What if the “great ocean garbage patches” were just the tip of the iceberg? While more than 10 million tonnes of plastic waste enters the sea each year, we actually see just 1 percent of it – the portion that floats on the ocean surface. What happens to the missing 99 percent has been unclear for a while.
Plastic debris is gradually broken down into smaller and smaller fragments in the ocean, until it forms particles smaller than 5 mm, known as microplastics. Our new research shows that powerful currents sweep these microplastics along the seafloor into large “drifts”, which concentrate them in astounding quantities.
We found up to 1.9 million pieces of microplastic in a 5 cm-thick layer covering just one square metre – the highest levels of microplastics yet recorded on the ocean floor.
While microplastics have been found on the seafloor worldwide, scientists weren’t sure how they got there and how they spread. We thought that microplastics would separate out according to how big or dense they were, in a similar manner to natural sediment. But plastics are different – some float, but more than half of them sink.
Plastics which once floated can sink as they become coated in algae, or if bound up with other sticky minerals and organic matter.
Recent research has shown that rivers transport microplastics to the ocean too, and laboratory experiments revealed that giant underwater avalanches of sediment can transport these tiny particles along deep-sea canyons to greater depths.
We’ve now discovered how a global network of deep-sea currents transports microplastics, creating plastic hotspots within vast sediment drifts. By catching a ride on these currents, microplastics may be accumulating where deep-sea life is abundant.
From bedroom floors to the seafloor
We surveyed an area of the Mediterranean off the western coast of Italy, known as the Tyrrhenian Sea, and studied the bottom currents that flow near the seafloor. These currents are driven by differences in water salinity and temperature as part of a system of ocean circulation that spans the globe.
Seafloor drifts of sediment can be many kilometres across and hundreds of metres high, forming where these currents lose their strength.
We analysed sediment samples from the seafloor taken at depths of several hundred metres. To avoid disturbing the surface layer of sediment, we used samples taken with box-cores, which are like big cookie cutters.
In the laboratory, we separated microplastics from the sediment and counted them under microscopes, analysing them using infra-red spectroscopy to find out what kinds of plastic polymer types were there.
Most microplastics found on the seafloor are fibres from clothes and textiles. These are particularly insidious, as they can be eaten and absorbed by organisms. Although microplastics on their own are often non-toxic, studies show the build-up of toxins on their surfaces can harm organisms if ingested.
These deep ocean currents also carry oxygenated water and nutrients, meaning that the seafloor hotspots where microplastics accumulate may also be home to important ecosystems such as deep-sea coral reefs that have evolved to depend on these flows, but are now receiving huge quantities of microplastics instead.
What was once a hidden problem has now been uncovered – natural currents and the flow of plastic waste into the ocean are turning parts of the seafloor into repositories for microplastics.
The cheap plastic goods we take for granted eventually end up somewhere. The clothes that may only last weeks in your wardrobe linger for decades to centuries on the seafloor, potentially harming the unique and poorly understood creatures that live there.
Astronauts ring opening bell for Nasdaq from space station – Thompson Citizen
CAPE CANAVERAL, Fla. — The astronauts launched into orbit by SpaceX joined in the ringing of the opening bell for the Nasdaq on Tuesday to mark “a pivotal moment” for the space economy.
NASA astronauts Doug Hurley and Bob Behnken took part in the ceremony from the International Space Station, three days after their launch by Elon Musk’s company.
SpaceX became the first private company to send astronauts into orbit, with its Falcon 9 rocket and Dragon capsule, and ended a nine-year launch drought for NASA.
The two astronauts floated alongside space station commander Chris Cassidy as he rang a ship’s bell to open trading on the Nasdaq Stock Exchange. Their image, along with live-streamed pictures of other NASA staff, lit up the Nasdaq marquee in New York’s Times Square.
“It is truly a pivotal moment in the development of the space economy and a new era of private human spaceflight,” said Nasdaq President Adena Friedman.
She asked the astronauts about making spaceflight more accessible to ordinary people.
“It’s really transformational when you come into space and look back at our planet, and then see how fragile it is and how thin the atmosphere is. It really does change you for the better,” Hurley said. “I think the more people that we expose to this, the better off we’ll be as a species.”
NASA wants to be just one customer of many, noted Jim Morhard, the space agency’s deputy administrator, who took part in the virtual bell ringing. SpaceX, Jeff Bezos’ Blue Origin, Richard Branson’s Virgin Galactic, Boeing and other companies looking to send people into space are driving down costs while increasing innovation, he said.
“We’re really at the dawn of a new space age,” Morhard said.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.
