Divisions of the Global Ocean 1. Atlantic second largest a) Average depth of 3.6 km 2. Pacific largest ocean and feature on Earth’s surface a) Contains more than ½ of ocean water on Earth b) Deepest ocean at 3.9 km 3. Indian is the 3 rd largest a) Average depth of 3.8 km 4. Southern Ocean a) Coldest ocean 5. Arctic Ocean Sea: smaller parts of ocean partially surrounded by land

Earth’s 5 Oceans

Properties of Ocean Water 1. Composition a) Salts: carried out by rivers, not returned to land when water evaporates b) Elements: chlorine, sodium, magnesium, sulfur, calcium, & potassium c) Dissolved gases: Nitrogen, oxygen, & carbon dioxide 2. Salinity: amount of dissolved salts in ocean water 1. Increases as temperature increases 2. Removal (evaporation) of water will increase salinity 3. Adding of water (rain, rivers) will decrease salinity

Properties of Ocean Water 3. Temperature a) Surface: temperature effected by sun, moving water underneath, & distance from the equator a) Temperature decreases as depth increases b) Thermocline: zone of rapid temperature change under surface water

Properties of Ocean Water 4. Density: effected by temperature & Salinity 5. As Depth Increases so does the Pressure 6. Color: determined by the way water absorbs or reflects sunlight

Waves The movement that carries energy through ocean. Caused by: Wind Tides Earthquakes Volcanic Eruptions

Parts of a Wave Crest – highest point of a wave Crest – highest point of a wave Trough – lowest point of a wave Trough – lowest point of a wave Wave Height – vertical distance between the crest and the trough Wave Height – vertical distance between the crest and the trough Wavelength – horizontal distance between two crests or two troughs Wavelength – horizontal distance between two crests or two troughs

Still Water Wave Parts Trough Wave Height Crest Wavelength

Wave Movement When a wave passes through the ocean, individual water molecules move up and down but they do not move forward or backward. When a wave passes through the ocean, individual water molecules move up and down but they do not move forward or backward.

Wave Movement When a wave breaks against the shore, the crest outruns the trough and the crest collapses. When a wave breaks against the shore, the crest outruns the trough and the crest collapses. Called a breaker. Called a breaker. In this case, water does move forward and backward. In this case, water does move forward and backward.

Tides Caused by the rise and fall of sea level 4 tides occur daily: 2 high tides & 2 low tides Tidal Range: Difference between high and low tide Intertidal Zone: area that high tide covers and low tide exposes Period when sea level rises: flood tide Period when sea level falls: ebb tide Period in between: slack water

Sun Tidal influence is only 46% that of the Moon Due to the much greater distance the gravitational force is reduced Sun Tidal influence is only 46% that of the Moon Due to the much greater distance the gravitational force is reduced

Ocean Currents Surface Currents: Currents mainly in the top 100 to 200m of the ocean Driven by Earth’s wind systems Northern Hemisphere Trade winds and Westerlies blow the Gulf Stream Deep currents: Caused by differences in density caused by the temperature and salinity of ocean water Moves slowly in deep ocean Cold, dense water sinks at the poles After sinking these water masses slowly move away from the poles Eventually return to the surface through upwelling

Surface Currents Upwelling: upward motion of cold water occurs when surface water is moved offshore Downwelling: warm surface water piles up along the shore and sinks

Deep Water Currents Thermohaline Circulation: ocean conveyer belt Dominant driving force is difference in density caused by salinity and temperature As water freezes into ice, the water that does not freeze becomes much more saline. Water that has a high salt content is more dense and as a result will sink. Cold water is more dense than warm water and will sink