largest tidal range; occur during new and full moon.

What are neap tides?

Smallest tidal range; occur during quarter moons.

What is a diurnal tide?

One high and one low tide per day.

What is a semidiurnal tide?

Two equal high and low tides per day.

What is a mixed tide?

Two high and two low tides of unequal height per day.