Curated playlist
Bodies of water
- Swimming poolA San Francisco pool was so big that lifeguards needed kayaks. The Fleishhacker Pool opened in 1925 and closed in 1971.
- EstuaryTwenty-two of the world's 32 largest cities, counted in the early 1990s, were built on estuaries.
- Spring (hydrology)A whole creek sinks into the ground in Missouri, then helps feed Mammoth Spring in Arkansas.
- WetlandSince 1900, between 65 and 70 percent of the world's wetlands have been lost. Many were drained for farming.
- BayThe word bay covers both the Bay of Bengal and a cove barely wide enough for a fishing boat.
- LakeWhere does a pond end and a lake begin? Size rules range from 2 to 8 hectares, and no line is agreed.
- FloodA flash flood killed eight people at a canyon waterfall with no observed rain.
- SeaSeawater is too salty to drink because human kidneys cannot make urine as salty as the sea.
- OceanThe ocean still supplies half of Earth's oxygen. It also gave the planet its atmospheric oxygen.
- RiverAbout half of all waterways on Earth never hold a steady flow all year. Some run dry or flow only in certain seasons.