OceansOceans

CuesCues World OceansWorld Oceans SeasSeas Properties of Ocean WaterProperties of Ocean Water ElementsElements Salinity Salinity SourcesSources Salinity LevelsSalinity Levels GasesGases TemperatureTemperature Ocean FloorOcean Floor Edges of ContinentsEdges of Continents Study the Ocean FloorStudy the Ocean Floor Oceanographer Oceanographer

The World’s OceansThe World’s Oceans

71% of the Earth’s surface is covered 71% of the Earth’s surface is covered by ocean water.by ocean water.

The oceans contain 97% of the The oceans contain 97% of the earth’s water.earth’s water.

All the oceans and seas are actually All the oceans and seas are actually one continuous body of water.one continuous body of water.

OceansOceans

The oceans are the Atlantic, Pacific, The oceans are the Atlantic, Pacific, Indian. Arctic and Southern.Indian. Arctic and Southern.

The Pacific Ocean is the largest The Pacific Ocean is the largest ocean.ocean.

The area and volume of the Pacific The area and volume of the Pacific Ocean are greater than the Atlantic Ocean are greater than the Atlantic and Indian combined.and Indian combined.

SeasSeas

A sea is a part of an ocean that is A sea is a part of an ocean that is nearly surrounded by water.nearly surrounded by water.

The Mediterranean, Arctic and Black The Mediterranean, Arctic and Black Sea are really part of the Atlantic Sea are really part of the Atlantic Ocean.Ocean.

Properties of Ocean WaterProperties of Ocean Water

Ocean water is a mixture of gases Ocean water is a mixture of gases and solids dissolved in pure water.and solids dissolved in pure water.

Oceanographers believe oceans Oceanographers believe oceans contain all the natural elements on contain all the natural elements on Earth.Earth.

85 of 90 have been found in the 85 of 90 have been found in the ocean.ocean.

Major Elements in the OceanMajor Elements in the Ocean

Ocean water is 96% pure water.Ocean water is 96% pure water. Chlorine (1.9) and sodium (1.1) make Chlorine (1.9) and sodium (1.1) make

up the next largest concentration of up the next largest concentration of elements.elements.

Sodium chloride is table salt.Sodium chloride is table salt.

SalinitySalinity

Salinity describes the amount of Salinity describes the amount of dissolved water in the ocean.dissolved water in the ocean.

Salinity is expressed in parts per Salinity is expressed in parts per thousand.thousand.

The salinity level of the ocean is The salinity level of the ocean is expressed in parts per thousand. expressed in parts per thousand.

The average salinity of ocean is 35 The average salinity of ocean is 35 parts per thousand.parts per thousand.

Sources of Salt in the OceanSources of Salt in the Ocean

When volcanoes erupt, rock When volcanoes erupt, rock materials and gases, such as materials and gases, such as chlorine, spew forth.chlorine, spew forth.

As rivers, streams and glaciers move As rivers, streams and glaciers move over rock and soil, they dissolve over rock and soil, they dissolve salts, such as magnesium, sodium salts, such as magnesium, sodium and potassium, in them.and potassium, in them.

As waves pound the shoreline, they As waves pound the shoreline, they dissolve salts from the rocks.dissolve salts from the rocks.

Salinity LevelsSalinity Levels The salinity is lower in areas where freshwater The salinity is lower in areas where freshwater

rivers run into the ocean. Salinity levels are also rivers run into the ocean. Salinity levels are also affected by animals such as clams and oysters affected by animals such as clams and oysters that use calcium salts to build their shells. They that use calcium salts to build their shells. They remove salt from the water.remove salt from the water.

In warm ocean areas where there is little rainfall In warm ocean areas where there is little rainfall and much evaporation, the amount of dissolved and much evaporation, the amount of dissolved salts is much greater. In polar regions, the salts is much greater. In polar regions, the salinity levels are high because temperatures are salinity levels are high because temperatures are cold enough for ocean water to freeze. Pure water cold enough for ocean water to freeze. Pure water is removed and salts are left behind.is removed and salts are left behind.

