Mysterious holes on sea floor off California coast finally explained

The cause of a mysterious field of holes in the sea floor off the coast of California has finally been revealed.

Researchers from the Monterey Bay Aquarium Research Institute (MBARI), the US Geological Survey, and Stanford University debunked a previously-held theory that the formations, known as pockmarks, were caused by methane gas eruptions over time.

They say they are instead preserved by sediment flows.

The holes, near Big Sur, span an area that is approximately the size of Los Angeles.