Sunday 1 April, 2007 -
Wilkins Runway is on schedule to accommodate
regular flights, and the progress of several
major science projects signal a successful
season in Antarctica for Australia.
Director of the Australian Antarctic Division
Dr Tony Press said that research this summer
will provide critical information towards
understanding a range of global issues such
as climate change, the effects on ecosystems
of increased carbon dioxide uptake by the
Southern Ocean, estimating sustainable krill
fishery quotas and remediation of terrestrial
and marine environments contaminated by
oil spills in previous times.
A busy work programme at Wilkins Runway
near Casey station ensures that Australia's
Antarctic Airlink is on schedule to begin
regular flights next season.
The Australian Government recently announced
that an Airbus A319 will be used on the
route between Hobart and Antarctica to carry
scientists, support personnel and some equipment
south in just under five hours, compared
with more than a week by ship.
"While shipping will still be used
to supply stations and carry heavy equipment,
helicopters and some expeditioners we are
looking to transport most scientists by
air. The time saved by flying will greatly
benefit scientists," Dr Press said.
Amery Ice Shelf 'loose tooth'
Scientists have installed a number of broadband
seismometers and 'creep meters' at the site
of the 'loose tooth' on the Amery Ice Shelf
– the largest in East Antarctica - between
the Davis and Mawson stations. The creep
meter, to stay over winter, will directly
measure the amount of opening of an active
rift near its tip. This information will
be used back in Australia and the United
States by scientists working on this collaborative
project which brings together experts from
the Antarctic Climate and Ecosystems Cooperative
Research Centre, University of Tasmania
and the Scripps Institution of Oceanography
in California.
The so-called 'loose tooth' covers an area
of around 900 square kms of the Amery Ice
Shelf and has been an area of interest to
Australia since the first rifts started
to develop in 1995. Since then the two rift
systems have been moving at a rate of around
four to eight metres a day and opening episodically
by some cm every 10-30 days.
Heading the project, Professor Richard
Coleman of the University of Tasmania, said
that this research will provide a clearer
idea on the mechanics of ice shelf rifting.
"To predict what is going to happen
to the Antarctic ice shelves in a warming
climate, it is critical to incorporate the
calving process in a correct manner. Currently,
calving is very crudely included in the
models, therefore we cannot make accurate
predictions," Professor Coleman said.
Close monitoring of the Amery rift system
began in the 2002/03 summer to get a clearer
idea of why the rifting occurs and what
causes ice shelves to break off to form
of icebergs. The last major iceberg calving
of Amery was in 1962/63. The next event
may occur in around five to seven years,
although there is no accurate way of knowing
how large that calving might be.
Southern Ocean marine science
The Sub-Antarctic Zone Sensitivity to Environmental
Change voyage spent five weeks in the Southern
Ocean studying the effects of increasing
carbon dioxide on planktonic organisms –
the microscopic plants and animals in the
ocean - and the ability of the ocean to
continue to process carbon. The Southern
Ocean is a perfect setting to study the
effects of ocean acidification as carbon
dioxide is more readily absorbed by colder
waters than warmer waters.
The project, coordinated through the Australian
Antarctic Division, Antarctic CRC and CSIRO,
brought together 60 scientists from seven
countries to examine planktonic organisms
such as certain algae and snail-like pteropods
for the effects of acidification which can
hinder the development of shells in some
species.
The findings from this research will provide
critical information on the processes that
govern the ocean's natural uptake of carbon
dioxide, the ocean's ability to continue
to process carbon dioxide, and the likely
impacts of acidification on the organisms
that form the base of the food web in the
Southern Ocean.
Krill distribution research aids in sustainable
fisheries
The long-running Adelie penguin monitoring
programme at Bechervaise near Mawson station
is providing useful information on krill
abundance. Adelies are large consumers of
krill and useful indicators of the effects
of changes in krill abundance brought about
by harvesting.
In 1991, the Commission for the Conservation
of Antarctic Marine Living Resources (CCAMLR)
established an international programme to
monitor the impact of the krill fishery
on the Southern Ocean ecosystem and assist
sustainable management.
Australia then set up the Bechervaise Island
Adelie monitoring programme to study the
effects of krill abundance on these important
predators. An automated system was installed
to measure the time the penguins spend at
sea foraging for krill, their weight change
throughout the breeding season, and the
amount of food brought back for their chicks.
The successful system continues today.
To further assist in the collection of
data, the Australian Antarctic Division
recently developed an automated camera,
powered by solar panels, to monitor aspects
of Adelie chick survival and breeding chronology.
During the winter months the cameras 'sleep'
then 'awaken' as the summer returns to record
a series of photographs throughout the breeding
season.
This season, six cameras were installed
at new island sites in the Mawson region.
This will give us access to information
over a much broader area than Bechervaise
alone. This will provide a more comprehensive
picture of the needs of penguins in this
study.
One major aim of CCAMLR is to ensure that
the human harvest of krill does not adversely
affect any element of the Southern Ocean
Antarctic marine ecosystem. Further details
will be available as the data are analysed.