Gases in Ocean WaterGases in Ocean Water

The most abundant gases in ocean The most abundant gases in ocean water are nitrogen, carbon dioxide water are nitrogen, carbon dioxide and oxygen.and oxygen.

The amounts of these elements vary The amounts of these elements vary with depth. They are more abundant with depth. They are more abundant at the ocean’s surface where sunlight at the ocean’s surface where sunlight causes more plant life.causes more plant life.

Temperature of Ocean WaterTemperature of Ocean Water

Warm water holds less dissolved gas Warm water holds less dissolved gas than cold water.than cold water.

When ocean water is cold, like in When ocean water is cold, like in polar regions, it sinks and carries polar regions, it sinks and carries oxygen rich water to the ocean oxygen rich water to the ocean depths.depths.

As a result, fish and other animals As a result, fish and other animals can live in deep parts of the ocean.can live in deep parts of the ocean.

Temperature of Ocean WaterTemperature of Ocean Water

Sun is the major Sun is the major source of heat for source of heat for the ocean.the ocean.

Motions of the Motions of the ocean, such as ocean, such as waves and waves and currents, mix the currents, mix the surface water and surface water and transfer the heat transfer the heat downward.downward.

The Ocean FloorThe Ocean Floor

The topography of the ocean floor is The topography of the ocean floor is different from the topography of the different from the topography of the continentscontinents

The Ocean FloorThe Ocean Floor

The ocean floor has higher mountains, The ocean floor has higher mountains, deeper canyons, and larger flatter plains. deeper canyons, and larger flatter plains. Earthquakes occur more often.Earthquakes occur more often.

The rocks are very different.The rocks are very different. The crust is thinner.The crust is thinner.

Edges of the ContinentsEdges of the Continents

The shoreline is a boundary between The shoreline is a boundary between where the land and the ocean meet.where the land and the ocean meet.

The area where the underwater edge The area where the underwater edge meets of a continent meets the ocean meets of a continent meets the ocean floor is called a continental margin.floor is called a continental margin.

Studying the Ocean FloorStudying the Ocean Floor

In 1872, the first expedition to explore the In 1872, the first expedition to explore the ocean began when the ocean began when the Challenger Challenger sailed sailed from England.from England.

Scientists used wire to measure the ocean Scientists used wire to measure the ocean depth.depth.

Scientists aboard used nets to collect Scientists aboard used nets to collect animals and plants from the ocean floor.animals and plants from the ocean floor.

Special thermometers measured the Special thermometers measured the temperature. Samples of water were temperature. Samples of water were collected.collected.

Present OceanographersPresent Oceanographers

Today oceanographers have modern Today oceanographers have modern instruments.instruments.

Underwater cameras provide Underwater cameras provide pictures of the ocean floor. Corers pictures of the ocean floor. Corers bring up samples of med and sand bring up samples of med and sand from the ocean bottom. from the ocean bottom.

Bathyspheres, bathscaphs and other Bathyspheres, bathscaphs and other submersibles are able to dive deep submersibles are able to dive deep under the surface to exploreunder the surface to explore

Mapping the Ocean FloorMapping the Ocean Floor

One of the most important goals is to One of the most important goals is to map the ocean floor. This is done by map the ocean floor. This is done by indirect methods such as echo indirect methods such as echo sounding, radar, sonar and sounding, radar, sonar and seismographic surveys.seismographic surveys.

Echo SoundingsEcho Soundings

All of these methods are based on the All of these methods are based on the same principles. Energy waves are sent same principles. Energy waves are sent down to the floor are reflected and return down to the floor are reflected and return to the surface, where they are recorded.to the surface, where they are recorded.

Knowing the speed of sound, 1500 m per Knowing the speed of sound, 1500 m per second, oceanographers can determine second, oceanographers can determine the depth.the depth.

The most complete picture was gathered The most complete picture was gathered from information from a satellite, the from information from a satellite, the SeasatSeasat, launched in 1978, launched in 1978

Assignment Assignment

Section 10.1 questions 1-6Section 10.1 questions 1-6