Umthombo 2 - Page 14



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The Weddell Sea is one of the most remote and
least-studied places on Earth.
Autonomous underwater vehicles will survey the
sea floor, study cavities on the underside of the
ice shelf and search for the wreck of Endurance.
The Weddell seal, found in Antarctica, is the
most southerly breeding of all mammals.
The Weddell Sea is a deep embayment of the
Antarctic coastline.
OPPOSITE The South African polar research and
supply vessel, R/V SA Agulhas II, will be used for
the 2019 Weddell Sea Expedition.
A window into time
According to Ansorge, the Weddell Sea is of importance to
oceanographers because many of the waters and nutrients
that control the structure and functioning of ocean
systems originate in the area.
“Due to differing water densities the ocean is
divided into layers,” she explains. “There is the
bottom water, the deep water, the intermediate
and the surface water. Just off Antarctica there is
a water mass called the Antarctic bottom water,
which forms along the shelf region in the Weddell
Sea, and simply put, creates a waterfall effect
down the side of the continental shelf due to its
high density. This water mass then travels to all
of the sea basins, so whatever happens there
really influences the rest of the ocean.”
Fawcett explains that this influence includes the
transport of heat and gases, as well as nutrients, like
phosphorus and nitrogen, which all ocean life require.
Fawcett and Hutchinson will be measuring all the
physical characteristics of the area, from the salinity of
the water to the temperature and carbon dioxide (CO2)
concentrations. “While we are there, I will also be looking at
the isotopes that are present,” says Fawcett. “The nitrogen
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