In a recent research, a team of scientists have published that Antarctica is experiencing a sudden increase in ice loss which is causing small changes in the gravitational field of the Earth. Since 2009, multiple glaciers along a vast coastal expanse have disappeared in the ocean.
“To date, the glaciers added roughly 300 cubic km of water to the ocean. That’s the equivalent of the volume of nearly 350,000 Empire State buildings combined,” a lead study author Bert Wouters at the University of Bristol said.
“The fact that so many glaciers in such a large region suddenly started to lose ice came as a surprise to us. It shows a very fast response of the ice sheet: in just a few years the dynamic regime completely shifted”, added Bert.
The changes were detected by the CryoSat-2 satellite, operated by the European Space Agency.
The ice loss in the region is so large that it is causing small changes in the gravity field of the Earth. Such a change can be detected by another satellite mission, the Gravity Recovery and Climate Experiment (GRACE).
In the last two decades, the ice shelves in the region have lost almost one-fifth of their thickness, thereby reducing the resisting force on the glaciers.
“To pinpoint the cause of the changes, more data need to be collected. A detailed knowledge of the geometry of the local ice shelves, the ocean floor topography, ice sheet thickness and glacier flow speeds are crucial to tell how much longer the thinning will continue,” Wouters concluded.
There was a time — in this northwest corner of Montana — when glaciers ruled the land.
Crown of the Continent
The abundance of the massive rivers of ice — and their runoff — created “a land of striking scenery.” That’s how American anthropologist, historian, naturalist and writer George Bird Grinnell described Glacier National Park, nine years before the land was set aside as a national park on May 11, 1910.
Today, there are far fewer icy behemoths. And they’re all shrinking.
“There are currently 26 glaciers in Glacier National Park,” says national parks traveler Mikah Meyer. “I can’t remember the exact number that there were when it was founded but it was vastly higher,” he added. “The glaciers are melting and the snowfall is not restoring their size in the way that they have in past years.”
But the glaciers – both those long gone and those that still remain — have left their mark. As they started melting 10,000 years ago, they carved out majestic mountains, lush valleys, and pristine lakes.
Glacial waters are the headwaters for streams that flow west to the Pacific Ocean, south to the Gulf of Mexico, and east across the continent to Hudson’s Bay, according to the National Park Service. It emphasizes that that runoff “affects waters in a huge section of North America.”
With more than 760 lakes and nearly half a million hectares of parkland, it’s easy to see why Mikah has returned.
“Five years ago I stood on this exact same spot; at the end of the dock on Lake McDonald in Glacier National Park,” he said as he stood in front of a landscape so serene, it could have passed as a painting.
“It was one of my first experiences with the National Park Service site and I was hooked,” he admitted.
Waters from those melting glaciers also feed Iceberg Lake — another popular attraction in the park. “It is very cold and very windy and lots of little icebergs floating back there by the snow,” Mikah said as he braved the winds to capture the scene with his camera.
But despite the cold, nearby wildflowers were in full bloom, creating a pastoral setting. As Mikah walked through a field of bear grass, he said he felt like he was “in some fairytale land.”
The elegant white blossoms are a common wildflower in Glacier National Park, which this year grew in prolific numbers. They provided a perfect environment to view the local wildlife, including deer, moose, marmots and mountain goats.
Generous tour companies
Mikah got lucky when several tour companies offered him a chance to explore the park from a variety of perspectives. With Red Bus Tours, Mikah got a nice overview of the park from their vintage 1930s buses.
“It’s a massive park — it takes an hour and a half just to cross it,” he noted. “So it’s a guided tour that allows you to focus on looking at the beauty of the park instead of having to stay on these tiny mountain roads.”
Swan Mountain Outfitters donated a horseback tour for an eight-hour trek to Cracker Lake, an eye-popping turquoise body of water which is also fed by melting glacial waters.
Mikah described the scene: “You crest over this hill on the horses and you’re in the middle, surrounded by bear grass and trees and flowers and these large gray mountains in the background, and it just pops like nothing else.”
And thanks to Montana Whitewater Rafting, Mikah got to experience those glacial waters up close during a rafting tour on the Middle Fork River — a 150-kilometer river in western Montana that forms the southwestern boundary of the park.
“It was a very clear river,” Mikah said, since the water was a combination of glacier melt and snow runoff. “So you could see down through the water to the bottom, see the rocks, and the fish, so very pure, very clear water.”
