Massive Calved Iceberg Comes into View as Antarctic Sun Rises


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Massive Calved Iceberg Comes into View as Antarctic Sun Rises

Massive Calved Iceberg Comes into View as Antarctic Sun Rises
Instruments aboard the Landsat 8 satellite captured these visible and thermal images on Sept. 16, 2017, of the A68 iceberg that snapped off Antarctica’s Larsen C Ice Shelf.

Credit: NASA Earth Observatory

As the sun rises above the Antarctic horizon after the long, dark austral winter, scientists are getting a better look at the Delaware-size iceberg that sheared off from the frozen continent’s Larsen C ice shelf in July.

With the illumination from the sun’s rays, new satellite images have captured the iceberg, dubbed A68, and the motley assortment of ice and water surrounding it, in impressive detail. In the coming months and years, scientists will be poring over such images to watch the progression of the iceberg and its parent ice shelf.

The researchers said they also hope to study the area up close, to examinedetails of the seafloor that have been blocked by ice for hundreds of yearsand to learn how such a massive shift could alter the local ecosystem. [In Photos: Antarctica’s Larsen C Ice Shelf Through Time]

“It’s obviously a completely different physical environment once the ice is gone,” Susie Grant, a marine biogeographer with the British Antarctic Survey, told Live Science.

Keeping tabs on the iceberg, the ice shelf and the ecosystem in the coming years could also help scientists better understand how other major ice shelves might respond to a warming world, according to Grant.

Scientists have watched for several years as a rift slowly propagated its way across the Larsen C ice shelf, a platform of ice that extends out from the coast and floats atop the ocean. After a couple of surges in 2016 and earlier this year, the rift finally reached the edge of the ice shelf and calved off the iceberg.

Snapshot of the rift in the Larsen C on Nov. 10, 2016.

Credit: John Sontag/NASA

But with the sun below the Antarctic horizon, researchers could monitor the event only with thermal imagery and radar, according to NASA’s Earth Observatory.

“When it did finally break off, it was just sort of these tantalizing” glimpses, Grant said.

Once the sun re-emerged in August, more satellite views started streaming in ¾ and they haven’t disappointed. The “satellite images are extraordinary,” Grant said. “To see something of that scale moving across the water.”

In mid-September, NASA’s Terra satellite and the Landsat 8 satellite captured shots of the iceberg in visible light and of the surrounding area in infrared wavelengths of light. The images reveal exciting details, like the wrinkly-looking rifts that stretch across parts of the iceberg and the mixture of open water and ice surrounding it. [Earth from Above: 101 Stunning Images from Orbit]

An instrument onboard the Terra satellite captured this image of the A68 iceberg on Sept. 11, 2017.

An instrument onboard the Terra satellite captured this image of the A68 iceberg on Sept. 11, 2017.

Credit: NASA Earth Observatory

In the psychedelic thermal image, the cold iceberg and ice shelf appear a ghostly white, while the relatively warmer sea ice shows up in shades of purple, and the even warmer (though still sub-freezing) open water pops out in yellow. Bluer shades show the mixture of ice called mélange, which can include snow, sea ice, bits of ice that fell from the sides of the rift and something called marine ice, which forms along the underside of the floating ice, said Ala Khazendar, a scientist with NASA’s Jet Propulsion Laboratory who uses radar to study polar ice.

The images also show how much the iceberg has moved away from its parent ice shelf. So far, it has been progressing at a steady clip, but how fast it might continue to move is unclear and depends on several factors: winds and ocean currents, as well as whether there are any bumps or ridges on the seafloor that the iceberg might get stuck on, Khazendar said.

If it does get stuck, he said, that will tell scientists something about the topography of the seafloor, which they had no way of viewing before the calving event, Grant said.

That seafloor and the water above it are also being exposed to sunlight for the first time in at least hundreds of years, and this could have major impacts on the local ecosystem, Grant said. For instance, ocean life at the water’s surface could suddenly ramp up in productivity. The newly opened area could also see species moving in from neighboring regions, she said. [Antarctica Photos: Meltwater Lake Hidden Beneath the Ice]

The ecosystem will be “potentially dramatically changed” by the calving event, Grant said, though it’s “impossible to know anything about that until we can get down and visit.”

The British Antarctic Survey and other groups are planning scientific cruises to get an up-close look at the changes to the region, and the sooner that happens the better, so they can establish a baseline before major changes occur, Grant said. Sediment cores drilled from the ocean floor will help scientists establish how long the area has been covered by ice, and sampling of the water will tell them how the temperature and salt content may be changing and what creatures live there, she said.

Those efforts are helped by an international agreement by the Commission for the Conservation of Antarctic Marine Living Resources, which has 25 international members, to designate the area around the ice shelf as a protected area so that activities like commercial fishing won’t hamper scientific work, Gizmodo reported. This is the first time there has been such a designation, Grant said.

