Maia McGuire, PhD University 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.

Activity Where’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 earth/Water/circulation1.html

Activity Show the relationship between temperature and density of water (complex concept, but simple demonstration!) ( What will happen as the ice melts? Why? Warm water Ice (colored)

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

What makes water move? Water moves because of currents Temperature can make water move The earth’s rotation makes water move “Coriolis effect” results in clockwise circulation in northern hemisphere and counterclockwise in the southern hemisphere

Zooming in on Florida Gulf has wide continental shelf Loop Current Atlantic has narrow shelf Gulf Stream Longshore currents

Continental shelf….?

Back to the ocean…. We generally cannot see currents sometimes we can see the boundary along the edge of a current (“weed line”)

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 Jacksonville Two 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 2 nd : 4.6 to 5.2 (new moon) February 11 th : 3.2 to 3.3 February 18 th : 6.2 to 6.4 (full moon)

Waves Most commonly caused by wind blowing on the ocean’s surface.

Activity Wind and waves (Monterey Bay Aquarium) Waves in a bottle

A very little ocean chemistry The sea is salty Where 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 water It is heavier Things float better in salt water We cannot tell fresh water from salt water by looking at it

Activity Where Rivers Meet the Sea (For Sea) Fresh water Salt water

Activity The weight of water (Sea World)