Deep in the waters along a volcanic ridge at the bottom of the Atlantic Ocean, marine explorers using a remotely operated vehicle to survey largely unexplored areas have found a pattern of holes in the sand.
While diving north of the Azores, near the Portuguese mainland, on July 23, they saw about a dozen series of line-like holes on the ocean floor at a depth of 1. 6 miles.
Then about a week later on Thursday there were four more sightings on the Azores Plateau, which is an underwater terrain where three tectonic plates meet. These holes were about a mile deep and about 300 miles from the site of the expedition’s initial find.
The question scientists ask themselves and the public in posts about Twitter and Facebook is: what creates these marks on the bottom of the ocean?
“The origin of the holes leaves scientists puzzled,” said the Twitter post from the National Oceanic and Atmospheric Administration’s Ocean Exploration Project. “The holes look like they were man-made, but the little piles of sediment around them suggest they were dug by… something.”
Nearly two decades ago, about 27 miles from the site of the current expedition’s initial sighting, scientists spotted similar holes while exploring, said NOAA spokeswoman Emily Crum.
But the passage of time hasn’t provided 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.
“Something big is going on there and we don’t know what it is,” Dr Vecchione said. “It highlights the fact that there are still mysteries out there.”
The holes are just one of the questions scientists on an ambitious ocean-going expedition ask themselves, as they explore the Mid-Atlantic Ridge, which is a section of a huge mountain range in the open sea and s stretches over 10,000 miles under the Atlantic. Ocean.
NOAA experts are looking for answers during three expeditions they call Voyage to the Ridge 2022, which began in May and will end in September, in journeys that take them from the waters off Newport, RI, to the Azores and return to Puerto Rico in the Caribbean.
Explorers want to know what lives along the continuous range of submarine volcanoes and what happens when the geological processes that create vital heat are stopped.
They pay particular attention to deep-sea coral and sponge communities, which are “some of the most valuable marine ecosystems on the planet,” said Derek Sowers, expedition coordinator aboard the NOAA vessel, the ‘Okeanos Explorer.
Dr Sowers said expeditions such as the Voyage of the Ridge projects were “fundamental” to establishing an understanding of the planet’s biodiversity and “the new compounds being produced by all of these life forms”.
And they want to know more about areas where seawater is heated by magma, life in the deep sea getting its energy from this source and from chemicals, instead of the sun, like most life forms on Earth.
“It has broadened our understanding of the conditions under which life on other planets can occur,” said Dr Sowers.
After the agency took to social media in a bid to engage the public, dozens of comments poured in, some delving into speculation. Are the holes artificial? Could they be a sign of aliens? Are these traces left by a submarine? Could they be the breathing holes of a”deep sea creature that burrows under the sand?”
That last guess wasn’t necessarily so far-fetched, Dr. Vecchione said. In an article on the holes spotted in 2004, Vecchione and his co-author, Odd Aksel Bergstad, a former researcher at the Marine Research Institute of Norway, offered two main hypotheses as to why the holes exist. Both involved marine life, walking or swimming over sediment and digging holes, or the reverse scenario, digging through sediment and digging holes.
The holes seen on Thursday appeared to have been pushed in from below, Dr Vecchione said.
The remote-operated vehicle’s suction device collected sediment samples to examine whether there was an organism inside the holes, Dr Sowers said.
Dr Vecchione said while he was delighted to encounter the holes on the ocean floor again, he was “a bit disappointed” that scientists still had no explanation.
“It reinforces the idea that there is a mystery that one day we will uncover,” he said. “But we haven’t figured it out yet.”
A final dive, which will be broadcast live, remains to be carried out in the second expedition of the series, NOAA said. The third expedition begins on August 7.