Antarctica may seem like a static environment: the white and still landscape is frozen in stillness, but more than we can imagine under snow.
More than a decade ago, scientists made such a discovery when they analyzed data from NASA’s ISISAT satellite and found that differences in the height of the ice in western Antarctica reflect massive subglacial movements beneath the ice sheet.
Prior to its discovery, the melted lakes – hidden deep beneath the ice sheet, where the ice meets the continental bedrock – were thought to exist in isolation.
(Siegfried et al. / NASA Goddard / YouTube)
In 2007, researchers discovered that fluctuations in the height of ice on the Antarctic surface are an indication of the flow of water between the hidden network of subglacial lakes, which alternate before flowing into the South Ocean.
Revealing two previously undiscovered lakes, the ICSAT-2 mission, launched in 2018, provides scientists with more information about this niggling and deeply dug network.
As Matthew Siegfried, a glaciologist at the Colorado College of Mines, says: “ICESat-2 is the equivalent of wearing your glasses after using ICESat. The data is very high resolution, and we can map the lake’s boundaries to the surface.”
In a new study, Siegfried and his co-researchers combined ultimatum data from the ICESAT-2 and the original ICISAT mission with measurements from the European Space Agency’s (ESA) ice observation satellite Cryosat-2.
By integrating data sets – from 2003 to 2020 – researchers will be able to observe active subglacial lakes on time scales shorter than the ICESat-2 recurrence cycle (with an interval of 91 days for you to re-observe the same area).
The researchers wrote: ‘Surface deformation caused by the filling and removal of active subglacial lakes provides one of the few remotely accessible windows for the evolution of basic water systems; Otherwise, these systems are hidden for up to 4 km. [2.5 ميل] Ice. “
In addition to giving us a more detailed view of the work and design of known subglacial lakes in Antarctica – more than 130 of these documents have already been documented – the analysis found two anomalies that appear to be hidden lakes, which have not been found before.
These lakes, also known as the Lower Subglacial Lake Conway (LSLC) and Lower Mercer Lake (LSLM), are located near previously discovered lakes.
A few weeks ago, one of the researchers involved – Helen Fricker, a glaciologist at the Scripps Institution of Oceanography – wrote a detailed study of a dramatic lake erosion event in East Antarctica, where a shallow lake disappeared on a floating ice shelf.
Under the western Antarctic ice sheet, water from subglacial lakes is thought to gradually flow into the ocean, making it difficult to even imagine a hidden escape route.
Results reported Messages Geophysical research.
Source: Science Alert