X Prize challenges ocean mappers

There is a new X Prize to accelerate technologies to explore the ocean.

Shell is sponsoring the competition, which will challenge teams to map a 4km-deep, 500-sq-km area of sea floor using autonomous robots.

The award, which is valued at $7m (£4.6m), will have to be claimed before the end of 2018.

X Prize technical director Dr Jyotika Virmani told our correspondent Jonathan Amos why such an incentive was required.