Intro to the Ocean

Maia McGuire, PhDUniversity of Florida Sea Grant Extension

Program

Only one ocean…There is one ocean with many ocean basins,

such as the North Pacific, South Pacific, North Atlantic, South Atlantic, Indian and Arctic.

The ocean is the dominant physical feature on our planet Earth — covering approximately 70% of the planet’s surface.

ActivityWhere’s the ocean?

Ocean sciences

Kindergarten and first grade will be studying ocean LIFE, however it is important to understand some of the physical and chemical aspects of the ocean as these affect the biology…

Ocean circulation

http://www.windows2universe.org/earth/Water/circulation1.html

http://msx4.pha.jhu.edu/ssip/asat_int/ocean.html

ActivityShow the relationship between temperature

and density of water (complex concept, but simple demonstration!) (www.angelfire.com/la/kinderthemes/oscience.html)

What will happen as the ice melts? Why?

Warm water

Ice (colored)

Focus on the North AtlanticClockwise circulation (surface currents)Gyre (Sargasso Sea) in the center

What makes water move?

Water moves because of currentsTemperature can make water moveThe earth’s rotation makes water move

“Coriolis effect” results in clockwise circulation in northern hemisphere and counterclockwise in the southern hemisphere

Zooming in on FloridaGulf has

wide continental shelf

Loop Current

Atlantic has narrow shelf

Gulf StreamLongshore

currents

Continental shelf….?

http://www.unfalumni.org/?p=139

Back to the ocean….We generally cannot see currents sometimes

we can see the boundary along the edge of a current (“weed line”)

http://www.safmc.net/Library/Sargassum/tabid/414/Default.aspx

What about tides?Tides are the result of gravitational pull of

the moon and sun, in combination with the rotation of the earth.

Source: Hayes & Michel, 2008

Tides in JacksonvilleTwo high and two low tides each day; about 6

hours apart (alternating high and low). Actual time of low tide varies along the coastline. Data are for Mayport. Difference between high and low

tide (feet):

February 2nd: 4.6 to 5.2(new moon)

February 11th: 3.2 to 3.3

February 18th: 6.2 to 6.4(full moon)

WavesMost commonly caused by wind blowing on

the ocean’s surface.

ActivityWind and waves (Monterey Bay Aquarium)Waves in a bottle

A very little ocean chemistryThe sea is saltyWhere do the salts come from?The salinity of the Atlantic Ocean is about 36

parts per thousand (ppt or ‰) or 3.6 %. These salts contain minerals which are often

used by marine plants and animals to make skeletons, etc.

Most marine animals need oxygen, just like land animals, however they breathe oxygen that is dissolved in the sea water (they cannot breathe in air).

Salt water is different from fresh waterIt is heavierThings float better in salt waterWe cannot tell fresh water from salt water by

looking at it

ActivityWhere Rivers Meet the Sea (For Sea)

Fresh water

Salt water

ActivityThe weight of water (Sea World)