We’ve heard about the rubber duckies,
but what else is out there?
• In late May of 1990, a large
wave washed 21 shipping
containers overboard on the
vessel Hansa Carrier
containing 80,000 Nike shoes
ranging from children’s shoes
to large hiking boots.
• About a year later, must of the
footwear was ashore and was
wearable after washing.
• Unfortunately the shoes were
not tied to one another !
• Other shipments have
accidentally been
spilled into our oceans.
Oceanographic
information suggests
many Legos will reach
the United States soon.
They include 48,500
black Lego witch hats….
• 26,600 yellow
Lego life
preservers
• 18,200 tiny
black Lego
frying pans
• 500,000 cans of
beer lost from a
Chinese cargo
ship near Hong
Kong
• And hundreds
of thousands
of flip-flop
beach sandals
on Australia's
Cocos and
Keeling Islands.
What are surface currents?
• Surface currents are ocean
currents that occur at or near the
surfaces of the ocean. They are
caused by wind.
What are the 3 factors that affect
surface currents?
• Continental Deflections – When surface
currents meet continents, the currents are
deflected and change direction.
• Coriolis Effect—The deflection of moving
objects from a straight path due to Earth’s
rotation.
• Global Winds– Winds that blow across the
surface of Earth’s oceans push water across
Earth’s surface.
How does the sun power surface
currents?
• The sun heats air near the
equator more than it heats air at
other latitudes. Pressure
differences in the atmosphere
cause wind to form, and winds
cause surface currents to form.
How do deep water currents form?
• Deep currents are caused by differences in
water density. Ocean water density is affected
by how much salt is in the water (salinity).
When ocean water at the surface becomes
denser than water below it, the denser water
sinks. The water moves from the surface to
the deep ocean, forming deep currents.
How do ocean currents transport
energy?
• Near the equator, the ocean absorbs a large
amount of solar energy. Ocean currents carry
this energy from the equator toward the
poles. When the warm water travels to cooler
areas, the energy is released back into the
atmosphere.
How do ocean currents transport
matter?
• Ocean currents transport
water, matter such as solids,
dissolved solids, and gasses.