Blood Falls, in East Antarctica’s McMurdo Dry Valleys, looks like slowly pouring scarlet-red blood, staining snowy white Taylor Glacier and Lake Bonney below.
The trickling crimson liquid isn’t blood, however. Nor is it water dyed by red algae, as early Antarctica pioneers first speculated. In fact, the brilliant ochre tint comes from an extremely salty sub-glacial lake, explains Quora user Aditya Bhardwaj.
About two million years ago, a hyper-saline body of water became trapped beneath Taylor Glacier, isolated from light, oxygen and heat. As the saltwater trickles through a fissure in the glacier, it reacts with the oxygen in the air to create this spectacular, rust-hued cascade.