Antarctica appears like a primarily static environment – a mostly quiet landscape frozen into place.
However, there is a lot more happening under the ice than we are aware of.
Over ten years ago, scientists found out the news when an analysis of NASA‘s ICESat satellite data showed that the changes in ice elevation in West Antarctica reflected a considerable mass of subglacial water movement beneath the ice sheet.
Before the discovery, it used to be thought that hidden meltwater lakes were solitary, completed separated from one another.
However, in 2007, researchers discovered that variations in the height of Antarctica’s surface ice translated into the movement of water flowing between a hidden array of subglacial lakes, which alternately fill and drain before their water makes its way all the way into the Southern Ocean.
The ICESat follow-up mission, dubbed ICESat-2, was launched three years ago. It provides scientists with a more comprehensive glimpse into the mysterious, deeply buried lake network while also uncovering two lakes never before observed.
Matthew Seigried, a glaciologist from the Colorado School of Mines, said:
“The discovery of these interconnected systems of lakes at the ice-bed interface that are moving water around, with all these impacts on glaciology, microbiology, and oceanography – that was a big discovery from the ICESat mission. ICESat-2 is like putting on your glasses after using ICESat, the data are such high precision that we can really start to map out the lake boundaries on the surface.”
In a recent study, Siegfried and his fellow researchers put together altimetry data from ICESat-2 and the initial ICESat mission, combined with data from CryoSat-2, an ice-tracking satellite operated by the European Space Agency (ESA).
By merging the datasets, corresponding to the period from 2003 to 2020 – the scientists can track active subglacial lakes at timescales more precise than what ICESat 2’s repeat cycle (a 91-day gap before it could observe the same region again) offered.