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Climate change will turn coastal Antarctica green, say scientists – Phys.org

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Dr. Matt Davey sampling snow algae at Lagoon Island, Antarctica. Credit: Sarah Vincent

Scientists have created the first ever large-scale map of microscopic algae as they bloomed across the surface of snow along the Antarctic Peninsula coast. Results indicate that this ‘green snow’ is likely to spread as global temperatures increase.

The team, involving researchers from the University of Cambridge and the British Antarctic Survey, combined with on-the-ground observations over two summers in Antarctica to detect and measure the green . Although each individual alga is microscopic in size, when they grow en masse they turn the bright green and can be seen from space. The study is published today in the journal Nature Communications.

“This is a significant advance in our understanding of land-based life on Antarctica, and how it might change in the coming years as the climate warms,” said Dr. Matt Davey in the University of Cambridge’s Department of Plant Sciences, who led the study. “Snow are a key component of the continent’s ability to capture from the atmosphere through photosynthesis.”

Blooms of green snow algae are found around the Antarctic coastline, particularly on islands along the west coast of the Antarctic Peninsula. They grow in ‘warmer’ areas, where average temperatures are just above zero degrees Celsius during the austral summer—the Southern Hemisphere’s summer months of November to February. The Peninsula is the part of Antarctica that experienced the most rapid warming in the latter part of the last century.

The team found that the distribution of green snow algae is also strongly influenced by marine birds and mammals, whose excrement acts as a highly nutritious natural fertiliser to accelerate algal growth. Over 60% of blooms were found within five kilometres of a penguin colony. Algae were also observed growing near the nesting sites of other birds, including skuas, and areas where seals come ashore.

The team used images from the European Space Agency’s Sentinel 2 satellite taken between 2017 and 2019, and combined these with measurements they made on the ground in Antarctica at Ryder Bay, Adelaide Island, and the Fildes Peninsula, King George Island.

“We identified 1679 separate blooms of green algae on the snow surface, which together covered an area of 1.9 km2, equating to a carbon sink of around 479 tonnes per year” said Davey. Put into context this is the same amount of carbon emitted by about 875,000 average petrol car journeys in the UK.

Almost two thirds of the green algal blooms were on small, low-lying islands with no high ground. As the Antarctic Peninsula warms due to rising global temperatures, these islands may lose their summer snow cover and with it their snow algae. However, in terms of mass, the majority of snow algae is found in a small number of larger blooms in the north of the Peninsula and the South Shetland Islands, in areas where they can spread to higher ground as low-lying snow melts.

“As Antarctica warms, we predict the overall mass of snow algae will increase, as the spread to higher ground will significantly outweigh the loss of small island patches of algae,” said Dr. Andrew Gray, lead author of the paper, and a researcher at the University of Cambridge and NERC Field Spectroscopy Facility, Edinburgh.

Photosynthesis is the process in which plants and algae generate their own energy, using sunlight to capture carbon dioxide from the atmosphere and release oxygen. There are many different types of algae, from the tiny, single-celled species measured in this study, to large leafy species like giant kelp. The majority of algae live in watery environments, and when excess nitrogen and phosphorous are available they can multiply rapidly to create visible algal blooms.

The researchers say that the total amount of carbon held in Antarctic snow algae is likely to be much larger because carbon dioxide is also taken up by other red and orange algae, which could not be measured in this study. They plan further work to measure these other algal blooms, and also to measure the blooms across the whole of Antarctica using a mixture of field work and satellite images.

Antarctica is the world’s southernmost continent, typically known as a frozen land of snow and ice. But terrestrial life can be abundant, particularly along its coastline, and is responding rapidly to climate changes in the region. Mosses and lichens form the two biggest visible groups of photosynthesising organisms, and have been the most studied to date. This new study has found that microscopic algae also play an important role in Antarctica’s ecosystem and its carbon cycling.


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Image: Baltic blooms


More information:
Nature Communications (2020). DOI: 10.1038/s41467-020-16018-w

Citation:
Climate change will turn coastal Antarctica green, say scientists (2020, May 20)
retrieved 20 May 2020
from https://phys.org/news/2020-05-climate-coastal-antarctica-green-scientists.html

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What a dinosaur's last supper reveals about life in the Cretaceous period – CBC.ca

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A beautifully preserved armoured dinosaur found in an Alberta oilsands mine died on a full stomach. The “extraordinarily rare” preservation of its last meal offers new clues and surprises about how the dinosaur lived during its last days.

The 5.5-metre-long, 1,300 kilogram spiky, plant-eating nodosaur, similar to an ankylosaurus but without a tail club, is the only known one of its species, Borealopelta markmitchelli. (Its name means “shield of the north” and honours Mark Mitchell, the technician who spent 7,000 carefully extracting the fossil from the surrounding rock). 

