Tag Archives: seafloor

Scientists find evidence of ocean crust microbes living beneath the seafloor

Microbiologist Ginny Edgcomb (left) and Gaëtan Burgaud cultured fungal colonies from rock samples deep within the seafloor. Credit: Tom Kleindinst, © Woods Hole Oceanographic Institution.

Scientists have found evidence of active microbial communities living in the oceanic crust hundreds of meters beneath the seafloor, proving that life can find a way under even the most extreme and remote conditions.

Rock cores drilled from an undersea mountain in the Indian Ocean revealed that bacteria, fungi, and single-celled organisms called archaea live in cracks and fissures in the dense rock of the ocean’s lower crust. The scientists discovered that the rock samples contained biosignatures of life, including DNA and lipid biomarkers, and messenger RNA extractions showed that some of the cells were actively dividing.

Beneath the soft sediments of the seafloor sit layers of basaltic and gabbro rocks that make up the oceanic crust. Scientists know that life exists in seafloor sediments, but only one previous study in the Atlantic Ocean probed the oceanic crust for signs of life. In the latest research, scientists recovered rock from 750 meters into the lower crust and performed a host of laboratory tests in search of microbial activity.

Beneath the soft sediments of the seafloor sit layers of basaltic and gabbro rocks that make up the oceanic crust. Scientists know that life exists in seafloor sediments, but only one previous study in the Atlantic Ocean probed the oceanic crust for signs of life. In the latest research, scientists recovered rock from 750 meters into the lower crust and performed a host of laboratory tests in search of microbial activity.

“These [communities] can basically be hanging out for millions of years in a very quiescent state,” study author and associate scientist Virginia Edgcomb, from Woods Hole Oceanographic Institution, said. “I’m sure even the active microbes are carrying on at a very slow rate relative to those near the surface, but nevertheless, they’re buzzing along.”

The latest research, published today in the journal Nature, suggests that survival in the deep biosphere depends on underground fluid flow. As seawater entrains deep in the crust, it travels through cracks in the rock, some microfine and others as large as, or even larger, than spaghetti noodles. The fluid likely carries organic matter from the ocean, said Edgcomb, and the team found signs of life clustered around these nutrient highways.

A thin section of the rock core shows distinct minerals (colored) and a small cavity where fluid may have flowed through, delivering organic matter that fuels subsurface microorganisms. Credit: Frieder Klein/WHO.

Many of the microorganisms match those observed in other extreme environments, like hydrothermal vents, said Edgcomb. But unlike what Edgcomb expected, the underground life relied on both fixing chemicals for energy and co-opting organic matter floating in the fluid. Messenger RNA analysis revealed that the microbes can recycle amino acids or lipids of dead (or even living) matter. Steven D’Hondt, a professor at the University of Rhode Island who was not involved with the research, said this “runs counter to standard assumptions about subseafloor crustal life.”

“The readiness of that community to consume organic matter suggests that it is metabolically linked to the broader world (e.g., the ocean) via ocean circulation,” D’Hondt said.

It’s unclear whether these results can apply to other areas of the ocean’s lower crust. The research team extracted cores from the undersea mountain Atlantis Bank where the lower crust is exposed at the ocean bottom, which is unusual—normally, thousands of meters of sediment would cover it. The site gave the research team unprecedented access to the lower crust, but future research must confirm whether life is possible with upper crust and bottom sediments still intact.

The latest study shows that “life finds a way,” said Jennifer Biddle, an associate professor at the University of Delaware who did not take part in the study. Earth’s lower oceanic crust could be an analogue to how life might survive on other planets, Biddle added.

Edgcomb cautions that the biomass in the study was extremely low: The cells are just “barely eking out a living,” she said. Still, “the lower ocean crust is one of the last frontiers of the exploration for life on Earth,” Edgcomb said. “We have a better understanding that the lower crust does indeed host viable and, in some cases, active microbial cells.”

—Jenessa Duncombe (@jrdscience), Staff Writer

This article was originally published on Eos Magazine and was republished under a CC BY-NC-ND 3.0 license.

Rare earth deposit Japan.

Japan stumbles upon massive, “semi-infinite” underwater treasure trove of rare earth elements

Deep-sea deposits found off the coast of Japan could supply the global demand for rare earth elements virtually forever, according to a new study. The deposit is estimated to hold more than 16 million tons of rare earth elements.

Rareearthoxides.

Rare earth element oxides.
Image credits Peggy Greb / US department of agriculture / Wikimedia.

Japanese researchers have mapped a huge deposit of some of today’s most valuable and economically-vital resources: rare earth elements. There should be enough of them lodged in deep-sea muds within Japan’s exclusive economic zone waters to feed global demand on a “semi-infinite basis,” they report.

