New data indicates warming and high-pressure seawater beneath the Thwaites Glacier in West Antarctica, called the ‘Doomsday glacier’, leading to vigorous melting. If other polar regions imitate the process, it could potentially lead to a reassessment of global sea-level rise projections.
A team of glaciologists led by researchers at the University of California, Irvine employed high-resolution satellite radar data to uncover evidence of the warm, high-pressure seawater intrusion beneath the glacier.
A statement by the scientists noted that the widespread contact between ocean water and the glacier—a process replicated throughout Antarctica and in Greenland—causes “vigorous melting” and may require a reassessment of global sea level rise projections.
‘Vigorous melting’ spotted by Finland’s ICEYE commercial satellite mission
In a bid to comprehend the impact of ocean-water interaction on glacial melting, glaciologists examined data collected between March 2023 and June 2023 sourced from Finland’s ICEYE commercial satellite mission.
These satellites represent a collection that resembles constellations in polar orbit around the planet. They employ InSAR – interferometric synthetic aperture radar – to continuously track changes on the Earth’s surface.
The data depicted the rise, fall, and bending of Thwaites Glacier. “These ICEYE data provided a long-time series of daily observations closely conforming to tidal cycles,” stated lead author Eric Rignot, UC Irvine professor of Earth system science.
“In the past, we had some sporadically available data, and with just those few observations it was hard to figure out what was happening,” he added.
“When we have a continuous time series and compare that with the tidal cycle, we see the seawater coming in at high tide and receding and sometimes going farther up underneath the glacier and getting trapped. Thanks to ICEYE, we’re beginning to witness this tidal dynamic for the first time.”
Thwaites Glacier most unstable in Antarctica
While Rignot noted that the project helped scientists better apprehend the behavior of seawater on the undersides of Thwaites Glacier.
He explained that seawater entering the base of the ice sheet, along with freshwater from geothermal heat and friction, accumulates and needs to flow. This water moves through natural channels or pools in cavities, creating pressure that lifts the ice sheet.
“There are places where the water is almost at the pressure of the overlying ice, so just a little more pressure is needed to push up the ice,” Rignot emphasized. “The water is then squeezed enough to jack up a column of more than half a mile of ice.”
Co-author Christine Dow, professor in the Faculty of Environment at the University of Waterloo in Ontario, Canada alluding to the glacier in question said that the Thwaites is the most unstable place in the Antarctic and contains the equivalent of 60 centimeters of sea level rise.
The challenge faced was underestimating the speed at which the glacier is changing as poses devastating consequences for coastal communities around the world.
The worry is that we are underestimating the speed at which the glacier is changing, which would be devastating for coastal communities around the world. “At the moment we don’t have enough information to say one way or the other how much time there is before the oceanwater intrusion is irreversible, says Dow.
“By improving the models and focusing our research on these critical glaciers, we will try to get these numbers at least pinned down for decades versus centuries. This work will help people adapt to changing ocean levels, along with focusing on reducing carbon emissions to prevent the worst-case scenario.”
The study was published in the journal Proceedings of the National Academy of Sciences.
