OCEAN
FORMATION
How did the oceans form??
Early Earth
Discussion:
• Earth is
approximately 4.6
Billion Years Old
• Earth is a closed
system with water
never leaving our
planet.
• So how did we get
water on Earth?
Formation of Oceans
Notes:
Early Earth was too hot for
oceans.
Consisted of molten rock.
As Earth cooled over time,
the surface solidified
(hardened).
Oceans formed 2 possible
ways:
– Comets
– Volcanism
Volcanism:
Notes:
Volcanic eruptions brought
magma and gases to the surface
through a process called
outgassing.
Gases:
• Water Vapor
• Sulfur Dioxide
• Carbon Dioxide
The water vapor condensed and
this was Earth’s first liquid water.
Comets and Asteroids:
Notes:
• More water vapor came
from asteroids and comets
that crashed into Earth
than volcanoes.
• Comets hit the Earth and
released water the water
filled the ocean basins over
geologic time.
MOTION
OF THE
OCEAN
TYPES:
Deep Water
Affected by:
- Density 
convection
currents
- Temp and
salinity
Temperature
When water cools, it contracts and the
water molecules move closer together.
This contraction makes he water denser
and sinks. When it expands, the
molecules move farther apart making it
less dense and rise to the top.
Salinity
When water freezes the salt in
the water does not freeze but
stays in the unfrozen water. The
dense polar water sinks and
begins the deep water currents.
ICE CUBE LAB
As the ice cube melts,
the cold melt water
from the ice cube sinks
to the bottom of the
cup forcing the water
from the bottom of the
cup to move toward
the surface which
transfers its heat to the
ice cube, causing it to
melt faster.
Freshwater Cup
ICE CUBE LAB
Meanwhile in the
saltwater, the cold
freshwater from the ice
cube floats on top of
the saltwater. Thus the
ice cube sits in a pool of
cold water, blocking
the heat from the
saltwater from getting
to the ice cube.
Salt Water Cup
ICE CUBE LAB
Why is this important:
- It demonstrates the
layers of the ocean.
- It demonstrates deep
water ocean
circulation with
convection currents
UPWELLING
Upwelling - deep ocean water rises
to the surface.
Strong winds blow surface water
away from shore that allows deeper
water to flow to the surface and take
its place.
An upwelling occurs when deep
ocean water rises to the surface.
When water comes up from the
deep, it brings a lot of nutrients with
it. That’s because nutrients settle to
the bottom over time. The nutrients
brought to the surface support many
living things.
TYPES:
Surface Water
Affected by:
- Air currents
- Waves
- Earth’s rotation
- Coriolis effect
- Location of the continents
- Tides
- Seismic Activity
- Tsunamis
Waves
Most ocean waves are
caused by winds.
A wave is the transfer of
energy through matter.
Ocean waves transfer
energy from wind
through water.
https://www.youtube.com/watch?v=7yPTa8qi
5X8
https://www.youtube.com/watch?v=DsSiMIYi
aUc
The energy of a wave
may travel for thousands
of miles.
However, the water itself
moves very little.
Tides
Tides are changes in the
rise and fall of sea level
caused by the
gravitational pull of the
Moon and Sun.
They occur all around
the globe.
High tides occur when
the water reaches its
highest level.
https://www.youtube.com/watch?v=DsSiMIYi
aUc
Low tides occur when
the water reaches its
lowest level.
Coriolis Effect
The Coriolis effect describes how
Earth’s rotation deflects winds and
surface ocean currents.
Coriolis causes freely moving objects
to appear to move to the right in the
Northern Hemisphere and to the left
in the Southern Hemisphere.
The objects themselves are actually
moving straight, but the Earth is
rotating beneath them, so they seem
to bend or curve.
http://video.mit.edu/watch/the-corioliseffect-4407/
https://www.youtube.com/watch?v=_sayCU1
TNyg