Fact No.172

Given their sheer volume, ninety-nine percent of the living space on the planet is found in the oceans. The average depth of the oceans is 2.5 miles (4 km). The deepest point lies in the Mariana Trench, 6.8 miles (10.9 km) down. By way of comparison, Mount Everest is only 5.5 miles (8.8 km) high.