Victoria Arbour, an evolutionary paleontologist at the Royal BC Museum, describes how some armoured dinosaurs likely used their horns, spines and armour for fighting each other, not just for protection. 1:34

The nodosaur lived 110 million years ago during the early Cretaceous, in a lush forest of conifers, ferns and palm-like plants called cycads, near the coast of what was then an inland sea. At the time, the climate was warmer, similar to that of South Carolina, said Caleb Brown, a paleontologist at the Royal Tyrrell Museum of Paleontology in Alberta and lead author of the new study. It was published this week in the journal Royal Society Open Science.

The fossil was discovered by accident in 2011 by Shawn Funk, a shovel operator at the Suncor Millennium Mine near Fort McMurray. Paleontologists from the Royal Tyrrell were called to have a look and realized at once that it was no ordinary fossil.

While most fossils include only bones, this one included skin. It was so well-preserved that it has been described as “mummified.”

Meet one of the world’s best-preserved dinosaurs ever. Borealopelta fossilized so perfectly that we can see every inch of its armour and skin in 3D, 110 million years after its death. 0:58

In the dinosaur’s belly, “there were these massive concentrations of what looked like rocks,” Brown said.

Those were in a mass about the size of a soccer ball, and it appears they were gastroliths — rocks that some plant-eating dinosaurs use to grind up their food in their stomachs, as modern birds do, instead of using their teeth.

Sure enough, when chunks of the mass were encased in resin, sliced and examined under the microscope, the researcher could see well-preserved twigs, leaves, mosses, pollen and spores.

To get some help at identifying the plant material, the dinosaur researchers turned to paleobotanists, including University of Brandon researcher David Greenwood and his team, along with their retired Royal Tyrrell colleague Dennis Braman.

Inside the nodosaur’s belly was a mass about the size of a soccer ball that contained rocks. The rocks are called gastroliths and are used to grind up the animal’s food within its stomach. (Royal Tyrrell Museum)

Ferns and charcoal

They discovered that the dinosaur was a bit of a picky eater. While it lumbered through a landscape that was lush with conifers, horsetails and cycads, there weren’t a lot of those in its stomach.

“It’s almost all ferns,” Brown said, noting that ferns aren’t actually very nutritious. “It wasn’t just hoovering up everything on the landscape.”

But to him, the biggest surprise was that the stomach also contained a significant amount of wood, mostly charcoal, suggesting it was feeding in an area that had recently been ravaged by wildfires.

“And that’s a really cool result,” Brown said. “Because if you look at large mammals that are herbivores today, they often seek out areas that are recovering from forest fires.”

That’s because the new growth tends to be lush, more nutritious than older plants, and low to the ground where it’s easily accessible.

Microscope images show some of the plant material found inside the stomach, including a club moss spore sac (a), fern spore sacs (b-d), a charcoal fragment (e), parts of plant stems and leaves (f-l) and a cross section of a twig, showing its annual rings (m). (Brown et al/Royal Tyrrell Museum)

Forensic paleobotany

By looking at the types of spores and the fact that the twigs appeared to be in the middle of their growing season, the researchers figured out that the animal died during the wet season, which was late spring or early summer.

In Dinosaur Cold Case, a recent documentary about the fossil on CBC’s Nature of Things, Greenwood said extreme storms and flash floods would have been a problem at that time of year on the coastal plain where the dinosaur and suggested that being swept away by rushing water may have been what caused its death.

These are some plant fossils from Alberta from about the time that Borealopelta lived, including ferns, a gingko (d), horsetails (i) and a conifer cone (j). (Brown et al/Royal Tyrrell Museum)

The discoveries about the nodosaur’s last meal are significant because to date, Brown said, “we know almost nothing about what herbivorous dinosaurs eat.”

Only guesses can be made based on what plants lived nearby and the dinosaur’s teeth. There are also clues in fossil dinosaur feces, but the plant material in those are often digested beyond recognition and it’s difficult to know which dinosaur they came from.

Part of the problem is that finding preserved stomach contents from a dinosaur is “extraordinarily rare,” Jim Basinger of the University of Saskatchewan, a co-author of the study, said in a statement. 

Nine cases of possible dinosaur stomachs of plant-eating dinosaurs have been found, the researchers note, but most have turned out to just be plant material found nearby rather than actual stomachs. In this case, the dinosaur was washed far out to sea, without any plants from the landscape it lived in, before it was fossilized.

“So in this case we have what I would say is by far the best evidence that these are stomach contents,” Brown said.

That said, he notes that it may not necessarily be representative of what this species normally ate, as an animal’s diet can vary depending on its age, its health, and the seasonal availability of different foods.

