A massive underground reservoir of fresh water lying deep below Utah’s Great Salt Lake could hold the answer to one of the most pressing environmental crises, according to a new study.
WHAT DID SCIENTISTS FIND?
Researchers at the University of Utah have found that freshwater saturates the rock and sediment beneath the Great Salt Lake to depths of up to 13,000 feet.
Using helicopter-mounted electromagnetic equipment, the team essentially “X-rayed” the ground beneath Farmington Bay, one of the lake’s eastern sections, to map out where fresh water ends and salty brine begins.
“We were able to answer the question of how deep this potential reservoir is, and what its spatial extent is beneath the eastern lake margin. If you know how deep, you know how wide, you know the porous space, you can calculate the potential freshwater volume,” said Michael Zhdanov, a professor of geology and geophysics who led the research.
HOW WAS THE OCEAN FOUND?
The breakthrough came after scientists noticed something odd. They noticed circular mounds of tall reeds sprouting up on the dried-out lake bed.
These reeds were being fed by freshwater bubbling up from underground, under pressure.
The observation sparked curiosity and the researchers flew a helicopter carrying special electromagnetic sensors across almost 248 kilometres of the lake.
The equipment could tell fresh water from salty brine because salt water conducts electricity far more easily.
As Zhdanov put it: “Red means very conductive, blue is resistive. You clearly see near the surface is saline water. 10 meters underneath is resistive freshwater. You see clearly it’s everywhere.”
Although the study covered only a small portion of the vast water body, Zhdanov believes his team can survey the entire lake’s area, which is approximately similar to over 5.4 lah football fields.
WHY DOES IT MATTER?
As the Great Salt Lake has shrunk, it has left behind over 2000 square kilometres of dry, cracked lakebed. Winds whip up toxic dust from this exposed surface and blow it into nearby cities.
This underground freshwater could be used to dampen those dust hotspots, said hydrologist Bill Johnson, a co-author on the study.
“To me, that’s a primary objective because it’s very practical,” he added, “And it’s unlikely we’ll be able to fill Farmington Bay and other parts of the playa enough to avoid some dust spots appearing at the higher elevations. This would be a great way to get at that.”
