Oceanography Overview

1. Oceanography: Polar Views of the Earth 71% of Earth is covered with oceans

Land-Ocean Distribution Which latitudes have the most land? Which latitudes have the least land?

2. Seawater Properties Salinity –Measure of dissolved salts in water –Grams dissolved per 1000 grams water –Average salinity is 35 grams of salt per 1000 grams of water 35% Salinity –Measure of dissolved salts in water –Grams dissolved per 1000 grams water –Average salinity is 35 grams of salt per 1000 grams of water 35% In comparison….(parts per thousand) Distilled Water0 Lake Erie2-3 Ocean35 Great Salt Lake45 Dead Sea250 In comparison….(parts per thousand) Distilled Water0 Lake Erie2-3 Ocean35 Great Salt Lake45 Dead Sea250

Dissolved elements in Ocean Water Chloride and Sodium are the 2 main elements dissolved in ocean water

3. Sunlight penetration The blue spectrum of sunlight travels the best in water, therefore the oceans look blue. The top layer of the ocean is warmer due to the penetration of sunlight. The amount of sunlight that penetrates the ocean affects life in the ocean zones.

3. Temperature V/S Depth Mixed layer Thermocline Deep layer The thermocline is the layer in the ocean where the temperature dramatically decreases. It separates the mixed layer at the top from cold deep layer below. Remember: Convection currents help transfer heat in our oceans!

4. Ocean currents Ocean currents exist at many levels in the ocean: surface currents, mid-level currents, and deep sea currents. Ocean currents help circulate the Sun’s heat and important nutrients for ocean life. Ocean currents exist at many levels in the ocean: surface currents, mid-level currents, and deep sea currents. Ocean currents help circulate the Sun’s heat and important nutrients for ocean life.

5. Upwelling occurs when cold, nutrient rich water rises to replace the warmer, nutrient depleted water. Because cold water is more dense, upwelling is driven by the wind. It pushes the warm water out of the way, so the cold water can rise. Upwelling is important for the fishing industry because it allows nutrients (food) to rise for the fish to eat and grow.

El Nino Conditions cause: Loss of fish/fishing Warmer surface water Increase in storms (warmer water= more evaporation)

6. Coral reefs Coral reefs are underwater structures of calcium carbonate made by corals (living organisms) Ancient coral reefs may have formed the present day limestone The great barrier reef in Australia is the largest living structure on Earth Coral reefs are underwater structures of calcium carbonate made by corals (living organisms) Ancient coral reefs may have formed the present day limestone The great barrier reef in Australia is the largest living structure on Earth They are endangered and sensitive. They can be destroyed by temperature changes, pollution, and by being hit/struck.

Formation of a coral atoll Coral atolls form from sunken volcanic islands They are just one type of coral reef The enclosed water is called a lagoon. Coral atolls form from sunken volcanic islands They are just one type of coral reef The enclosed water is called a lagoon.

Most Corals only survive in shallow, warm water 79°- 81°F. Bleaching Coral Bleaching occurs when the corals die. The colors fade away, but the calcium carbonate “shell” remains.