Guwahati: In a potentially game-changing discovery, scientists have discovered massive amounts of water hidden in the sediments beneath an Antarctic ice stream which could help us better grasp how it might affect global sea levels. The latest discovery backs up what scientists had suspected.
Researchers projected that squeezing out this water on the surface would result in a lake ranging in depth from 220 to 820 metres. This amount of water would be enough to submerge the 182-meter-high Statue of Unity.
The crew was only able to photograph one of these ice streams on the frozen planet but there are likely to be many more that can offer light on how the system functions and changes over time in response to climate change. The measurements of the Whillans Ice Stream were taken by them.
This groundwater which extends for more than a kilometre and contains more than 10 times the fluid volume of the shallow hydrologic system above was discovered and published in the journal Science. The study was led by researchers from Scripps Oceanography and Columbia University’s Lamont-Doherty Earth Observatory.
“Ice streams are significant because they funnel nearly 90% of Antarctica’s ice from the interior out to the margins,” said Chloe Gustafson, a postdoctoral researcher at Scripps Institution of Oceanography adding that more Antarctic ice streams are likely to have groundwater beneath them.
Scientists have long speculated on the existence of vast reserves of groundwater beneath the Antarctic ice sheets and their potential contribution to the planet’s functioning. They haven’t been able to determine the size of these reserves though.
The most recent measurement was made using the ground-based geophysical electromagnetic (EM) approach known as magnetotellurics during the 2018-2019 field season. The researchers analysed fluctuations in Earth’s electric and magnetic fields to assess subsurface resistivity.
Electromagnetic techniques have been used to photograph shallow groundwater beneath some thin glaciers and perennially frozen places in the upper 100 to 200 metres (328 to 656 feet). The researchers used the technique to measure roughly 800 metres at the Whillans Ice Stream. “In most cases, this approach hasn’t been applied in arctic conditions.” “This is a great example of the technique’s potency and how much it can add to our understanding of not only Antarctica, but also Greenland and other glacier regions,” research co-author Helen Amanda Fricker said.
The findings indicated the existence of substantial sediments buried beneath ice and snow from the ice bed to around five kilometres and even deeper.
“The Empire State Building is around 420 metres tall up to the antenna; at the shallow end, our water would go halfway up the Empire State Building.” It’s virtually two Empire State Buildings stacked on top of each other at the deepest end. Because the subglacial lakes in this location are two to fifteen metres deep, this is significant. Gustafson compared it to “one to four storeys of the Empire State Building.”
Groundwater may develop under comparable conditions on other planets or moons that are leaking heat from their innards, according to researchers.