“I think that was a really important step,” she said. “We were really pleased to have managed to get that.”

In the meantime, scientists will glean what information they can from satellite images and airborne observations made by NASA’s IceBridge program, which is gearing up for the Antarctic summer season, Khazendar said.

Researchers will be watching to see if the remaining ice shelf begins to flow faster in response to the iceberg’s loss, he said, and how the iceberg melts and potentially breaks up into smaller pieces (one such piece already broke off later in July).

“We still need to collect data and analyze them in order to understand how the Larsen C ice shelf is going to react to this event,” Khazendar said.

There are concerns that the massive calving event could mark a turning point for the glacier, sending it toward a global warming-fueled collapse like those suffered by its northern neighbors, Larsen A and Larsen B, in 1995 and 2002, respectively. But whether that will happen isn’t yet clear, and the ice shelf could recover from the calving event, as these events do happen naturally, Khazendar said.

“It will take us some time before we have some clearer answers,” he said.

How Larsen C responds could also give scientists a better idea of how other major ice shelves around Antarctica will respond to the warming waters that are lapping away at the shelves’ undersides and causing the glaciers that feed into shelves to flow faster out to the ocean, raising sea levels.

“It could teach us a lot about the fate of other large ice shelves in Antarctica,” Khazendar said

Studying the region could also “improve our understanding of how ecosystems might respond to the impacts of climate change,” Grant said.

Original article on Live Science.

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These Stunning 3D Images Reveal How a Massive Greenland Glacier Has Changed


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These Stunning 3D Images Reveal How a Massive Greenland Glacier Has Changed

Watching a glacier

Credit: Jefferson Beck/NASA Goddard

What’s Causing So Many Earthquakes in Oklahoma?


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What’s Causing So Many Earthquakes in Oklahoma?

On Aug. 2, 2017, a 4.2-magnitude earthquake struck north central Oklahoma, a region that has seen an uptick in temblors since 2014.

Credit: USGS

A magnitude-4.2 earthquake hit just outside Edmond, Oklahoma, last night (Aug. 2) at 9:56 p.m. local time — the fifth significant temblor to shake this region of the state already this month, according to the U.S. Geological Survey.

The temblor originated at a depth of 1.9 miles (3 km), about 15 miles (24 km) northeast of Oklahoma City, the USGS said. According to the Edmond police department’s Twitter account, as of last night, no significant damage had been reported. News 9 in Oklahoma City reported that although 4,600 people were left without power after the quake, all power has since been restored. [The 10 Biggest Earthquakes in History]

But last night’s quake is part of a recent trend. Since Tuesday (Aug. 1), five earthquakes above magnitude 3.0 have been reported in this region, Xiaowei Chen, assistant professor of geophysics at the University of Oklahoma, told Live Science. It appears to be part of a longer sequence of earthquakes that began in 2014, she added. In fact, in 2014, the USGS issued an earthquake warning in the central part of the state — the first time the agency had ever issued such a warning for a state east of the Rockies.

Chen didn’t yet know enough about the most recent earthquake sequence to be able to comment on whether this recent magnitude-4.2 earthquake may signal that an even bigger earthquake will come, or if it’s simply within the range of expected seismic activity in the area, she said.

Although it’s difficult to attribute earthquakes to a particular cause, it’s possible that human activity induced this earthquake, William Yeck, a research geophysicist with the USGS Geologic Hazards Science Center, told Live Science. Since 2014, there has been a significant increase in the rate of earthquakes in north central Oklahoma, the area in which this recent earthquake occurred, he said.  The cause of this increase? Theinjection of wastewater — a byproduct of oil and gas production — into the ground may be to blame.

“The injection of fluids underground can increase underground pressures,” he said. “This, in turn, can effectively unclamp faults, allowing them to slip, which results in earthquakes.”

Last year, scientists reported that north central Oklahoma and the southernmost part of Kansas were at the greatest risk of a human-induced earthquake in the United States.

The high rate of earthquakes that began in 2014 began to drop off last year, which Yeck thinks may be due to the decrease in wastewater injection in this area.

“I just stress that [for] people [living] in an area that’s prone to earthquakes, preparedness is key,” he added.

Original article on Live Science.

 

Trillion-Ton Iceberg Breaks Off Antarctica


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Trillion-Ton Iceberg Breaks Off Antarctica

The European Space Agency’s Copernicus Sentinel-1 mission detected the huge chunk of ice that broke off Antarctica’s Larsen C ice shelf on July 12, 2017.

Credit: ESA

One of the largest icebergs ever recorded, packing about a trillion tons of ice or enough to fill up two Lake Eries, has just split off from Antarctica, in a much anticipated, though not celebrated, calving event.

