Ocean quiz: Earth's least known surface
Most of the seafloor has never been seen by anyone. Eleven questions on depth, salt, tides and the part of the ocean still left unmapped.
The surface of the Moon is mapped in finer detail than the seafloor of our own planet. The ocean covers two thirds of Earth's surface, yet the share of it that humans have actually laid eyes on is surprisingly small.
The answers to these eleven questions come from measurements published by the US National Oceanic and Atmospheric Administration (NOAA). Let's see how many you get.
The Challenger Deep, the deepest known point of the world ocean, lies in which ocean?
Where does the name Challenger Deep come from?
According to the 2010 multibeam sonar survey, how deep is the Challenger Deep?
If Mount Everest were cut off at sea level and dropped into the Challenger Deep, what would happen?
How much of Earth's surface does the Pacific Ocean cover?
How did the Pacific Ocean get its name?
Where does the salt in seawater mainly come from?
Roughly what share of the weight of seawater comes from dissolved salts?
According to NOAA, how much of Earth's oxygen comes from the ocean?
How does the Sun compare with the Moon as a tide-generating force?
How much of the deep ocean seafloor have humans actually seen with their own eyes?
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