Ask Smithsonian: Why Are Lakes Freshwater and Oceans Saltwater?

Erosion, evaporation, and a leaky faucet, our host Eric Schulze breaks it all down. (1:15 )

Ask Smithsonian is a weekly video series that unravels some of science's most surprising mysteries. The series is made possible through the support of GEICO. Smithsonian members could save even MORE with a special GEICO #MemberDiscount on auto insurance.

Have a question in mind? It's your turn to Ask Smithsonian.

Latest Videos

Preview thumbnail for video'Incredible: Five Lions Take Down a Giraffe
Incredible: Five Lions Take Down a Giraffe (2:49)
Preview thumbnail for video'Ask Smithsonian: Can Animals Predict Earthquakes and Other Natural Disasters?
Ask Smithsonian: Can Animals Predict Earthquakes and Other Natural Disasters? (1:27)
Preview thumbnail for video'Utah's Otherworldly Landscapes
Utah's Otherworldly Landscapes (2:20)
Preview thumbnail for video'John Muir's Transformative Climb Up Mt. Rainier
John Muir's Transformative Climb Up Mt. Rainier (1:47)
Preview thumbnail for video'A Secret Refuge for Elk Thought to Be Extinct
A Secret Refuge for Elk Thought to Be Extinct (2:11)
Preview thumbnail for video'How One Millionaire's Promise Led to a National Park
How One Millionaire's Promise Led to a National Park (3:52)
Preview thumbnail for video'Which National Park Draws 25 Million Visitors a Year?
Which National Park Draws 25 Million Visitors a Year? (3:32)
Preview thumbnail for video'Secret Refuge of the Swamp Fox
Secret Refuge of the Swamp Fox (1:48)
Preview thumbnail for video'The Double Eagle Investigation
The Double Eagle Investigation (3:00)