A section of the Larsen C ice shelf with an area of 2,240 square miles (5,800 square kilometers) finally broke away some time between July 10 and today (July 12), scientists with the U.K.-based MIDAS Project, an Antarctic research group, reported today.

Scientists discovered the birth of this iceberg in data collected by an instrument aboard NASA’s Aqua satellite, called MODIS, which takes thermal infrared images. [In Photos: Antarctica’s Larsen C Ice Shelf Through Time]

The iceberg was expected, though scientists didn’t know when the crack in the ice sheet would finally release the floating chunk. The rift in the Larsen C ice shelf — the fourth-largest shelf in Antarctica — has been around for decades, but it wasn’t until November 2016 that satellite measurements revealed it had grown to more than 300 feet (91 m) in width and 70 miles (112 km) in length. The most recent measurements from this summer put the rift at 124 miles (200 km) long, with the now-calved iceberg hanging on by a thread; just 3 miles (5 km) of ice connected it with the rest of the ice shelf.

The Larsen C rift began to lengthen in January 2016. Images from July 12, 2017, show that part of the ice shelf had finally broken away.

The Larsen C rift began to lengthen in January 2016. Images from July 12, 2017, show that part of the ice shelf had finally broken away.

Credit: Swansea University/ESA

Even though the towering berg weighs more than 1.1 trillion tons (1 trillion metric tons), it won’t have a direct impact on sea-level rise. That’s because the ice was already floating on the sea. Even so, when an iceberg like this one calves, it can speed up the collapse of the rest of the ice shelf — the new iceberg reduced the area of the Larsen C ice shelf by 12 percent. Also, the ice shelf serves as a barrier to the land-based glacier that feeds the ice shelf; as that barrier diminishes, there’s more of a chance for the ice behind it to collapse into the sea, MIDAS researchers said.

And it’s this once-land-based ice that would impact sea levels, researchers say.

“Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position,” Martin O’Leary, a Swansea University glaciologist and member of the MIDAS project team, said in a statement. “This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable.”

As for what will happen to this huge chunk of ice, nobody knows at the moment.

“The iceberg is one of the largest recorded and its future progress is difficult to predict,” Adrian Luckman of Swansea University, lead investigator of the MIDAS project, said in the statement. “It may remain in one piece, but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters.”

Editor’s Note: This article was updated to clarify when the rift in the ice sheet first showed up. 

Original article on Live Science.

New Island Pops Up Off the Coast of North Carolina


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New Island Pops Up Off the Coast of North Carolina

New Island Pops Up Off the Coast of North Carolina
A new sandbar island has cropped up over the past few months just off the coast of North Carolina. Photographer Chad Koczera couldn’t get to the island on foot, so he sent a drone into the skies to capture this stunning image of the newly-formed island.

Credit: Courtesy of Chad Koczera

A new island suddenly emerged from the sea just off the coast of North Carolina — but officials warn that the spit of land is too dangerous for humans to explore.

The new sandbar island seemingly sprang from the ocean in just a few weeks, the Virginian Pilot reported. The island, which is about 1 mile (1.6 kilometers) long and about 480 feet (146 meters) wide, lies off the coast of Buxton, North Carolina, which is part of the Cape Hatteras National Seashore.

The new island grew from a mere nubbin in the ocean in April to its current size over Memorial Day weekend. One of the early explorers of the island, Janet Regan, took her 11-year-old son there to collect seashells. Because of its treasure trove of shells, the boy named it Shelly Island, the Pilot reported. [See Images of a Volcanic Island Birthed in Japan]

While the newborn island may be tantalizing for would-be explorers, it’s also very dangerous, Bill Smith, president of the North Carolina Beach Buggy Association, told the Pilot. Officials with the Cape Hatteras National Seashore have warned people not to try to reach the island.

Because the island formed near a popular fishing spot, years’ worth of fishing hooks could be lurking just below the sand. Sharks and stingrays prowl just beneath the water’s surface in the area, and the narrow 50-foot (15 m) strip of water between the island and the mainland forms a little “river” that creates a strong rip current, he said.

“We’re worried about shark bites, but we’re more worried about drownings,” Smith said.

The sandbar isn’t accessible by foot, so photographer Chad Koczera sent a drone into the skies to capture a stunning aerial photo. More intrepid (or foolhardy) explorers also have tried to reach the island by boat or paddleboard, the Pilot reported.

The area of coastline near the island is always transforming, according to a statement from the Cape Hatteras National Seashore. The point, called Cape Point, sometimes changes orientation, and currents and storms are constantly shaping the land. It’s likely that such forces formed the sandbar, meaning it could get even bigger or sink beneath the waves in the next year or two, Smith said.

If anyone does attempt a trip to the island, National Seashore Superintendent David Hallac said such a trip “is best accomplished by experienced kayakers or paddle boarders that are using appropriate flotation and mindful of the tides and strong currents in the area.”

