Umthombo 2 - Page 15



PHOTOGRAPHS: MARK CAWARDINE, SUPPLIED.
MAP: LANDSAT IMAGE MOSAIC OF ANTARCTICA TEAM, WIKI COMMONS
isotopes, for example, will allow us to tease apart and thus
better understand the different overlapping biological and
chemical processes in the area.”
Fawcett will also be working with marine biologist Dr
Tommy Bornman from Nelson Mandela University and
the South African Environmental Observation Network to
investigate the sea’s biological community and the rate of
photosynthesis and nutrient cycling by its phytoplankton
communities.
“We will be looking at questions like how the extended
daylight hours affect photosynthesis and how quickly CO2 is
being removed,” she says.
“The R/V SA Agulhas II is one of the most modern
research ships on the planet, equipped with a huge array of
cutting-edge scientific instruments,” says Fawcett. “While
the expedition is in the Weddell Sea, scientists will also
be flying drones over the ice as well as sending remotely
controlled robotic autonomous vehicles under it.”
Tracking climate change
The Weddell Sea is the site of the Larsen Ice Shelves. The
Larsen A and B ice shelves collapsed in 1995 and 2002,
respectively, and in July 2017, one of the biggest iceberg
calving events ever recorded took place when a piece of the
Larsen C Ice Shelf broke off from the mainland.
“In the past we have been able to view the ice from above
using satellite imaging and photographs taken from planes,”
explains Fawcett. “But this will be a chance for us to examine
the underside of the ice shelf, which is highly significant
because evidence shows that the Weddell Sea is warming
and these ice shelves are retreating at unprecedented rates.”
Ice shelves are influenced both by what occurs in the
water below them as well as the atmospheric conditions
above them, making them particularly important bellwethers
in understanding the rate of climate change.
“The thing about the ice shelves is that if they melt, they
don’t raise sea levels themselves because they are already
in the ocean. But if they go, then the ice behind them – on
the land – is more likely to start flowing towards the ocean,
displacing seawater as it enters the ocean, thus causing sea
levels to rise,” explains Fawcett.
“Hopefully the team will be able to visit the chasm that
has opened up between the ice shelf and the iceberg that
broke off in 2017,” says Ansorge. “To visit such a place, at
this time, and see what almost no-one else has seen is an
awe-inspiring thought.
u mth om bo
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