2. A River Runs Through It!!
� Ever go walking in a lake – or in the ocean – a feel a
stream of cool moving water pass around your or over
your foot?
� If so, you have felt a current!!
� A current is just that – a river of water that moves
through a larger body of water. In this case, we are
talking about currents in the ocean!
3. What forms a current?
� Well, lots of things!!
� Gravitational pull of the moon!
� Temperature changes!
� Differences in salinity!
� Water depth!
� Shape of the shoreline!
� Waves!
� Wind!
� Lots of things can get a current moving!
5. But what do currents do?
� Fast moving currents help boats cross the ocean quicker!
� Back in the old days, sailing ships would, basically, hitch a ride
on ocean currents and use them to finish their voyages quicker.
� Animals often use currents to travel. For example, the larvae of
the European Eel actually travels on the Gulf Stream – a really
big warm water current – to Europe where it will mature and
grow. Without that current, it could not travel.
� Currents can also do this:
� Take warm water from warm climates to cold climates.
� Take cold water from cold climates to warm climates.
� Both of these can change the weather patterns of the climates
getting the water.
6. The Gulf Stream
� The Gulf Stream is a powerful warm water ocean current
that begins near the tip of Florida, cruises up the eastern
coast of the USA, and then heads across the Atlantic Ocean
to Europe.
� The Gulf Stream is a BIG ribbon of water. It is usually about
62 miles wide, and from about 2,600 to 3,900 feet deep.
� It is fastest nearest the surface, with water moving at about
6 miles per hour.
7. Gimme a Big Gulf (stream)!!
� The Gulf Stream, because it is a warm water current,
influences the climates of many places.
� Florida can thank the Gulf Stream for keeping 77 degree
Fahrenheit water off its coast during the winter.
� Northern Europe can thank the Gulf Stream for bringing warm
water to its harbors to keep ice from forming so ships can
dock.
� The western parts of England and Ireland are actually a couple
degrees warmer than the eastern sides because of the warm
water brought by the Gulf Stream.
9. Some cool Gulf Stream
Tidbits!
� Juan Ponce de Leon first documented the Gulf Stream
in 1513! Spanish explorers used it to make their trips
across the Atlantic Ocean easier!
� The Gulf Stream brought many of the first settlers to
North America to the east coast. St. Augustine, a
Spanish settlement and the oldest city in the United
States, sits on the eastern coast of Florida very near the
large current.
10. Now hold on . . .
� Is it only currents that cause the water in the oceans to
move around?
� Uhhh . . . . NOPE!!!
� Tides and waves also cause water to move!!!
11. When the moon hits your eye . . . .
� Tides are caused by the moon!!!
� Remember that thing called GRAVITY?!?! Well, we
know the Earth exerts a gravitational pull on the
moon. The opposite is also true – the moon pulls on
the Earth!!!
� The moon is actually trying to pull the Earth closer to
it!! Because the Earth is bigger, that won’t happen, but
that gravitational pull from the moon CAN move the
water on Earth around!!
12. How it works!!!
� The gravitational pull of the moon causes the water to
bulge outward towards the moon. This produces a high
tide. There is another bulge on the opposite side of the
Earth, which also produces a high tide.
� Because the two sides of the Earth are bulging outward and
producing a high tide, the rest of the water is being pulled
inward and is experiencing a low tide.
� This happens twice a day – usually around 12 hours a part.
� Tides differ each day, because the moon is not always in
the same place in relationship to the moon – and will also
differ during different season AND during the lunar cycle
each month!!!
14. Catch a wave!!!
� Water also moves by waves!!!
� Waves are caused by a variety of forces!
� Most waves you will see are caused by wind blowing
across the surface of the water!
� Waves can also be caused by the movement of the tides!
� Large, dangerous waves – tsunamis – can be caused by
violent earthquakes on the ocean floor!!!
