By: William Liao
It’s estimated that only around five percent of the ocean has been explored by humans, especially the depths of the sea floor. By contrast, humanity has conquered the highest mountains and even the moon, and it is often said that we know more about the surface of Mars than the ocean. Which begs the question – what really goes on down there?
The history of deep-sea exploration is relatively short, but recent technological advances have deepened our understanding of the ocean, which covers around seventy percent of Earth’s surface. So, scientists were intrigued when an unmanned, remotely operated vehicle exploring a region of the Atlantic Ocean north of the Azores discovered dozens of sets of holes arranged in what seemed like lines at a depth of 1.6 miles on the ocean floor.
The voyage is one of three expeditions, collectively known as Voyage to the Ridge 2022 and run by the National Oceanic and Atmospheric Administration. The expeditions began in May and are scheduled to run through September, and will set sail from Newport, Rhode Island to the Azores Plateau, an underwater meeting point of three tectonic plates off the Azores, a group of islands administered by Portugal. After it has completed its mission, it will then head back to Puerto Rico, an American territory in the Caribbean Sea.
The goal of the expedition was to find out what exactly lives along the Mid-Atlantic Ridge, an underwater mountain range stretching nearly ten thousand miles. In addition, it has also seeked to learn more about how magma-heated seawater can serve as an alternative to the sunlight which supports life above the surface, and what happens when these life-giving geologic processes are halted.
“This has expanded our understanding of under what conditions life on other planets may occur,” Derek Sowers, an expedition coordinator for NOAA, said.
The recent sightings were not the first of their kind. Two decades earlier, similar patterns were discovered just 27 miles from the site of the current sightings during a separate expedition, though time, in this case, could not tell what they were.
Scientists have even turned to the public for some possible explanations about the holes, which are spaced roughly four inches apart and stretch for around five to six feet.
“The origin of the holes has scientists stumped,” read a Twitter post from NOAA’s Ocean Exploration project. “The holes look human made, but the little piles of sediment around them suggest they were excavated by … something.”
Some have speculated that the holes, dubbed “lebensspuren,” which is German for “life traces,” were man-made, left by a submarine, or even a sign left by extraterrestrials. But scientists believe that the most plausible theory is that some type of deep-sea creature left the patterns.
In a 2004 paper published after the first sightings of the mysterious phenomenon, Michael Vecchione, a deep-sea biologist working for NOAA, along with his co-author Odd Aksel Bergstad, a former researcher at Norway’s Institute of Marine Research, proposed two hypotheses for why the holes exist. Both involved some sort of deep-sea life, which either poked them from above or below, though the latter seems more likely given the sediment samples collected by the recent expedition.
“There is something important going on there and we don’t know what it is,” Dr. Vecchione said. “This highlights the fact that there are still mysteries out there.”
Dr. Vecchione was disappointed about how scientists continued to lack an explanation, but he still believed that the mystery would one day be cracked.
“But we haven’t figured it out yet,” he added.
Original article: https://www.nytimes.com/2022/07/28/science/holes-ocean-floor-mystery.html