Giant Antarctic lakes discovered: In 2006, scientists reported the discovery of two giant lakes buried more than 4 kilometres beneath Antarctica's ice sheet, revealing vast bodies of liquid water that remained unfrozen beneath one of the coldest environments on Earth, as per a report.The findings identified the second- and third-largest known subglacial lakes in Antarctica after Lake Vostok. Researchers said the lakes may harbor unique ecosystems that have remained untouched for about 35 million years, as per a Livescience report.Hidden lakes beneath Antarctica's iceBefore the discovery, scientists knew of at least 145 smaller lakes beneath Antarctica's ice, along with the massive Lake Vostok.The newly identified lakes, named 90°E Lake and Sovetskaya Lake, were found beneath more than 2 miles (about 4 kilometres) of ice. Researchers estimated that both lakes are about half a mile deep.The larger of the two covers about 770 square miles, roughly the size of Rhode Island, while the other spans about 620 square miles.MORE STORIES FOR YOU✕« Back to recommendation storiesI don't want to see these stories becauseThey are not relevant to meThey disrupt the reading flowOthersSUBMITScientists combined multiple technologies to find themRobin Bell of the Lamont-Doherty Earth Observatory and Michael Studinger made the discovery by combining data from ice-penetrating radar, gravity surveys, satellite imagery, laser altimetry and records from a Soviet Antarctic Expedition that unknowingly crossed the lakes in 1958 and 1959, according to the Livescience report.According to Bell, the pull of gravity above the lakes was noticeably weaker because of the large cavities filled with water beneath the ice.The lakes' shorelines also appeared as subtle surface disturbances in satellite images, while radar data showed slight depressions where the ice floated above the water.Why the lakes never frozeDespite air temperatures that can fall to minus 112 degrees Fahrenheit during the Antarctic winter, the water at the top of both lakes remains at about 28.4 degrees Fahrenheit.Researchers said heat rising from below the Earth's surface, combined with the thick layer of insulating ice above the lakes, prevents the water from freezing, as per Livescience report.Ancient ecosystems may exist below the iceResearchers said the lakes are bounded by faults, and evidence suggests water circulates within them while receiving nutrient flows.These conditions could support unique ecosystems that have remained untouched for about 35 million years beneath Antarctica's ice.The discovery was detailed in the February issue of Geophysical Research Letters.