Mikah was pleased to have experienced the park from the depths of the water as well as from the top of a ski lift where he could see “where it all started.”
Mikah, who’s on a mission to visit all 417 national parks in the U.S., says he hopes to come back again one day, even if the glaciers are gone.
“Even if the physical glaciers don’t still exist because they melted away, it can still be Glacier National Park because that’s what created this amazing landscape.” (VOA)
NASA plans on getting Martian samples to Earth from Mars
To know if life existed anywhere other than on Earth
Washington, Dec 11: (IANS) NASA has revealed how it plans to bring back Martian samples to Earth for the first time with the help of its next rover mission to the Red Planet, Mars 2020.
After landing on Mars, a drill will capture rock cores, while a caching system with a miniature robotic arm will seal up these samples. Then, they will be deposited on the Martian surface for possible pickup by a future mission, NASA said.
“Whether life ever existed beyond Earth is one of the grand questions humans seek to answer,” said Ken Farley of NASA’s Jet Propulsion Laboratory in Pasadena, California.
“What we learn from the samples collected during this mission has the potential to address whether we’re alone in the universe,” Farley said.
Mars 2020 relies heavily on the system designs and spare hardware previously created for Mars Science Laboratory’s Curiosity rover, which landed in 2012.
Despite its similarities to Mars Science Laboratory, the new mission has very different goals – it will seek signs of ancient life by studying the terrain that is now inhospitable, but once held flowing rivers and lakes, more than 3.5 billion years ago.
To achieve these new goals, the rover has a suite of cutting-edge science instruments.
It will seek out biosignatures on a microbial scale.
An X-ray spectrometer will target spots as small as a grain of table salt, while an ultraviolet laser will detect the “glow” from excited rings of carbon atoms.
A ground-penetrating radar will look under the surface of Mars, mapping layers of rock, water and ice up to 10 metres deep, depending on the material.
The rover is getting some upgraded Curiosity hardware, including colour cameras, a zoom lens and a laser that can vaporise rocks and soil to analyse their chemistry, NASA said.
The mission will also undertake a marathon sample hunt.
The rover team will try to drill at least 20 rock cores, and possibly as many as 30 or 40, for possible future return to Earth, NASA said.
Site selection has been another milestone for the mission. In February, the science community narrowed the list of potential landing sites from eight to three.
All three sites have rich geology and may potentially harbour signs of past microbial life. But a final landing site decision is still more than a year away.
“In the coming years, the 2020 science team will be weighing the advantages and disadvantages of each of these sites,” Farley said.
“It is by far the most important decision we have ahead of us,” Farley said.
The mission is set to launch in July/August 2020. (IANS)
Washington: The ozone hole over Antarctica shrank to its smallest peak since 1988, NASA said Thursday. The huge hole in Earth’s protective ozone layer reached its maximum this year in September, and this year NASA said it was 7.6 million square miles (19.6 million square kilometers). The hole size shrinks after mid-September.
This year’s maximum hole is more than twice as big as the United States, but it’s 1.3 million square miles smaller than last year and 3.3 million square miles smaller than 2015.
[ FILE – A false-color view of total ozone over the Antarctic pole is seen in this NASA handout image released Oct. 24, 2012. The purple and blue colors are where there is the least ozone. The average area covered by the Antarctic ozone hole in that year was the second smallest in two decades, at 8.2 million square miles; in September 2017, it was 7.6 million square miles ].
Paul Newman, chief Earth scientist at NASA’s Goddard Space Flight Center, said stormy conditions in the upper atmosphere warmed the air and kept the chemicals chlorine and bromine from eating ozone. He said scientists haven’t quite figured out why some years are stormier — and have smaller ozone holes — than others.
“It’s really small this year. That’s a good thing,” Newman said.
Newman said this year’s drop is mostly natural but is on top of a trend of smaller steady improvements likely from the banning of ozone-eating chemicals in a 1987 international treaty. The ozone hole hit its highest in 2000 at 11.5 million square miles (29.86 million square kilometers).
Ozone is a colorless combination of three oxygen atoms. High in the atmosphere, about 7 to 25 miles (11 to 40 kilometers) above the Earth, ozone shields Earth from ultraviolet rays that cause skin cancer, crop damage and other problems.
Scientists at the United Nations a few years ago determined that without the 1987 treaty, by 2030 there would have been an extra 2 million skin cancer cases. They said that overall, the ozone layer is beginning to recover because of the phase-out of chemicals used in refrigerants and aerosol cans. (VOA)