Looking to the past to predict the future | Polarjournal
The drilling camp of the SWAIS 2C project in West Antarctica. Photo: Craig Stevens, NIWA/New Zealand

A drill core from the sea floor under the Kamb Ice Shelf in West Antarctica is expected to provide information about past warm periods and thus enable more accurate predictions of future sea level rise. An international team of experts is currently on its way to the icy drilling camp.

“Sensitivity of the West Antarctic Ice Sheet to Two Degrees of Warming”, or “SWAIS 2C” for short, is the first project of its kind and not without risks: the large international team of more than 120 researchers and drilling experts will drill deeper through the West Antarctic Ice Shelf than ever before in order to take a sediment sample from the sea floor below. The team wants to use these geological climate records to better understand how quickly the ice sheet will melt and how much the sea level will rise.

Specifically, the project focuses on three aspects:

  • Did the West Antarctic Ice Sheet expand and retreat during the Holocene – a period of relatively stable climate that characterized the last 10,000 years before the Industrial Revolution and the beginning of the Anthropocene?
  • How do marine ice sheets react to a world that is 1.5° – 2°C and more than 2°C warmer than in pre-industrial times?
  • What are the local, regional and global effects and consequences of the Antarctic ice sheet’s response to this warming?
In order to obtain the climate records in the marine sediment, the team must first drill through the ice shelf with a hot water drill. Graphic: GNS Science

“In the Paris Agreement, we committed to keeping global average temperatures well below 2°C compared to pre-industrial conditions. Models tell us that the West Antarctic Ice Sheet will collapse once this value is exceeded. So far, however, this cannot be confirmed – simply because we do not yet have sound geological evidence that would allow us to define the behavior of the ice sheet during past warm periods,” Johann P. Klages said, marine geologist at the Alfred Wegener Institute, German co-coordinator and member of the SWAIS 2C science team.

The plan is to drill up to 200 meters deep into the seabed. But before the sediment sample can be obtained, the team has to overcome the almost 600-meter-thick Kamb ice shelf and around 50 meters of ocean water below it. According to Andreas Läufer, geologist at the Federal Institute for Geosciences and Natural Resources and German coordinator and member of the SWAIS 2C science team, they will use a custom-built drilling rig to drill a 35-centimeter diameter hole in the ice.

“There, we will then position a special sediment coring system over the hole, lower a hollow drilling system to the seafloor, and drill to depth for hopefully obtaining long sediment records from West Antarctica’s past,” says Darcy Mandeno from the Antarctic Research Centre in Wellington, New Zealand, leader of the drilling work for SWAIS 2C, in a press release from the Alfred Wegener Institute.

This season, the drilling site is located on the Kamb Ice Shelf (KIS) on the western edge of the Ross Ice Shelf. A further borehole is to be drilled at the Crary ice margin (CIR) next year. Map: Marlo Garnsworthy, SWAIS 2C

This type of research is of great importance so that we as a global society have a chance to adapt to rising sea levels. The entire West Antarctic Ice Sheet contains so much ice that it would raise the sea level by up to five meters if it melted completely. How much and how quickly the ice in West Antarctica will melt cannot be predicted with any certainty at the moment. It is only known that some regions, such as Thwaites Glacier, are melting particularly quickly. However, it remains unclear when and under what climatic conditions the ice shelves, which still act as a brake on the inland ice, will collapse. It is therefore crucial to look for answers that have been deposited in the sediments of past, warmer times.

Experts from Germany, New Zealand, the USA, Australia, Italy, Japan, Spain, Korea, the Netherlands and the United Kingdom are working on the project. The approximately 35 international research institutions include the Alfred Wegener Institute, the British Natural Environment Research Council, the Federal Institute for Geosciences and Natural Resources, the Korea Polar Research Institute and others.

The field work will begin shortly on the Kamb Ice Shelf and will continue until January 2024. Work on the Crary ice margin will begin in the following field season from November 2024.

Julia Hager, PolarJournal

Link to the project: https://www.swais2c.aq

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