The antarctic ice sheet in the southern hemisphere

holds almost two-thirds of earth’s fresh water
contains almost one-fourth of the world’s ice
is the only ice sheet remaining on the planet
holds almost two-thirds of earth’s salt water

The answer is it holds almost two-thirds of Earth’s fresh water. It also holds approximately 2% of the world's total water supply (this includes salty water) Antarctica is the largest ice sheet in the world, after the Arctic, which forms a whole continent. If Antarctica were to completely melt, the oceans levels would rise by approximately 60 meters.