The Weddell Sea off Antarctica, one of the coldest, harshest and most remote locations in the world, will be explored next year by a major international scientific expedition in which South African research organisations and scientists will play vital role.
The January/February expedition will survey the underside of the Larsen C Ice Shelf, document the rich and little-studied marine life of the western Weddell Sea ecosystem and attempt to locate the wreck of Sir Ernest Shackleton’s ship Endurance, which was trapped, crushed by the ice and sunk there in 1915.
The 45-day voyage will be conducted from the South African polar research and logistics vessel the SA Agulhas II, owned by the Department of Environmental Affairs and managed by South African company Amsol.
Built in 2012, the vessel is one of the largest and most modern research ships anywhere in the world, has a wide range of science laboratories and facilities, and offers a powerful and effective platform for the multidisciplinary research.
The vessel has been chartered by a charitable trust in the Netherlands, The Flotilla Foundation, which will use the ship for a pioneering programme of science and exploration planned by University of Cambridge’s Scott Polar Research Institute director Professor Julian Dowdeswell.
Ocean researchers from the University of Cape Town (UCT), Nelson Mandela University (NMU) and the South African Environmental Observation Network will join an international team of scientists from institutions around the world, including the UK-based Nekton Foundation and New Zealand-based University of Canterbury.
The team will comprise glaciologists, marine geologists, marine biologists, marine biogeochemists, oceanographers and marine archaeologists, who will use autonomous underwater vehicles (AUVs) to survey the sea floor down to beyond 3 000 m, study cavities on the underside of the ice shelf, and search for the wreck of Endurance.
Antarctica has about 1.5-million square kilometres of floating ice shelves, which have been surveyed and studied from above, but only rarely from beneath.
Many of these ice shelves are thinning and retreating rapidly, making scientific investigations here timely. The Larsen A and B ice shelves collapsed suddenly in a matter of weeks in 1995 and 2002, respectively, and one of the biggest iceberg calving events ever recorded took place from Larsen C Ice Shelf in July 2017.
Ice shelves are of particular scientific interest because they are susceptible both to atmospheric warming from above and ocean warming from below.
The Weddell Sea has been nominated as a large, international Marine Protected Area, with the support of the South African government, and the expedition will gather vital baseline data on the rare and little-studied species, which inhabit this ecosystem, as well as studying the key physical processes driving changes in the region’s sea ice, ocean currents and the fringing ice shelves.
Coordinating with the underwater research and survey work, Professor Wolfgang Rack and his team from Gateway Antarctica at the University of Canterbury, will use specially-equipped aerial drones to measure sea ice thickness and snow depth, and will also assist with the navigation of the SA Agulhas II through the pack ice in the Weddell Sea.
The drone measurements will be coordinated with data from an upward-looking AUV to give a better understanding of sea ice formation.
University of Cape Town Professor Isabelle Ansorge said on Tuesday that participating in the Weddell Sea Expedition 2019 would give South African researchers “an unprecedented opportunity to investigate and explore one of the most remote, and least-studied places on our planet, and to collaborate with international research colleagues across different disciplines”.
“Ice shelves surrounding the Weddell Sea are important because they affect the mass-balance and stability of the Antarctic ice sheet, as well as ocean-current circulation. If ice shelves thin, break up to produce icebergs and retreat as the atmosphere and ocean waters warm, then ice flow from the interior accelerates and more mass is lost, contributing to global sealevel rise,” Dowdeswell commented.
He further added that the melting at the base of ice shelves and calved icebergs also released fresh water, which could inhibit the generation of very dense Antarctic bottom water; one of the major drivers of the thermohaline circulation of the oceans, which provided vital nutrients to major fishery grounds around the world.
The Weddell Sea Expedition 2019 hopes to inspire young people around science, engineering and technology, and the protection of Antarctica, and is partnering with the Royal Geographical Society to ensure that the expedition’s research and findings are disseminated as widely as possible to schools and students in the UK, South Africa and beyond.
The programme will also work with the existing schools outreach programmes developed in South Africa by UCT and NMU to expand student knowledge of polar science and environmental issues in the Weddell Sea.