This quiz asks for the ten deepest ocean trenches on Earth. Each trench is marked with a pin on the world map, and you type the name of each one.
Eight of the ten trenches are in the Pacific Ocean. Almost all of them follow the Ring of Fire, where one tectonic plate slides under another and pulls the sea floor down with it.
How to play
The map shows ten pins. Each pin marks one trench.
Type a trench name in the box at the bottom of the screen. The quiz accepts the name as soon as it matches.
A correct name reveals the trench and its greatest depth.
You can name the trenches in any order. Depth order does not matter.
The clock runs until you name all ten trenches, or until you give up.
What counts in this quiz
The ten deepest trenches, measured to the deepest point in each trench.
The name of the deepest point also counts. "Challenger Deep" is accepted for the Mariana Trench, and "Horizon Deep" for the Tonga Trench.
Short forms count. "Mariana", "Kermadec" and "Atacama" are all accepted.
Older names count where they are still in wide use. "Mindanao Trench" is accepted for the Philippine Trench.
What's not included — and why
Troughs and deep basins are not trenches, so they are not in this quiz.
The Sunda Trench and the Cayman Trough are deep, but neither one reaches the top ten.
Depths change a little between surveys. The quiz uses the figure that reference works give most often.
Good to know
The Challenger Deep is about 10,935 m deep. Put Mount Everest in it and two kilometres of water would still cover the summit.
The first crewed dive to the bottom of the Challenger Deep was in 1960. The next one came 52 years later.
The Puerto Rico Trench is the deepest place in the Atlantic Ocean.
The Tonga Trench is also the fastest moving plate boundary on Earth.