THE OCEAN GREAT CONVEYOR BELT
Nindya Aristia Pratiwi - 15514013
The ocean is not a still body of water, it is in constant motion. It can be proved by our
experience when we swim in the ocean we feel an ocean current pulling us along or when we
watch waves crash onto shore. The ocean has surface current and also deep underwater
current. Surface currents are caused by the Earth’s various wind patterns. The example of
surface current is Gulf Stream that move water across the globe like mighty rivers. Deep
underwater current in the ocean is more massive but more slowly than surface current. The
underwater currents will mix the ocean’s water on a global scale. A process of ocean’s water
mixing is known as thermohaline circulation or the ocean conveyor belt.
The ocean conveyor belt is the circulation of waters throughout the world's oceans. It
is also called as thermohaline circulation because this circulation is driven by differences of
temperature and salinity (saltiness). The temperature and saltiness of the ocean’s water will
affect the density of ocean’s water. In the seas near Greenland and Norway, the water is cold.
This water is known as the North Atlantic Deep Water, and it is one of the primary driving
forces of the conveyor belt. The force of the sinking cold water pushes the existing North
Atlantic Deep Water south, toward Antarctica, in a slow-moving underwater current. When it
reaches Antarctica, the water flows east with the Antarctic Circumpolar Current, a massive
and powerful current that circles the continent. Parts of the Antarctic Circumpolar Current
flow northward and move into the Indian and Pacific Oceans. As the deep, cold water travels
through the oceans, it mixes with warmer water. In the Pacific, the surface water flows
through the Indonesian islands into the Indian Ocean, around southern Africa, and back into
the Atlantic. The warm waters eventually travel back to the North Atlantic Deep Water,
completing the global loop.
The temperature of warm water that enters the northern Atlantic Ocean will be
decrease because it adjusts with the arctic’s temperature. And the sea iceberg is formed by the
water but the salt does not freeze and left behind in the surrounding. It makes the salinity in
the northern Atlantic ocean is increase. Due to the added salts and the reduction in ocean’s
water temperature, the ocean’s water is now denser. The denser ocean’s water will sinks
toward the ocean bottom. The surface water will be replacing the sinking water and it creates
the current. After that the cold water will be move to south, past the equator, and travels
around the edge of Antarctica. The cold water is getting “recharged” in Antarctica because
Tugas Pengetauan Fisik Laut 1 – Nindya Aristia Pratiwi
the temperature in Antarctica is still low and make the cold water is not getting hotter. Then
the cold water move into the Indian Ocean and Pacific Ocean. When it past the equator, the
ocean’s water will get warmer because of the temperature in equator is higher than in
Antarctica. The evaporation in equator is high but the precipitation is high also so it will
make the salinity of ocean’s water decrease. The temperature is warmer and the salinity is
low, so it will make the ocean’s water become less dense and they will rise to the surface.
When the water is upwelling, the phytoplankton and other nutrient in the sea floor will also
rising to the surface. After that, they will return to the northern Atlantic Ocean where the
cycle begins.
This conveyor belt is important for sea nutrient cycle and also carbon dioxide cycle.
Cold waters are enriched with nutrient and carbon dioxide when they travel in the bottom
layer because the bottom layer contains many nutrients like phytoplankton that have died and
sinks to the bottom. The food chain itself is depends on cool-nutrient rich cool waters that
support the growth of algae or any nutrients. Then that cool waters will get warmer and
upwelling in equator and provide the nutrient needs in the surface of the ocean because there
are many living things that need nutrients in the surface.
The great ocean conveyor belt may be affected by climate change. Earth’s
temperature is increase from time to time and it makes the iceberg is easier to melt. So, when
the iceberg is easier to melt the salinity of northern Atlantic Ocean will not decrease and it
makes the conveyor belt is not working properly. When the great ocean conveyor belt is not
working properly, it will affect potentially drastic temperature changes in Europe.
So, the great ocean conveyor belt has impact to temperature changes in Europe but
also the great ocean conveyor belt is being affected by climate change in this earth. The great
ocean conveyor belt is important to marine food chain and carbon dioxide cycle. The water in
ocean conveyor belt will move from the northern Atlantic Ocean to southern Atlantic Ocean
then split into two ways, to Indian Ocean and to Pacific Ocean then it turn back and going
back to the northern Atlantic Ocean and it completing the global loop. It takes almost 500
until 1000 years to completing the global loop because the current is slow-moving. We need
to protect our earth from global warming so the great ocean conveyor belt will always
working properly and there are no drastic temperature changes in many regions.
Tugas Pengetauan Fisik Laut 1 – Nindya Aristia Pratiwi
References
o http://education.nationalgeographic.org/encyclopedia/ocean-conveyor-belt/
o http://oceanservice.noaa.gov/education/kits/currents/06conveyor.html
o http://pmm.nasa.gov/education/videos/thermohaline-circulation-great-oceanconveyor-belt
o http://www.encyclopedia.com/article-1G2-3079000129/great-conveyorbelt.html
Tugas Pengetauan Fisik Laut 1 – Nindya Aristia Pratiwi