adplus-dvertising
Connect with us

Science

And Then the Sea Glowed a Magnificent Milky Green – Hakai Magazine

Published

 on


Article body copy

The sky was moonless and overcast, leaving no stars to steer by. Alone at the helm in the middle of the Arabian Sea, somewhere between Oman and India, I could see nothing in the ink-black night save for our ship’s dimly lit compass rolling on its gimbal mount as we heaved and swayed through three-meter seas. But half an hour into my shift, the sails above me began to glow, as if the moon had risen. But there was no moon, nor any stars or other ships. The light, it seemed, was coming from below and growing in intensity. Soon the entire ocean was glow-stick green, but muted, as if the light were shining through a sea of milk.

It was August 2010, and I’d been sailing for over two months by then, volunteering with the NGO the Biosphere Foundation to deliver the Mir, a 35-meter ketch they’d recently acquired in Malta, back to their home port in Singapore. During the voyage, I’d grown accustomed to the usual “sea sparkle” caused by dinoflagellates that ignite when the water is agitated, causing ribbons of light to twist off the Mir’s bow. But this was not that. This was the whole of the ocean, as far as I could see, glowing a uniform, opaque green. Despite the compass still wheeling in its mount, the light in the water created an optical illusion, making the sea appear perfectly calm, as if we were gliding through phosphorescent skies rather than roiling seas.

I woke the rest of the crew, and for over four hours we remained engulfed in this sea of green light, wonderstruck, with no idea what it was we were witnessing. Finally, a razor-sharp line appeared ahead of us where the lambent sea ended and blackness began. Crossing it, we left behind that numinous phantom world and re-entered a familiar one, though we could still see the gauzy green glow to our stern for another hour before it disappeared. It wasn’t until we arrived at port 10 days later that we would learn the name for the eerie phenomenon that had surrounded us: a milky sea.

In August 2010, author Sam Keck Scott and his crewmates were sailing in the Arabian Sea when they became some of the few people to witness a milky sea. Photo courtesy of Biosphere Foundation


For centuries, sailors have been describing milky seas, rare occurrences where enormous expanses of the ocean light up uniformly at night, at times stretching for tens of thousands of square kilometers, or more. W. E. Kingman, captain of the clipper Shooting Star, had this to say upon witnessing one in 1854: “The scene was one of awful grandeur; the sea having turned to phosphorus, and the heavens being hung in blackness, and the stars going out, seemed to indicate that all nature was preparing for that last grand conflagration which we are taught to believe is to annihilate this material world.”

A milky sea even made an appearance in Moby-Dick, where Melville describes a mariner sailing through a “shrouded phantom of the whitened waters” that were as “horrible to him as a real ghost.”

Neither our small crew, nor Melville or Kingman, knew what caused the seas to glow. In 2010, our crew had the benefit of living in a world far better charted by science than it had been in the 1800s, which may explain why Kingman and Melville’s mariner responded with god-struck terror, while we gawked in wonder, knowing that no matter how otherworldly this phenomenon may appear, it was clearly of this world.

Bioluminescence—the emission of light by a living organism—is common on our planet, and nowhere more so than in the oceans. Bioluminescent fish, tunicates, dinoflagellates, crustaceans, mollusks, jellyfish, and bacteria glow and flash across our seas at night. But milky seas, despite being so vast, are anything but common, and are thought to be caused by one of the smallest organisms in the ocean.

Every observation of a milky sea throughout history has been a chance encounter, as mine was, and only once did a vessel with any scientific research capabilities happen upon one, when the USS Wilkes steamed through a milky sea for three consecutive nights off the island of Socotra, Yemen, in 1985. Onboard the Wilkes was the late marine biologist David Lapota, who was working for the navy at the time studying bioluminescence. Lapota and his team of researchers sampled the water and discovered a profusion of the bioluminescent bacterium Vibrio harveyia common, well-dispersed species known to luminesceattached to bits of algae, leading them to hypothesize that legions of this bacterium and potentially other bioluminescent bacterial species as well, are the cause of milky seas. This research, conducted nearly 40 years ago, remains the only time a milky sea was ever studied in the field.

bioluminescent glow in a flask

There are no existing photos of a milky sea in nature, but this sample of bioluminescing bacteria demonstrates the uniform glow of the phenomenon on a small scale. Photo courtesy of Steve Miller

Assuming scientists are correct that milky seas are caused by bacteria, a question remains: why? Unlike many organisms that evolved bioluminescence as a means to escape predation, bioluminescent bacteria want to be eaten—the inside of a fish’s gut provides a more reliable home than floating freely in the open ocean. But a lone bacterium is likely too small to get the attention of a fish on its own, so for their microscopic bioluminescence to express on a macroscale, they require strength in numbers. To work together, each bacterium releases a chemical signal to sense if other bacteria are nearby, and only once they’ve recognized a sufficient numberscientists hypothesize that it takes a population of somewhere between 10 and 100 million bacteria per milliliter of waterwill they begin to luminesce. This is a process called quorum sensing, and it may explain why milky seas form.

In areas of upwelling, such as the northwest Indian Ocean, where an abundance of nutrient-rich, decaying organic material—such as bits of decomposed crabs or even specks of long-dead whales—is pushed up to the surface from the depths, bacteria will find plenty to colonize. When these rich waters become isolated due to currents, or when distinct masses of water with differing salinities or temperatures meet and form physical fronts, they can prevent mixing, which in turn can result in a sort of concentrated stew—what scientists have dubbed “the natural flask hypothesis.” In this scenario, through quorum sensing, these bacteria set off a chemical glow that can become the largest display of bioluminescence on the planet.

