The ice sheet at the South Pole of the earth is 4.8 kilometers thick. The pressure of the ice layer can lower the freezing point of the water and the temperature at the bottom of the ice sheet allows liquid water to exist. Radar waves can be used to detect the liquid water under the Antarctic ice sheet. Radar actively emits electromagnetic waves and accepts reflected echoes. Electromagnetic waves of different frequencies have different penetration capabilities. The lower the frequency is, the greater the penetration depth is. When electromagnetic waves travel downward through the ice, they will reflect echoes at the interface between different substances, such as ice and bedrock, water-bearing sediment and the interface between liquid water. The radar moves along the flight orbit and constantly measures the echo. Get an underground image.
tent with the original text?
There must be life at the bottom of the Antarctic ice sheet.