Sunken booty

Rare earth metals are key to producing high-tech products: everything from smartphones to electric vehicles requires some amount of these elements to function, and we don’t know of any viable substitutes we can swap them for. As their name implies, they’re also quite rare. Taken together, these two facts make these materials highly sought-after, and quite expensive.

Currently, the world relies on China to supply most of the rare earth elements on the market. However, this often raises problems: Beijing has shown itself willing to block the export of these products during times of diplomatic tension. For example, back in 2010, China severely limited the quantity of these elements it exported to Japan following the arrest of the captain of a Chinese trawler. He had a run-in with the Japan Coast Guard near the Japan-administered Senkaku Islands, which are also claimed by China.

Japanese manufacturers had to suffer massive rare earth element shortages in the aftermath of the incident, a move that essentially amounted to China wielding the minerals as a diplomatic cudgel in a border dispute.

Considering this, the discovery of the massive deposits — in Japan’s exclusive economic zone, no less — is bound to make Tokyo happy, and raise worry in Beijing.

Mud-cheap technology

Rare earth deposit Japan.

The deposit’s location.
Image credits Scientific Reports.

However, for us, that’s neither here nor there. What is important to us is the sheer estimated size of this deposit — which, for us as consumers, should translate to much lower costs once extraction begins at the site

The team, comprised of several universities, businesses, and government institutions, surveyed the western Pacific Ocean near Minamitori Island and estimated that a single sample area of the deposit contains more than 1.2 million tons of “rare earth oxide” — i.e. rare earth element ores.

The study, conducted jointly by Waseda University’s Yutaro Takaya and the University of Tokyo’s Yasuhiro Kato, extrapolates that the whole 2,500-sq km deposit area should contain 16 million tons of the valuable elements, and concludes that “has the potential to supply these metals on a semi-infinite basis to the world”. That’s equivalent to 780 years’ worth of yttrium supply, 620 years of europium, 420 years of terbium and 730 years of dysprosium, it added.

If the estimations prove true, the deposit could cover the world’s requirements for these elements for hundreds of years to come. The researchers also detail a new and more efficient method of refining the valuable elements from the mud, which should make them even cheaper on the global market.

“The enormous resource amount and the effectiveness of the mineral processing are strong indicators that this new (rare-earth rich mud) resource could be exploited in the near future,” the study said.

The paper “The tremendous potential of deepsea mud as a source of rare-earth elements” has been published in the journal Scientific Reports.

Melting ice is causing the ocean to sink, worrying new study reports

Scientists have identified yet another unexpected consequence of climate change: warming temperatures are causing polar ice to melt, and this extra weight is causing the ocean floor to sink. This process also exacerbates sea level rise.

Image credits: Lieberum / Pixabay.

Much like an octopus, the arms of climate change are long, far-reaching, and sticky. If there’s one thing recent studies have shown, it’s that rising temperatures are causing a myriad of planetary changes, often with unforeseeable effects. For instance, climate models clearly showed that rising temperatures will melt polar ice. But it’s much harder to predict the effects that this extra water will have on the rest of the Earth’s systems.

Now, geoscientist Thomas Frederikse from the Delft University of Technology in the Netherlands and his colleagues report that the meltwater is adding extra weight to the seafloor.

We tend to think of the Earth as a firm, unchangeable sphere. But geologically, our planet is a very dynamic place.

“The Earth itself is not a rigid sphere, it’s a deforming ball,” Frederikse said. “With climate change, we do not only change temperature.”

Researchers had known that extra weight could cause the Earth to become squashed, but they wanted to know how much it could be squashed — and this is where the surprises started.

Changes in a) the seafloor b) relative sea level and c) sea level as measured by satellites when considering the effect of additional ocean mass on the seafloor height. Note how sea level change relative to the seafloor is actually negative for the Arctic—that’s because the seafloor is rising slightly due to mass loss. Image: Frederikse et al. 2017

They found that the effect is so pronounced that current models are slightly off, and sea level rise is even more significant than we expected. The measuring problem comes from the fact that satellite altimeters measure the height of the ocean surface relative to the center of the Earth, but they don’t see what’s happening with the seafloor. So researchers needed a different type of data.

“We have had tide gauge sea level rise measurements for more than a century,” Frederikse told Earther. “You put an instrument at the sea bottom and see how far sea level changes relative to the bottom. Satellites orbiting the Earth measure sea level from space. We wanted to see how large is the difference.”

Frederikse’s team analyzed data from Greenland and Antarctica ice sheets, as well as changes in water storage on land surfaces due to dams, irrigation, and other human activities. After a lot of number crunching and modeling, they found that the extra load on the oceans was significant enough to cause an extra sinking of 0.1 mm/yr between 1993 and 2014, or 2.1 mm over the entire period. This drop wasn’t uniform, reaching 1 mm/yr over the Arctic Ocean and 0.4 mm/yr in the South Pacific.