This idea of a natural flask may help to explain why, when our boat first sailed into a milky sea, the light was diluted and nearly imperceptible, but when we exited it hours later, we crossed a distinct boundary. On one side of that particular event, the glowing and non-glowing waters were mixing, while on the other side, due to some sort of oceanic front, a wall-like barrier was being maintained between the specialized—and little understood—conditions that allow milky seas to form and those conditions that do not. This is but one of many things scientists hope to better understand by further studying milky seas in the field, which, thanks to a new generation of satellite technology, may soon be possible.

Steve Miller, director of the Cooperative Institute for Research in the Atmosphere, has been part of a small group of scientists leading the effort to demystify milky seas for nearly 20 years, searching for them from the unlikeliest of places: Fort Collins, Colorado. He’s the first person to discover a milky sea from his office chair.

Miller contacted me shortly after I wrote a blog post about our experience sailing through a milky sea, excitedly informing me that our ship’s crew are among the few known people alive today to have ever witnessed one. Our brief correspondence left me feeling like a minor celebrity.

Miller first became interested in milky seas in 2004 while attending an American Meteorological Society conference. There, Miller and his colleagues considered whether it might be possible to observe any type of marine bioluminescence from space. It was assumed that any small-scale bioluminescence, such as sea sparkle, produces far too weak a light signal to be seen from so far away. But Miller, intrigued by the idea of studying the sea from space, did some research when he returned home and was struck to discover dozens of surprisingly consistent accounts of so-called milky seas given by mariners throughout the centuries. An atmospheric scientist by training, Miller wondered if he could use historical satellite data to locate one of these events. It didn’t take long to find what he was looking for: a detailed account of a milky sea seen by the crew of the SS Lima off the coast of Somalia on January 25, 1995. The account listed the exact coordinates and time when the boat had entered the luminous event. Using the heading and speed from the ship’s log, Miller was able to extrapolate the position of the Lima at the time the crew claimed to have exited the glowing waters six hours later. He plotted the points, the date, and the times on the image, and zoomed in on the grainy black-and-white photo. “It was all black,” he tells me.

Undeterred, Miller decided to scale the image down some more, searching through the noise of a photograph taken from over 800 kilometers away. Suddenly, a small structure appeared in the center of his computer screen that he at first mistook for a fingerprint smudge, but when he moved the image around, the smudge moved along with it. He zoomed in some more and a comma shape appeared in the waters off the Horn of Africa. When he once again overlaid the ship’s coordinates, they lined right up with the comma’s boundaries. “That’s when we realized we had something,” he says. The shape, larger than the state of Connecticut, was over 15,000 square kilometers of glowing bacteria.

“I’ve been hooked on that ever since,” says Miller, “because I realized I’d just seen a ghost.” Milky seas were more a part of novels and folklore than of scientific knowledge, he explains, but here they had the first-ever space-borne confirmation of a milky sea.

Since that initial discovery, a new generation of satellite technology has greatly improved Miller’s hunt for milky seas. Two satellites operated by the National Oceanic and Atmospheric Administration—the Suomi National Polar-orbiting Partnership and the Joint Polar Satellite System—were launched in 2011 and 2017, respectively. These modern satellites, though not intended to search for milky seas, are equipped with specialized day/night band instruments that, at their extreme low end of sensitivity, can pick up something as dim as bioluminescence from space. Miller and his team have been combing through the imagery provided by these satellites ever since, having greatest success in the two areas of the globe where historical ship sightings of milky seas have been most prevalent: the northwest Indian Ocean, where 70 percent of all milky seas have been reported, and the waters surrounding Java, where 17 percent of sightings have occurred. In the past decade, Miller and his team have successfully identified a dozen milky seas via satellite imagery, the most significant of which was a 2019 event off the coast of Java spanning over 100,000 square kilometers—roughly the size of Iceland—which glowed continuously for at least 45 nights.

satellite images of milky seas off Java

Steve Miller, director of the Cooperative Institute for Research in the Atmosphere, and his colleagues have identified the location of several milky seas by using satellite images acquired with the use of specialized day/night band instruments that can perceive bioluminescence from space. Photo courtesy of Steve Miller

Now that Miller and his team have confirmed that milky seas can last for weeks at a time, it opens up the possibility of deploying a research vessel to study one while it’s still glowing. Only then do they hope to be able to answer some of the many questions scientists still have about milky seas, including one of Miller’s favorites: how deep does the bioluminescence go down in the water column? Is it merely a surface slick of bacteria, as some scientists posit, or is it meters thick, or more? Considering scientists believe it takes upward of 100 million bacteria per cubic centimeter of water to begin glowing, the answer to this question could change the estimated number of bacteria involved in a milky sea by billions of trillions, or possibly even trillions of trillions.

When I first learned of Miller’s breakthrough research, part of me felt protective of the mystique of milky seas. Why must we humans insist on explaining everything? But as I learned more about what scientists believe might cause milky seas—about upwelling and natural flasks; about quorum sensing and the intentional, communal light made by trillions of bacteria—I realized that finding answers doesn’t necessarily correlate with diluting the wonder of such an event. If anything, it makes it that much more incredible.

Without understanding the world around us, we are all Captain Kingman, terrified by the sight of something we don’t recognize. Instead, we can be in awe of reality itself, knowing that whenever one question is answered, we’ve simply learned enough to ask a thousand more.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

News

Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

Published

 on

 

More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

___

Follow AP’s climate coverage at https://apnews.com/hub/climate

___

Follow Seth Borenstein on Twitter at @borenbears

___

Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

Source link

Continue Reading

Science

‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

Published

 on

 

It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

Source link

Continue Reading

News

The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

Published

 on

 

TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

Source link

Continue Reading

Trending