Book 14, Question 115
How Can Scientists Use Sound to Measure How Thick Ice Is?
Scientists can measure how thick ice is by sending sound into it and timing the echo! A short pulse of sound goes down and bounces off the bottom of the ice. The longer the echo takes, the thicker the ice.
More fun facts
- In 2016, British Antarctic Survey scientists measured Larsen C Ice Shelf in West Antarctica using a hammer hitting a plate as their sound source.
- The returning echoes were recorded on 24 receivers set 10 metres apart.
- Echoes from the seabed under the floating ice showed up at every site they tested.
- If no echo comes back from the bottom of the ice, scientists can estimate its thickness from how high the ice surface sits.
- On the Filchner-Ronne Ice Shelf, scientists made 256 point seismic measurements over three seasons, and 248 had clear echoes they could use.
- Each of those points gives both the thickness of the ice and the depth of the water under it.
Questions kids ask
Is it safe to walk on ice that scientists measure?
Scientists in Antarctica work on very thick ice shelves. Never walk on a frozen pond unless an adult says it has been checked.
Why use sound instead of drilling?
Sound lets scientists check the ice at many places without drilling a hole all the way through it.