This might not seem like much, but this is the entire ocean we’re talking about. There’s no immediate reason to worry, but when you consider the sheer scale of the process, it does raise a red flag. The phenomenon is also expected to increase in intensity as more and more ice starts to melt.

For scientists, this study also suggests that there’s a significant error source when it comes to sea level rise — it’s an 8% amplification effect which we haven’t considered until now.

“The effect is systematic and relatively easy to account for,” Frederikse and his co-authors write in their study published recently in Geophysical Research Letters, adding that it’s likely to become a more obvious issue as climate change progresses. “In a future warming climate, the sea level rise induced by ice sheets will increase, and therefore, the magnitude of the bias due to elastic ocean bottom deformation will grow.”

Taking a step back and looking at the bigger picture, there’s a clear message behind this study: mankind’s effect on the planet is profound and long-lasting, affecting every ecosystem on the planet. Ocean floor deformation turned out to be an impactful and unexpected process, who knows what else we’re missing?

The study was published in Geophysical Research Letters.

 

The auxiliary cutter.

First deep-sea mining operation scheduled to start in 2019 — here are the bots that will do it

Canadian-based firm Nautilus Minerals Inc. plans to launch the world’s first deep sea mining operation in early 2019. The company will launch three remote-controlled mining robots off the coast of Papua New Guinea to the floor of the Bismark Sea to mine rich metal deposits.

Each of the robots is the size of a small house and equipped with huge rock-crushing, teeth-riddled devices to chew through the ocean’s bottom. The smallest one weighs 200 tons and they will be propelled from spot to spot on huge threads in their search for paydirt.

The auxiliary cutter.

The first bot, known as the auxiliary cutter, clears the way for the other two to operate.
Image credits Nautilius Minerals Inc.

“A lot of people don’t realize that there are more mineral resources on the seafloor than on land,” Michael Johnston, CEO of Nautilus,  said for Seeker. “Technology has allowed us to go there.”

Pressed by looming shortages on one hand and the prospect of lucrative exploitations on the other, companies and governing bodies have started joining hands to bring sea-bed mining into the picture. To date, over twenty exploration contracts have been issued by the International Seabed Authority (ISA), a part of the UN tasked with regulating areas of the seafloor that lie outside of any national jurisdiction.

“In the seabed, resources are incredibly rich,” said Michael Lodge, Secretary-General of the ISA. “These are virgin resources. They’re extremely high-grade. And they are super-abundant.”

We’ve recently talked about how current levels of mining exploration and exploitation just won’t be able to supply future demand. As populations grow and economies develop, current raw material exploitations will need new additions to satisfy that extra demand. There’s also the need to create a strong mining base to support the development of low-carbon economies — which rely on technology materials that are in short supply currently.

Seabed mining offers an attractive solution to this problem: untouched resources just waiting to be taken in the form of massive sulfide deposits of copper, nickel, cobalt, gold, and platinum.

“It’s no exaggeration to say that there are thousands of years’ supply of minerals in the seabed,” Secretary-General Lodge said. “There is just absolutely no shortage.”

The Auxiliary Cutter.

The Auxiliary Cutter removes rough terrain and creates benches for the other machines to work on.
Image credits Nautilius Minerals Inc.

Nautilius says that early tests in the Bismark Sea site, have shown the area is over 10-times as rich in copper as comparable land-based mines, and has more than three times the concentration of gold than the average figure of land exploitations. These fantastic numbers generally come down to the fact that surface resources have been thoroughly explored and long exploited, meaning that the richest deposits on land aren’t around anymore — they’re now cars, or copper wires, or planes. So by comparison, the deposits locked on the sea floor look like a cornucopia of resources just waiting to be harvested.

And I’m all for that. Considering the need, it may not be a question of ‘do we want to exploit the sea floor’ but rather one of ‘how are we going to make it if we don’t?’ That being said, we’ve had a lot of time and opportunities up here on dry land to see what rampant exploitation without care for the places being exploited leads to. As the idea of seabed mining comes closer to reality, we should really think about what the consequences of our actions would be — and how not to make a mess down there as we did topside. Some think that we’re better off just banning the practice altogether.

“There are too many unknowns for this industry to go ahead,” said Natalie Lowrey of the Australia-based Deep Sea Mining Campaign. “We’ve already desecrated a lot of our lands. We don’t need to be doing that in the deep sea.”

“There’s a serious concern that the toxicity from disturbing the deep sea can move up the food chain to the local communities [who live along the coast of Papua New Guinea].”

The Collecting Machine.

The Collecting Machine gathers cut material by drawing it in as seawater slurry with internal pumps and pushing it through a flexible pipe to the riser and lifting system.
Image credits Nautilus Minerals Inc.