NASA astronauts describe 'smooth' ISS docking after SpaceX launch – The Globe and Mail
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Astronauts describe ride to space aboard SpaceX Crew Dragon – CBS News
Thethat boosted astronauts Douglas Hurley and Robert Behnken into space provided a slightly rougher ride than expected during the later stages of the climb to orbit, but both said Monday they enjoyed their historic trip and marveled at a sooth-as-silk .
And yes, the Crew Dragon brought a “new car smell” to the lab complex.
“It absolutely did,” said station commander Chris Cassidy, the lone American aboard the station until Hurley and Behnken arrived Sunday. “Then when we got that hatch open, you could tell it was a brand new vehicle, with smiley faces on the other side, smiley face on mine, just as if you had bought a new car, the same kind of reaction.
“Wonderful to see my friends, and wonderful to see a brand new vehicle,” he said.
from pad 39A at the Kennedy Space Center Saturday afternoon, strapped into a Crew Dragon capsule atop a Falcon 9 rocket.
It was the first piloted launch to orbit from U.S. soil in nearly nine years, the first flight of a SpaceX rocket carrying astronauts and the first new crewed spacecraft to fly in space since the first shuttle mission 39 years ago.
Both Hurley and Behnken are space shuttle veterans, familiar with the initially rough ride when the orbiter’s powerful solid-propellant boosters were firing and the transition to a much smoother experience after the boosters were jettisoned and only the ship’s liquid fueled main engines were running.
The Falcon 9 is a two-stage rocket powered by liquid oxygen and kerosene. The first stage, featuring nine Merlin engines, generates 1.7 million pounds of thrust at liftoff. The rocket’s second stage is powered by a single vacuum-rated Merlin engine.
“Shuttle had solid rocket boosters, those burned very rough for the first two-and-a-half minutes,” Hurley said. “The first stage with Falcon 9 … was a much smoother ride.”
He said the shutdown of the first stage engines, the separation of the first and second stages and then the ignition of the upper stage’s single engine was similar to the memorable launch sequence depicted in the movie “Apollo 13.”
“So the first stage engines shut off, and then it took some time between the booster separating and then the Merlin vacuum engine starting,” Hurley said. “At that point, we go from roughly three Gs (three times the normal force of gravity on the ground) to zero Gs for, I don’t know, a half a second probably, and then when that Merlin vacuum engine fires, then we start accelerating again.
“It got a little rougher with the Merlin vacuum engine, and it’ll be interesting to talk to the SpaceX folks to find out why it was a little bit rougher ride on second stage than it was for shuttle on those three main engines.”
The Crew Dragon is designed to rendezvous and dock with the space station autonomously, without any direct input from the crew. But for the first piloted test fight, Hurley took over manual control twice to verify astronauts can fly the ship on their own if necessary.
There were no problems and when the Crew Dragon docked with the station Sunday morning, Hurley and Behnken were unable to detect the impact.
“The thing that really stood out to both of us, and we mentioned it as soon as we docked, is we didn’t feel the docking,” Hurley said. “It was just so smooth.”
Hurley is a former test pilot and Behnken, who holds a doctorate in mechanical engineering from Caltech, is a veteran Air Force flight test engineer. They were selected for the first piloted Crew Dragon flight in part so they could bring those skills to evaluating the spacecraft before it begins operational missions to the space station in the late-summer timeframe.
“We’re there to evaluate how it does the mission and so far, it’s done just absolutely spectacularly,” Hurley said. “It’s a very clean vehicle. … It does everything we need it to do for this mission, so we’re very happy with that part of it.”
Including the operation of the Crew Dragon’s toilet. While he did not provide any details, Hurley said it is “very similar to the one we were used to in the space shuttle, and it worked very well. We had no issues with it.”
NASA managers have not yet decided how long Hurley and Behnken will remain in orbit. The Crew Dragon is certified for up to four months in space, but the crew could be ordered home earlier depending on how the space environment affects the capsule’s solar arrays, the weather in the Atlantic Ocean splashdown zone and other factors.
Not knowing when they might be coming home is “a little bit strange,” Behnken said. “I’m trying to explain it to my son, just six years old, and from his perspective, he’s just excited that we’re going to get a dog when I get home. And so he’s accepting that uncertainty and continuing to send messages to me while I’m on orbit.”
The mission is expected to last at least six weeks and possibly up to four months, far longer than their relatively brief shuttle flights. Staying in touch with their wives, both veteran astronauts, and their two sons is a top priority for both Hurley and Behnken.
“One of the things I was most excited about (after launch) was being able to make a phone call home,” Behnken said. “It’s been a long time since I launched into orbit, and I’ve got a little boy who got a chance to watch me do that for the first time in his life. And I just wanted to understand what his experience was and share that a little bit with him.
“He was able to make the trip back to Houston after watching the docking from down in Florida and was pretty excited about the whole thing. So that was wonderful for me.”
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