Satellites used to re-investigate whale stranding

Scientists developing techniques to count great whales from space say the largest ever recorded mass stranding event was probably underestimated.

The carcasses of 343 sei whales were spotted on remote beaches in Patagonia, Chile, in 2015 - but this survey work was conducted from planes and boats, and carried out many weeks after the deaths actually occurred.

However, an analysis of high-resolution satellite images of the area taken much closer in time to the stranding has now identified many more bodies.

Dr Jennifer Jackson from the British Antarctic Survey spoke with our science correspondent Jonathan Amos.