As far as discoveries go, this one is literally huge: An aquifer holding more than 100 billion tons of water that covers an area larger than West Virginia has been discovered beneath Greenland's snow-covered ice sheet. And it caught the researchers who stumbled on it in 2011 off-guard, with lead study author Richard Forster telling LiveScience, "We thought we had an understanding of how things work in Greenland, but here is this entire storage system of water we didn't realize was there." As for the "where," the aquifer was identified in the southeast part of the country, ranging from 15 to 160 feet beneath the surface, whose snow acts as an insulator, keeping the water liquid year-round. Forster gives this great description of how the water is stored, per the BBC: "in the air space between the ice particles, like the juice in a snow cone."
But the find has raised plenty of questions, like: How old is the water? Does it stay where it is, or trickle to the sea ... or rush toward the sea in a flood? In a separate study, the team determined that if released, the aquifer's water could push global sea levels up 0.015 inches. And in terms of sea level rise, LiveScience explains that scientists have long assumed that most of the water produced in the country's annual surface melt streams toward the ocean, or eventually refroze; the aquifer is essentially a "new hiding place," one that researchers can study to get a better grasp on the annual melt. Says Forster, "We need to understand it more completely if we are to predict sea level rise."