Chapter 15 Dynamic Ocean Homework

A friend wants to purchase a vacation home on a barrier island. If consulted, what advice would you give your friend?

Barrier islands are fragile, buildings have endangered the environment for the barrier islands. There is a lot of property damage from hurricanes. I would suggest just going for a vacation from time to time but not own property.

In general, which regions are experiencing higher sea levels? Lower sea levels?

Coastal regions are expecting higher sea levels, and polar regions are expecting lower sea levels.

What observable features would lead you to classify a coastal area as emergent?

Wave-cut cliffs and marine terraces. Uplift of the land and/or drop in sea level.

How is a mixed tidal pattern different from a semidiurnal tidal pattern?

-Mixed tidal pattern: 2 high and 2 low waters every day Large difference in high and/or low water heights Along Pacific Coast of USA -Semidiurnal tidal pattern: 2 high and 2 low tides every tidal day Little difference in high and low water heights Along Atlantic Coast of USA

Name the five subtropical gyres and identify the main surface currents in each.

-North Pacific Gyre: North Equatorial Current, Kuroshio Current, North Pacific Current, California Current -South Pacific Gyre: South Equatorial Current, Peru Current, West Wind Drift, East Wind Drift -North Atlantic Gyre: North Atlantic Drift, Labrador Current, E. Greenland Current, Norwegian Current, Gulf Stream, North Atlantic Current, Canary Current, North Equatorial Current -South Atlantic Gyre: Brazil Current, South Equatorial Current, Benguela Current -Indian Ocean Gyre: Agulhas Current, West Australian Current, North Equatorial Current, South Equatorial Current, Leeuwin Current

List three ways barrier islands form.

-Originated as spits that were separated from the mainland by wave erosion or rise in sea level. -When turbulent waters bring up sand that had been set at the bottom. -Former sand dune ridges along the shore when sea level was lower.

What term is applied to the wall-like structures that extend into the water? What is their purpose?

Groins: barriers built at a right angle to the beach, designed to trap sand.

How long does it take to go from high tide to low tide? High tide to high tide?

High to low: ~6 hours, High to high: ~12 hours

If wastage (melting and calving) of the Greenland Ice Sheet were to dramatically increase, how would the salinity of the adjacent North Atlantic be affected? Speculate about how this might influence thermohaline circulation.

If the Greenland Ice Sheet started to melt dramatically, the salinity would decrease because that would be adding water to the ocean. Sea level would rise, damaging the homes on the coastal regions, refugees, and coastal economic activity. It would also change the water circulation which will affect weather. Heat and rainfall would be altered as well.

What is the effect of rising sea level?

It will possibly flood bridges.

What factors would control the time of high tide?

Shape of the coastline, ocean basin, and water depth.

Describe the process of coastal upwelling. Why is an abundance of marine life associated with these areas?

The rising of cold water from deeper layers. It brings up nutrients to the surface.

How do the speed, length, and height of a wave change as the wave moves into shallow water and breaks?

The speed and length of a wave will decrease and the wave's height will grow slowly until it gets too steep and collapses.