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Qatar- Shrinking glaciers: New study reveals point of no return – MENAFN.COM

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(MENAFN – Gulf Times) Shrinking glaciers in Greenland have been a worsening problem for the entire planet. A latest study has just revealed that the situation has sadly crossed a point of no return. Nearly four decades of satellite data from Greenland shows that glaciers on the island have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking.
The finding, published on August 13, in the journal Nature Communications Earth and Environment, means that Greenland’s glaciers have passed a tipping point of sorts, where the snowfall that replenishes the ice sheet each year cannot keep up with the ice that is flowing into the ocean from glaciers. The alarming information is contained in a report released by The Ohio State University.
It may be noted that the ice that melts or breaks off from Greenland’s ice sheets ends up in the Atlantic Ocean and, eventually, all of the world’s oceans. Ice from Greenland is a leading contributor to sea level rise last year, enough ice melted or broke off from the Greenland ice sheet to cause the oceans to rise by 2.2mm in just two months. Explaining the new finding, Michalea King, lead author of the study and a researcher at The Ohio State University’s Byrd Polar and Climate Research Center, said that the ice that is discharging into the ocean is far surpassing the snow that is accumulating on the surface of the ice sheet. The study depended on remote sensing observations on how ice discharge and accumulation have varied.
King and other researchers analysed monthly satellite data from more than 200 large glaciers draining into the ocean around Greenland. Their observations show how much ice breaks off into icebergs or melts from the glaciers into the ocean. They also show the amount of snowfall each year the way these glaciers get replenished. The researchers found that, throughout the 1980s and 90s, snow gained through accumulation and ice melted or calved from glaciers were mostly in balance, keeping the ice sheet intact. Through those decades the ice sheets generally lost about 450 gigatonnes (about 450bn tonnes) of ice each year from flowing outlet glaciers, which was replaced with snowfall.
The researchers measured the pulse of the ice sheet how much ice glaciers drain at the edges of the ice sheet which increases in the summer. They saw it was relatively steady until a big increase in ice discharging to the ocean during a short five- to six-year period. Their analysis found that the baseline of that pulse the amount of ice being lost each year started increasing steadily around 2000, so that the glaciers were losing about 500 gigatonnes each year. Snowfall did not increase at the same time, and over the last decade, the rate of ice loss from glaciers has stayed about the same meaning the ice sheet has been losing ice more rapidly than it’s being replenished. Before 2000, the ice sheet would have about the same chance to gain or lose mass each year. In the current climate, the ice sheet will gain mass in only one out of every 100 years.
King said that large glaciers across Greenland have retreated about 3km on average since 1985, which is a lot of distance. The glaciers have shrunk back enough that many of them are sitting in deeper water, meaning more ice is in contact with water. Warm ocean water melts glacier ice, and also makes it difficult for the glaciers to grow back to their previous positions. Yes, there is no going back now. What about adaptation and mitigation remains to be seen.

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Newly-discovered asteroid buzzes past Earth Thursday morning – The Weather Network

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Astronomers are tracking a newfound asteroid that is expected to make a brief but very close pass by Earth, early Thursday morning.

Asteroid 2020 SW was discovered on September 18, by the Catalina Sky Survey in Arizona. Estimated at between 5 to 10 metres wide, this space rock will make its closest pass by Earth at 7:12 a.m. EDT, on Thursday, September 24.

At that time, it is expected to be roughly 22,000 kilometres above the planet’s surface.

“There are a large number of tiny asteroids like this one, and several of them approach our planet as close as this several times every year,” Paul Chodas, director of the Center for Near-Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory, said in a press release on Wednesday. “In fact, asteroids of this size impact our atmosphere at an average rate of about once every year or two.”

This frame from the NASA asteroid trajectory animation shows 2020 SW at its closest approach to Earth. Credit: NASA JPL

At that distance, the asteroid is actually closer than the ring of geostationary weather and communications satellites surrounding Earth at a distance of around 36,000 kilometres. However, as the image above shows, by then, the asteroid will be below the satellite ring and beneath Earth.

