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The Dynamic OceanSection 4

By Ben Stone, Lindsey Kuhn, Alexis Ryan, Alec Walker, Christian Assimus

America's Pacific and Atlantic coasts!!! (California girls vs Boston Boys!!!)

•Basic geological differences.o The nature of shoreline erosion problems

along America's Pacific and Atlantic coasts are very different.

• Most development along the Atlantic and Gulf coasts (coast - land adjacent to sea) occurs on barrier islands, they receive the full force of major storms

• Most of the Pacific coastline (coastline - outline of the coast) is characterized as narrow beaches backed by steep cliffs and Mt. ranges.

•Basic geological differences.

• Most of the Pacific coast is characterized as narrow beaches backed by steep cliffs and Mt. ranges.o A major problem with the pacific shoreline is

that the beaches are narrowing caused by irrigation and flood-control dams that interrupt natural flow of sand to the coast.

America's Pacific and Atlantic coasts!!! (California girls vs Boston Boys!!!)

• A classification of coast commonly used is based upon the height of the sea

• Coasts that often exhibit wave-cut cliffs and marine terraces and develop either because an area experiences uplift or a result of a drop in sea level- Emergent Coast

• Wave-Cut Cliffs- A cliff formed along a coast by the undercutting action of waves and currents

• Wave-Cut Platform- a relatively flat, bench like surface

Emergent and Submergent Coast

Emergent and Submergent Coast

•Submergent Coast- commonly display drowned river mouths called Estuaries that are created when sea level rises or the land adjacent to sea subsides

•Marine Terrace- a wave- cut platform that is uplifted above sea level by tectonic forces

Submergent Coastline

Emergent Coastline

Tides - the increase and decrease in the elevation of the ocean surface at an exact place

- caused by gravitational attraction of the Moon and partly by the Sun

* Spring Tides - when the Moon and Sun are aligned (new and full moon), the tides become higher and lower

* Neap Tides - when the Moon and Sun are at right angles (first and third quarter) , the daily tidal range is less

- Factors that influence tides: tidal patterns, tidal currents, shape of the coast, weather/wind, etc.

Factors that Influence Tides

• You can find the three main tidal patterns anywhere in the world.

• Diurnal tidal pattern- it shows one high and one low tide a day

• Semidiurnal tidal pattern- it shows two high and two low tides every day about the same height

• Mixed tidal pattern- it shows two high and two low tides each day displaying different heights

Three main tidal patterns

• Tidal Currents- Horizontal movements of water that accompany the rise and fall of tides. These water movements are induced by tidal forces and important in coastal areas.

• Tidal Flats- The areas that are affected by the advancing and retreating of tidal currents. Depending on the nature on the coastal zone, tidal flats vary from narrow strips seaward of the beach to zones that may extend for several kilometers

Tidal Currents

Tidal Currents

•When tidal currents slow down after emerging from narrow inlets, they deposit sediment that may eventually create tidal deltas. They form after the tidal current moves rapidly through an inlet. As the current emerges into more open waters from the narrow passage, it slows and deposits its load of sediment.

Works Cited

Tarbuck, Edward J., Frederick K. Lutgens, and Dennis Tasa. Earth Science.

11th ed. Upper Sadle River, New Jersey: Pearson Prentice Hall, 2006. Print.