Still, he said it’s useful to be able to compare it to what scientists think plant-eating dinosaurs were eating at that time and raises new questions to investigate, such as: How much of this food a dinosaur this size would have needed to eat to sustain itself? And how did it digest it?

 “I think give us a benchmark for figuring out how this animal may have lived.”

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‘Strawberry Moon’ to rise with a special eclipse for some skywatchers – Globalnews.ca

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The full moon on Friday, June 5 might look a little different in some parts of the world, where the so-called “Strawberry Moon” will fall partially under the Earth’s shadow.

The phenomenon, known as a penumbral lunar eclipse, occurs when the Earth comes between the sun and the moon, thereby casting a faint shadow on the moon. This penumbral lunar eclipse will make the full moon look slightly darker on part of its surface, although only some portions of the world will see it.

The penumbral lunar eclipse will only be visible from parts of Australia, Asia, Africa, Europe and South America, according to NASA’s charts.


READ MORE:
Pentagon officially releases three leaked ‘UFO’ videos

In other words, North Americans will need to watch a livestream on the internet to catch a glimpse of the event, which starts at 3 p.m. EDT. Nevertheless, the so-called “Strawberry Moon” will be visible to everyone.

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That name comes from the time of year and not the expected colour of the moon. There are farm-related nicknames for the first full moon of every month, and the strawberry nickname originated from the Algonquin First Nation, according to the Old Farmer’s Almanac. The first full moon of June often coincided with the harvest season for wild strawberries in North America, the Almanac says.


The Strawberry Moon is practically full over the horizon as a lady poses for a photo in Malaga, Spain, on June 4, 2020.


Jesus Merida/SOPA Images/LightRocket via Getty Images

Although skywatchers in Canada and the U.S. will miss out on this penumbral lunar eclipse, they’ll only have to wait a month to catch the next one. Another penumbral lunar eclipse is slated to happen on July 5, and that one should be visible from North America. The darkest penumbral lunar eclipse of the year is expected on Nov. 30.

A penumbral lunar eclipse also happened on Jan. 10, coinciding with that month’s “Wolf Moon.”

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0:59
Timelapse captures moment sky darkens for total solar eclipse


Timelapse captures moment sky darkens for total solar eclipse

Not to throw shade at the penumbral lunar eclipses, but they’ll likely pale in comparison to the annular solar eclipse predicted for June 21. That’s when the moon will pass between the Earth and the sun, making the sun look like a ring of fire for viewers in parts of Africa, China, northern India and Pakistan, according to TimeandDate.com.

Again, it won’t be visible from North America — but you’ll still be able to watch the whole thing online without risking eye damage from staring at the sun.

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© 2020 Global News, a division of Corus Entertainment Inc.

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In Space No One Can Hear You Campaign: Trump Team Pulls Ad – NDTV

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Donald Trump’s re-election campaign has pulled a video featuring the SpaceX launch and astronauts

Washington:

President Donald Trump’s re-election campaign has pulled a video featuring the SpaceX launch and astronauts which appeared to violate NASA’s media regulations, reports said.

The “Make Space Great Again” YouTube ad posted on YouTube showed footage from the Apollo program, as well as video of the landmark SpaceX Demo-2 mission and NASA astronauts Bob Behnken and Doug Hurley, the SpaceNews.com website said.

YouTube shows the video was removed by the uploader.

NASA generally allows use of its images and video but prohibits the use of its insignia and photographs of its astronauts in advertisements.

“As a government agency, NASA will not promote or endorse or appear to promote or endorse a commercial product, service or activity. Therefore, there are strict limits placed on the use of any of the NASA identities and emblem imagery in advertisements,” the space agency’s advertising regulations say.

“Astronauts or employees who are currently employed by NASA cannot have their names, likenesses or other personality traits displayed in any advertisements or marketing material.”

Hurley’s wife Karen Nyberg, a retired astronaut, and their young son were also reportedly shown in the clip.

“I find it disturbing that a video image of me and my son is being used in political propaganda without my knowledge or consent. That is wrong,” Nyberg tweeted.

A Change.org petition to “Stop Donald Trump politicizing SpaceX and NASA accomplishments” has attracted more than 6,000 signatures so far.

The New York Times described the video as “the latest effort by the president to parlay his stewardship of American space policy into an upbeat campaign issue.”

The SpaceX mission, which blasted off from Florida’s Kennedy Space Center on May 30, was the first crewed US spacecraft in nearly a decade.

Trump, who witnessed the liftoff, has relaunched the race to re-conquer the Moon and to journey onwards to the Red Planet.

But the deadlines — 2024 and 2033 respectively — appear unrealistic and have caused turbulence within the space agency.

(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)

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