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Questions and Answers
What determines wave height?
What happens to the circular motion of water particles as depth increases?
What is wave base defined as?
How does fetch influence wave generation?
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During strong storms like hurricanes, how does the wave base change?
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What is the process called when longer wavelengths travel faster and arrive first at a distant shore?
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Which type of interference occurs when crests align with crests and troughs align with troughs, leading to increased wave height?
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What happens to waves as they approach the shore and encounter shallow water?
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Which zone of the shoreline is defined as the area where the waves break?
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What feature develops in the backshore zone due to onshore winds blowing sand?
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What is the primary cause of the longshore current?
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Which statement about emergent coasts is true?
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What is a common way to manage the buildup of sand around harbors?
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What distinguishes rip currents from undertow?
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Which feature is associated with submergent coasts?
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What are the primary geological conditions under which tidal flat deposits formed in the Precambrian strata of the Big Cottonwood Formation?
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How do groins function differently from jetties in coastal management?
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What is the result of constructing breakwaters along a coastline?
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What is the primary cause of submarine canyons forming at the mouths of large river systems?
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How do turbidity flows contribute to the erosion of submarine canyons?
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What is the primary characteristic of salt pans in tidal flats?
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Which of the following statements about ocean currents is accurate?
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What typically happens to sand when a groin is constructed on a beach?
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In what way does human intervention typically disrupt coastal ecosystems?
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What role do dunes and vegetated areas on tidal flats serve?
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Study Notes
Waves and Wave Processes
- Wind energy is transferred to water through friction, creating waves.
- Waves move as individual water particles that oscillate in a circular motion.
- Wave height is determined by wave energy.
- Wave base is the depth at which water ceases to be disturbed by waves.
- Wave base is approximately half the wavelength.
- Fair-weather wave base is shallower than storm wave base.
- Wave energy is influenced by wind velocity and fetch, the distance the wind blows.
- Wave dispersion occurs when longer wavelengths travel faster than shorter wavelengths, resulting in a sorting process.
- Wave interference occurs when wave trains from different directions interact.
- Constructive interference occurs when wave crests align, amplifying the wave height.
- Destructive interference occurs when wave crests align with troughs, canceling each other out.
- Waves slow down as they approach a shoreline due to friction with the seafloor.
- Wave height increases as waves approach the shore, resulting in breakers.
- Tsunamis are large waves generated by underwater events such as earthquakes and volcanic eruptions.
- Tsunamis are characterized by long wavelengths and low wave heights in the open ocean, but increase significantly as they approach the shore.
Shoreline Features
- Coastlines are dynamic interfaces between land and sea, influenced by erosional and depositional processes.
- The littoral zone is the shifting interface between water and land at the shoreline.
- Shorelines are divided into five zones: offshore, nearshore, surf, foreshore, and backshore.
- The offshore zone is below water, but is geologically active due to turbidity currents.
- The nearshore zone is affected by waves and includes the shoreface, which is divided into upper and lower segments.
- The surf zone is where waves break.
- The foreshore zone is periodically wet and dry due to waves and tides.
- The backshore zone is always above sea level.
- Dunes form in the backshore zone due to onshore winds.
Wave Refraction, Longshore Currents and Longshore Drift
- Wave refraction occurs when waves approach the shoreline at an angle and slow down in shallower water, causing the wave crests to bend.
- Longshore currents are created by the slight angle between the swash (wave moving up the beach) and backwash (water flowing back down).
- Longshore drift is the movement of sand along the shore due to longshore currents.
- Spits and baymouth bars form when longshore drift deposits sand in bays and inlets.
- Jetties are structures built to deflect sand and keep harbors open.
- Rip currents are strong currents that flow away from the beach.
- Undertow is a current that flows beneath approaching waves and is strongest in the surf zone.
Emergent and Submergent Coasts
- Emergent coasts occur where sea levels fall relative to land.
- Submergent coasts occur where sea levels rise relative to land.
- Features of emergent coasts include sea cliffs, headlands, wave-cut platforms, stacks, and tombolos.
- Features of submergent coasts include flooded river mouths, fjords, barrier islands, lagoons, estuaries, and tidal flats.
- Tidal flats are areas along the coast that are alternately flooded and exposed by tides.
- Lagoons are bodies of water partially separated from the ocean by spits or barrier islands.
- Estuaries are lagoons where fresh water flows into the area, creating brackish water.
Human Impacts on Coastal Beaches
- Humans impact coastal beaches through development and efforts to manage erosion.
- Structures such as jetties, groins, and breakwaters are built to mitigate erosion and protect harbors.
- Dams trap sand from rivers, reducing sediment supply to beaches.
- Beach nourishment involves replenishing beaches with sand from other areas.
- Breakwaters can create tombolos behind them as longshore drift is interrupted.
Submarine Canyons
- Submarine canyons are deep, narrow canyons located on continental shelves.
- They are typically formed at the mouths of large rivers or by slumps and flows of sediment.
- Turbidity flows are underwater landslides that can erode and deepen submarine canyons.
Currents and Tides
- Ocean currents are driven by global winds and water density.
Ocean Currents and Earth's Heat Engine
- Ocean currents distribute heat absorbed by the ocean from solar energy.
- Water has a high specific heat, meaning it takes a lot of heat to change its temperature.
- Oceans, covering 71% of the Earth's surface, absorb a lot of heat with little temperature change.
Surface Currents
- The Earth's rotation and the Coriolis effect influence ocean currents.
- Large circular currents called gyres are driven by atmospheric circulation.
- Gyres rotate clockwise in the northern hemisphere and counterclockwise in the southern hemisphere due to the Coriolis Effect.
- Western boundary currents flow from the equator toward the poles carrying warm water and contribute to local climate.
- Eastern boundary currents return cold water toward the equator along the western coasts.
- Western boundary currents and eastern boundary currents significantly affect the climate of nearby lands.
Deep Currents
- Density of seawater is determined by temperature and salinity.
- Cold, denser water sinks to become the ocean's deep water, a process called thermohaline circulation.
- Thermohaline circulation connects the world's deep ocean waters.
- It brings nutrients to marine life and is sometimes referred to as the global conveyor belt.
Tides
- Caused by the gravitational effects of the Sun and Moon on the oceans.
- The Moon's gravitational influence on tides is dominant due to its proximity to Earth.
- Tidal range depends on the configuration of the Moon and Sun with respect to the Earth's orbit and rotation.
- Spring tide occurs when the Sun, Moon, and Earth align, resulting in a maximum tidal range.
- Neap tide occurs when the Moon and Sun are at right angles to the Earth, resulting in the lowest tidal range.
- Three types of tidal patterns: diurnal, semidiurnal, and mixed.
- Tidal phases are determined by bathymetry.
- Extreme tidal ranges occur in narrow restrictive zones that funnel tidal energy.
Shoreline Processes
- Waves, currents, and tides are the main agents that shape shorelines.
- Most coastal landforms result from moving sand via longshore drift and long-term sea level changes.
- The shoreline is divided into five zones.
- Processes at the shoreline are called littoral processes.
- Longshore drift is a process that moves sand along the coasts.
- When the longshore current deposits sand, it can accumulate, creating a spit or barrier called a baymouth bar.
- Emergent coasts are created by sea levels falling, while submergent coasts are caused by sea levels rising.
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Description
Explore the fascinating world of waves and their processes in this quiz. Understand how wind energy transfers to water, the mechanics of wave height, base, and the influence of environmental factors. Test your knowledge on concepts like wave dispersion, interference, and the effects of shoreline interaction.