Although 2020 SW is logged as a “potentially hazardous asteroid” in NASA’s records, it doesn’t pose any threat to Earth. According to CNEOS, who has traced the asteroid’s orbit back to 1975 and forward to 2095, this September 24 pass is the closest this object has ever come to us in that timespan.

Asteroid-2020SW-Orbit-NASA-CNEOSThe shape of asteroid 2020 SW’s 373-day orbit around the Sun marks it as an Apollo asteroid – an Earth-crossing asteroid that spends all of its time between the orbits of Venus and Mars. Credit: NASA CNEOS

The next time the asteroid will be anywhere close to Earth again is in September of 2041. At that time, it will be pass far beyond the Moon, at a distance of over 3.5 million kilometres.

While 2020 SW poses no threat to Earth, it is still of interest to scientists. NASA’s Goldstone Observatory is planning to bounce radio waves off the asteroid’s surface during this close pass. The data collected can then be turned into radar images, revealing the asteroid’s shape and giving us an idea of its composition.

Goldstone-Observatory-NASAThe 34-meter DSS-13 radio antenna at the Goldstone Observatory is used for radio astronomy, including collecting radar images of passing near-Earth objects. Credit: NASA

According to NASA, if 2020 SW or an asteroid of similar size did actually strike Earth, it would almost certainly break apart high up in the atmosphere as a fireball. Only the toughest space rocks of this size – those primarily composed of metal – can reach the surface mostly intact.

“The detection capabilities of NASA’s asteroid surveys are continually improving,” added Chodas, “and we should now expect to find asteroids of this size a couple days before they come near our planet.”

Indeed, the fact that this tiny rock was spotted roughly six days before its flyby is a testament to the Catalina Sky Survey’s asteroid detection skills.

Sources: NASA JPL | NASA CNEOS

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Reptile dubbed 'Jaws of Death' terrorized Cretaceous seas – CANOE

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“If you were an animal in the oceans less than 20 feet (6 metres) in length, you are most likely on the menu for Gnathomortis,” added Lively, whose study was published in the Journal of Vertebrate Paleontology.

That menu, Lively said, may have included sea turtles, fish, sharks and other marine reptiles including smaller mosasaurs.

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Like other mosasaurs and many lizards and snakes, it boasted an extra set of teeth on the roof of its mouth.

A large depression on the outer surface of its lower jaws is indicative of large muscles that gave it tremendous bite-force. While it lived alongside even-larger mosasaurs like 46-foot-long (14-metre-long) Tylosaurus in the Western Interior Seaway that ran from present-day Canada to Mexico, Gnathomortis had stronger jaws.

“‘Jaws of Death’ seemed appropriate for this kind of critter,” Lively said, “and it turns out to be an awesome name.”

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Bus-size asteroid to zoom by Earth, ducking below satellites – CTV News

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CAPE CANAVERAL, FLA. —
An asteroid the size of a school bus is headed our way, but NASA says the space rock will zoom safely past Earth on Thursday.

The newly discovered asteroid will come within 13,000 miles (22,000 kilometres) of Earth, well below many of the communications satellites orbiting the planet, scientists said this week. The closest approach will occur Thursday morning over the southeastern Pacific Ocean.

Once it’s gone, the asteroid won’t be back to Earth’s neighbourhood until 2041.

Scientists estimate the asteroid is between 15 feet and 30 feet (4.5 metres to 9 metres). By asteroid standards, that’s considered puny. Asteroids of this size hit Earth’s atmosphere and burn up once every year or two, said Paul Chodas, director of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory. There could be as many as 100 million of these little asteroids out there.

The real threat are considerably bigger asteroids. The good news is that these are easier to spot much sooner than just a few days out.

Asteroid 2020 SW, as it is known, was discovered last Friday by the Catalina Sky Survey at the University of Arizona in Tucson.

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.

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