Earth's longest mountain range, highest mountain, most spectacular waterfall, and deepest valley lie in the oceans.

The Mid-Ocean Ridge stretches 46,000 miles (74,000 km), more than four times the lengths of the Andes, Rockies, and Himalayas combined §.

Mauna Kea in Hawaii rises 33,465 feet (10,200 m) from the sea floor.

A slow cascade of cold water beneath the Denmark Strait between Greenland and Iceland sinks 2.2 miles (3.5 km), over three-and-a- half times farther than the tallest waterfall on land, Venezuela's Angel Falls §.

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. Mount Everest is only 5.5 miles (8.8 km) high §.

image courtesy of Gene Feldman and Dave Pape, NASA

Ocean Planet Exhibition Floorplan

gene carl feldman ( (301) 286-9428
Judith Gradwohl, Smithsonian Institution (Curator/Ocean Planet)