Scientists discover strange holes off the coast of US but don’t know how they got there

Thousands of strange holes have been found off the coast of California, but researchers haven’t figured out how they got there.

Scientists have discovered thousands of mysterious holes in the seabed off Big Sur, California.

Researchers from the Monterey Bay Aquarium Research Institute (MBARI) were surveying the deep sea floor off Big Sur when they discovered the strange holes.

The larger holes, described as pockmarks, are on average about 180 metres across and almost five metres deep. In a statement, MBARI noted that it first discovered some of the pockmarks in 1999. However, subsequent surveys by MBARI and other organisations have revealed more than 5200 pockmarks spread across 1300 square kilometres.

A computer-generated 3D view of a micro-depression. The image was created using underwater video from an underwater drone. Image: Ben Erwin © 2019 MBARI

Thousands of smaller holes, known as micro-depressions. have been discovered. Researchers have spotted around 15,000 micro-depressions that are, on average, around three metres across and one metre deep.

The discovery was described by MBARI researchers Eve Lundsten and Charles Paull at the Fall Meeting of the American Geophysical Union in San Francisco.

“The pockmarks and micro-depressions in this area are both holes in the sea floor that occur in softer sediments, but they are morphologically distinct,” said Ms Lundsten in the statement.

Sea floor map showing pockmark and micro-depressions in the sea floor off Big Sur. Image: © 2019 MBARI

“The cause and persistence of the pockmarks still remains a mystery, but we find no evidence they were created from gas or fluid in the sea floor in the recent past. The micro-depressions are recently formed erosional features; they are not ‘incipient pockmarks’. Overall, a lot more work needs to be done to understand how all these features were formed, and this work is in progress.”

Scientists are keen to understand how the holes formed in the seabed because the area where they were found is the site of a proposed wind farm.

A close-up view of a micro-depression, showing trash, rocks, sea floor animals and fish. Image: © 2019 MBARI

In a separate study revealed at the Fall Meeting of the American Geophysical Union, researchers gave fresh insight into the site of a “nuclear battlefield” by mapping test craters and sunken warships at Bikini Atoll in the Pacific.

Last year, scientists announced the discovery of a stunning volcanic “lost world” off the coast of Tasmania.

This article originally appeared on Fox News and was reproduced with permission