Physical OceanographyPhysical Oceanography

Chapter 20.1Chapter 20.1

Branches of OceanographyBranches of Oceanography

• Physical Oceanography - study of the Physical Oceanography - study of the motions of seawater, particularly waves motions of seawater, particularly waves currents and tidal motion. currents and tidal motion.

• Chemical Oceanography - chemistry of Chemical Oceanography - chemistry of seawater and reactions between the seawater and reactions between the atmosphere and hydrosphere. More atmosphere and hydrosphere. More recently looks at how changes in recently looks at how changes in seawater temperature (El Nino) and seawater temperature (El Nino) and salinity affect global climate. salinity affect global climate.

• Biological Oceanography - study of Biological Oceanography - study of life in the oceans, includes marine life in the oceans, includes marine biology and ecology. biology and ecology.

• Geological Oceanography - study of Geological Oceanography - study of the shape and geologic features of the shape and geologic features of the ocean floor.the ocean floor.

Major Major OceansOceans

• The three major oceans are : The three major oceans are : 1._______-largest, deepest, 1._______-largest, deepest, coldest, least salty. 2.__________- second coldest, least salty. 2.__________- second largest, shallow, warm, salty. largest, shallow, warm, salty. 3. _________- intermediate 3. _________- intermediate in depth, temperature, and salinity.in depth, temperature, and salinity.

• The _______Ocean near the north pole, and the The _______Ocean near the north pole, and the ____________ Ocean near the south pole contain ____________ Ocean near the south pole contain vast expanses of sea ice. vast expanses of sea ice.

PacificAtlantic

Indian

ArcticAntarctic

Methods of Studying the Ocean

The Topex/Poseidon _____________ orbits 1331 km above the Earth, gathering information about the oceans.

_____________ maps ocean floor topography by timing how long it takes sound waves to bounce off the ocean floor.

Underwater vessels called _________________ investigate the deepest ocean trenches.

satellite

Sonar

submersibles

Sonar (also called echo-Sonar (also called echo-sounding)sounding)

• Sound waves travel Sound waves travel how fast in seawater?how fast in seawater?

• How deep is the How deep is the water if it takes ten water if it takes ten seconds for the sound seconds for the sound wave to go from ship wave to go from ship to ocean floor and to ocean floor and back to ship?back to ship?

1,454 m/s

7,270 m

Calculation: (10 s times 1,454 m/s divided by 2 )

SubmersiblesSubmersibles

• Underwater research vessels, called Underwater research vessels, called submersiblessubmersibles, also enable , also enable oceanographers to study the ocean oceanographers to study the ocean depths.depths.

• They can perform tasks ranging from They can perform tasks ranging from photography to collecting samples.photography to collecting samples.

• Several types of submersibles have Several types of submersibles have been used for underwater research.been used for underwater research.

• One early type is the One early type is the bathyspherebathysphere, , a spherical diving vessel that was a spherical diving vessel that was first used for deep-ocean exploration.first used for deep-ocean exploration.

• This vessel carries scientists and is This vessel carries scientists and is lowered down by cables.lowered down by cables.

• Another type of submersible is called Another type of submersible is called a a bathyscaphbathyscaph..

• This is a self propelled, free moving This is a self propelled, free moving submarine.submarine.

• AlvinAlvin is a well known example. is a well known example.

• Hold 1 pilot and 2 scientists.Hold 1 pilot and 2 scientists.

AlvinAlvin

• Robot submersibles enable the ocean Robot submersibles enable the ocean to be study at depths that are unsafe to be study at depths that are unsafe for humans.for humans.

• Jason JrJason Jr, a highly maneuverable robot , a highly maneuverable robot toured the inside of the titanic.toured the inside of the titanic.

• They can tour undersea volcanoes They can tour undersea volcanoes and canyons.and canyons.

Jason Jr.Jason Jr.

• The picture below is of a _____________.The picture below is of a _____________.submersible