Deep in the waters along a volcanic ridge in the bottom of the Atlantic Ocean, sea explorers using a remotely operated vehicle to examine largely unexplored areas found a pattern of holes in the sand.
Great ideas re: origin of mysterious holes seen at 2,540 m (1.6 mi) depth during #Okeanos Voyage to the Ridge 2022! This wasn't 1st time these were seen & while scientists aren't sure how holes formed, they suspect their origin is likely biological: https://t.co/yGpbuz7phP pic.twitter.com/dOuIjPlHX9
— NOAA Ocean Exploration (@oceanexplorer) July 27, 2022
"The origin of the holes has scientists stumped," said the post on Twitter from the National Oceanic and Atmospheric Administration's Ocean Exploration project. "The holes look human made, but the little piles of sediment around them suggest they were excavated by … something."
Nearly two decades ago, just about 27 miles away from the location of the current expedition's initial sighting, scientists spotted similar holes during an exploration, said Emily Crum, a NOAA spokesperson.
But the passage of time has not provided any clear answers, said Michael Vecchione, a NOAA deep-sea biologist who participated in that project and is also involved in part of this latest expedition.
"There is something important going on there, and we don't know what it is," Vecchione said. "This highlights the fact that there are still mysteries out there."
The holes are but one of the questions that scientists on an ambitious ocean expedition are probing as they explore the Mid-Atlantic Ridge, which is a section of a massive deep-ocean range of mountains and stretches for more than 10,000 miles beneath the Atlantic Ocean.
Experts with NOAA are seeking answers during three expeditions that they are calling Voyage to the Ridge 2022, which began in May and will conclude in September, in journeys that are taking them from the waters off Newport, Rhode Island, to the Azores and back to Puerto Rico in the Caribbean.
Explorers want to know what lives along the continuous range of underwater volcanoes and what happens when geologic processes that create life-supporting heat are halted.
They are paying close attention to deep-sea coral and sponge communities, which are "some of the most valuable marine ecosystems on Earth," said Derek Sowers, an expedition coordinator aboard the NOAA ship, the Okeanos Explorer.
Annnnnd we're on the bottom! Join us as we explore within the Mid-Atlantic Ridge North of the Azores (aka "MARNA") marine protected area: https://t.co/PhIY0PEDEd pic.twitter.com/LX2vF7YVjP
— NOAA Ocean Exploration (@oceanexplorer) July 20, 2022
Sowers said that expeditions such as the Voyage of the Ridge projects were "fundamental" to establishing an understanding of the biodiversity of the planet and "the novel compounds produced by all of these life-forms".
And they want to know more about areas where seawater is heated by magma, with deep-sea life deriving energy from this source and chemicals, instead of the sun, like most life on Earth.
"This has expanded our understanding of under what conditions life on other planets may occur," Sowers said.
After the agency turned to social media in an effort to engage the public, dozens of comments streamed in, with some delving into speculation. Are the holes human-made? Could they be a sign from extraterrestrials? Are they tracks left by a submarine? Could they be the breathing holes of a "deep sea creature that buries itself under the sand?"
That last guess was not necessarily so far-fetched, Vecchione said. In a paper about the holes spotted in 2004, Vecchione and his co-author, Odd Aksel Bergstad, a former researcher at the Institute of Marine Research in Norway, proposed two main hypotheses for why the holes exist. Both involved marine life, either walking or swimming above the sediment and poking holes down, or the inverse scenario, burrowing within the sediment and jabbing holes up.
The holes seen Thursday appeared to have been pushed out from underneath, Vecchione said.
The remotely operated vehicle's suctioning device collected sediment samples to examine whether there was an organism inside the holes, Sowers said.
Vecchione said that while he was pleased about encountering the ocean floor holes again, he was "a little disappointed" that scientists still lacked an explanation.
"It reinforces the idea that there is a mystery that someday we will figure out," he said. "But we haven't figured it out yet."
One last dive, which will be livestreamed, remains to be carried out in the second expedition of the series, NOAA said. The third expedition begins on August 7.
This article originally appeared in The New York Times.
Written by: Christine Chung
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