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Huge inverted canyons in Antarctica’s ice shelves may be a sign of dim future

We typically think that spacecraft can help studying foreign planets. However, we can also research our own planet from space and make some substantial discoveries. Scientists from The University of Edinburgh used a couple of satellites to see how the underside of Antarctica’s ice shelves is melting forming huge inverted canyons.

Ice shelves are changing due to climate. Understanding why and how exactly they are changing is important because they help stopping ice sheets from creeping into oceans. Scientists have noticed that there are huge inverted canyons forming on the underbelly of ice shelves and they wanted to research this phenomenon closer. These canyons, weirdly, cannot be seen so easily from the ground level, but can be analysed using satellites. This is important because these hollow sections are obviously making ice shelves weaker, pushing ice sheets to the ocean rising sea levels in the world.

Ice shelves like this are not as strong as they used to be – their collapse could result in a massive release of freshwater. Image credit: Ben Holt via Wikimedia

Scientists focused on Dotson ice shelf in West Antarctica. They used ESA’s CryoSat-2 to study changes in the surface of the ice sheet and the Copernicus Sentinel-1 mission to study how ice shelves flow. Researchers found that warm sea water flows under the ice shelf and then swirls around under the influence of Earth’s rotation. This phenomenon creates these large inverted canyons. Scientists say that this must have taken place for at least 25 year and possibly for longer. Furthermore, they discovered 200 metres deep and 15 km long channel, spanning the entire ice shelf.

This one canyon that scientists looked into releases about 4 billion tonnes of freshwater every year. Entire Dotson ice shelf releases 40 billion tonnes each year. Because these canyons are deepening, the flow of freshwater is likely to continue growing. This specific canyon is deepening at a rate of 7 metres per year. This will inevitably have a huge effect on local ecosystems and entire Earth. Dan Goldberg, one of the authors of the study, said: “This study reveals the complexity with which the ocean interacts with Antarctic ice shelves, and will be of value in assessing the future of the ice-ocean-biology system of the Antarctic coastline, and its sensitivity to changes in climate”.

Climate change is a very gradual process. However, once a breaking point is reached some extremities may happen. Just imagine the effect of a sudden release of billions of tonnes of fresh water. While it is not certain it is going to happen, scientists will have to continue monitoring these ice shelves.

 

Source: The University of Edinburgh

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