One of her main concerns is that plumes of sediment stirred up during mining operations will travel along sea currents and interfere with ocean ecosystems. The clouds of silt could prove harmful to filter-feeders which often form the lower brackets of food chains — so a hit here would impact all other sea creatures.

Michael Johnston said that the company is taking the sediment plume issue seriously and have designed their equipment to minimize any undersea clouding generated by the collection procedure.

“When we’re cutting, we have suction turned on,” he said. “It’s not like we’re blowing stuff all over the place. We’re actually sucking it up. So the plume gets minimized through the mining process.”

“We go to great efforts to minimize the impact of the plumes. We’re quite confident that the impact from these activities will be significantly less than some of these people claim.”

Still, going forward we should primarily be concerned with not messing stuff up that much — because as we’ve seen, there’s no such thing as a free meal. We’ll have to wait and see how it all develops. In the meantime, one thing is certain.

“If Nautilus goes ahead, it’s going to open the gateway for this industry,” Lowrey concludes.

Underwater maintenance robot-snakes look scary but are actually quite cool

Eelume  developed a snake-like robot for underwater maintenance tasks. The deceptively simple robots could drastically reduce operating costs for deep sea rigs.

Image via youtube

Remember “Terminator”? Or that diamond of modern cinema, “Snakes on a Plane”? Both terrifying in very different ways. Now scientists, not content to be one-upped by mere movies, mixed the two together into a whole new blood curling package — underwater robot snakes.

Admittedly they’re not out to hurt anyone. In fact, they’re here to help: the Eelume bots were developed to maintain underwater equipment in working order, an otherwise very pricey task. They will be permanently deployed on the seabed, where they will tend to gear that is difficult and expensive to reach for human personnel.

The robot is designed with this snake-like form so it can slither in and around underwater rigs to clean and perform quick visual inspections. The robot’s head can clamp down on small components so it can perform tasks such as adjusting valves, for example.

Eelume, the company behind this project, is a spin-off company out of the Norwegian University of Science and Technology (NTNU). It collaborated with oil and gas company Statoil and Norway’s Kongsberg Maritime in developing the robot. The latter — with over 25 years experience, including operating the robot that captured the Sherlock Holmes movie model of the Loch Ness monster last week — lent its underwater robot know-how to the project, while Statoil provided real-life installations for testing.

The developers hope that the robot snakes can take over the bulk of subsea inspection tasks, drastically reducing the need for costly vessels. Eelume stated that the bots can be permanently deployed to both new and existing underwater systems, where they will serve as a “self-going janitor on the seabed.”

The videos below show how the snakebot swims, both with thrusters attached and just with slithering motions. For now, they require a cable connection to a surface power supply, but this is presumably for test purposes only.

Huh, they’re actually quite awesome. Can I have one as a pet?

Story source Kongsberg.

Rare Earth minerals to be mined from the seafloor

The next step in prospecting and mining has always been a subject of speculation and theories, ever since the days of Jules Verne. For decades, an idea that flourished more and more was to gather up potato-sized magnanese nodules, rich in nickel, cobalt and manganese, that are very valuable in large quantities. The problem is that pretty much all the time, they lie miles below the seafloor, which obviously poses some serious technical questions.

The classical idea of building giant vacuums to suck up the nodules never proved to be economically sustainable; however, it was recently discovered that these modules are have a high content of rare earth minerals, elements that have a high demand rate but have recently reached a production roadblock. China, which controls about 95% of the worldwide quantity had stopped seeling them, creating huge political and industrial alarms; they stopped the embargo a few weeks ago, but the hunt for other sources still continues – this could give the seabed miners quite a few reasons to smile and rub their hands.

“People are quite intrigued,” said James R. Hein, a geologist with the United State Geological Survey who specializes in seabed minerals. Depending on China’s behavior and the global reaction, he said, “rare earths may be the driving force in the near future.”

About a month ago, Dr. Hein and five colleagues from Germany presented a paper on harvesting the nodules for rare and valuable metals, and concluded that there really is something there.

“They really do add value,” Charles L. Morgan, chairman of the institute, said of the rare earths in an interview. The result, he added, is that the nodules have taken on a new luster. “People are starting to think, ‘Well, maybe these things aren’t so dumb after all.’ ”

Rare earths are quite interesting from a number of perspectives; most of them are not really rare at all, but they rarely gather up in large quantities; some of them are practically neglectable. For example, an isotope of Promethium has only 572 g in the entire Earth’s crust. Right now, they really aren’t extremely important, but things could change pretty quick, especially with the current unstable political situation.

“The global activity is tremendous,” said Dr. Hein of geological survey, referring to undersea exploration as well as processing assessments on land. “Right now, rare earths are not the driving force,” he said. “But for copper and nickel, the prices are there.”