thejournal.ie with Christine Dow 17 June 2018
Climate change could be accelerating a rise in sea levels to a greater extent than previously thought, researchers have found.
A new study by an international team of polar scientists has discovered that the process of warmer ocean water destabilising ice shelves from below is also cracking them apart from above, increasing the chance they’ll break off.
“We are learning that ice shelves are more vulnerable to rising ocean and air temperatures than we thought,” Christine Dow from the University of Waterloo in Canada, who led the research, said.
“There are dual processes going on here. One that is destabilising from below, and another from above.
“This information could have an impact on our projected timelines for ice shelf collapse and resulting sea level rise due to climate change.”
Over the course of two years, researchers used radar surveys and Landsat imagery (from Earth-observing satellites co-managed by the US Geological Survey and Nasa) to monitor ice shelves in locations such as Antarctica and Greenland.
They found that as warmer salt water erodes channels into the ice that attaches glaciers to stable land, it also generates massive vertical fractures splitting glaciers from above and below. Surface water melting on top of the ice shelves then pours into these cracks, accelerating the problem further.
“This study is more evidence that the warming effects of climate change are impacting our planet in ways that are often more dangerous than we perhaps had thought,” Dow said.
“There are many more vulnerable ice shelves in the Antarctic that, if they break up, will accelerate the processes of sea level rise,” she added.
The study was recently published in Science Advances.