Originally published on Live Science

Photos of Siberia’s Mysterious Craters


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Photos of Siberia’s Mysterious Craters

Seven giant craters have mysteriously appeared in northern Siberia, possibly due to methane gas released from melting permafrost. Check out these jaw-dropping photos of the strange geological structures. [Read full story about the Siberian craters]

This crater, in the Yamal Peninsula, was discovered in 2014 by helicopter pilots 19 miles (30 kilometers) from Bovanenkovo, a major gas field in the Yamalo-Nenets autonomous district. (Image credit: Marya Zulinova/The Siberian Times)


Four Arctic craters can be seen in this satellite image: B1, the famous Yamal hole located 19 miles (30 kilometers) from Bovanenkovo; B2, the recently discovered crater located 6.2 miles (10 km) south of Bovanenkovo; B3, a crater located 56 miles (90 km) from Antipayuta village; and B4, a crater located near Nosok village, north of the Krasnoyarsk region near Taymyr Peninsula. (Image credit:Vasily Bogoyavlensky)

Satellite image of the site before the formation of the Yamal hole (B1). K1 and the red outline show the hillock formed before the emission of methane gas. Yellow outlines show potentially dangerous areas where gas could erupt. (Image credit: Marya Zulinova/The Siberian Times)


Satellite images showing a mound of Earth before the gas emission that formed crater B2 (top). Lakes formed at a couple of the craters, and more than 20 smaller craters were found nearby (bottom). (Image credit: Marya Zulinova/The Siberian Times)


The Yamal lake showing signs of gas emission. (Image credit: Marya Zulinova/The Siberian Times)


Crater B3, located 56 miles (90 km) from Antipayuta village, Yamal district (top). Crater B4, located near Nosok village, north of the Krasnoyarsk region, near Taymyr Peninsula. (Image credit: local residents/The Siberian Times)


The ring of soil around these craters suggests an underground explosion. (Image credit: Vasily Bogoyavlensky/The Siberian Times)


The Russian Center of Arctic Exploration embarked on an expedition to Yamal crater in early November 2014. The researchers were the first in the world to climb down into the crater. (Image credit: Vladimir Pushkarev/The Siberian Times)

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Oozing Methane Blasts Holes in Siberian Tundra


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Oozing Methane Blasts Holes in Siberian Tundra

A crater on the Yamal Peninsula in Siberia, reported in the spring of 2017.

Credit: Itar-Tass/Zuma

Escaping methane gas has blown at least two new holes in the Siberian tundra in the past few months, according to eyewitness accounts to the Siberian Times and the Russian Academy of Sciences.

Reindeer herders northwest of the village of Seyakha in Siberia’s far north reported seeing an eruption of fire and smoke on the morning of June 28 — an event caught on seismic sensors at 11 a.m. local time, according to The Siberian Times. Scientists visiting the site photographed a fresh crater blown into the banks of a river.

Researchers also discovered a second, previously unknown crater in the Tyumen region of Siberia this month, the newspaper reported. Local herders told Aleksandr Sokolov, a researcher at the Institute of Ecology of Plants and Animals in Russia, that they’d observed fire in the area of that crater in the winter or early spring.

When permafrost melts, it releases large amounts of methane. According to Russian scientists, this sudden release could have led to the explosions. How fast and how frequently this is happening remain controversial topics in the scientific community, given that Siberia is so remote and unexplored. But scientists do agree that Siberia’s permafrost is in danger of melting as the globe warms.

Permafrost is soil that stays frozen all year long. Any organic matter, like dead grass or animal corpses, caught up in permafrost stays frozen, too. But as the Arctic warms, the depth of the spring thaw gets deeper and deeper — a process called active-layer deepening. As the soil thaws, the organic material locked inside begins to decompose all at once, releasing flammable gases such as methane, University of Michigan postdoctoral researcher Ben Abbott told Live Science in March.

In some cases, this release is slow, Abbott said. Other times, the soil can collapse dramatically, creating features called thermokarsts. These can look like landslides, slumps, pits or craters. Some fill with water and become lakes.

Past research suggests that warming can cause explosive changes in the landscape. A study released in June found that at least 100 giant cratersformed in one region on the Arctic seafloor about 11,600 years ago as the ice sheet retreated and destabilized mounds of frozen methane underneath. These mounds, call pingos, sometimes blew craters up to 0.6 miles (1 kilometer) wide into the ocean bottom.

Some Arctic scientists think something similar is happening in Siberia today. Pingos, or soil-covered permafrost hills, occur on land, too. If they melt rapidly, they could release a fiery burst of methane and create craters similar to the ancient ones seen on the seafloor. Previously, Siberian researchers had discovered craters that had never been seen before, but they had not published any information on the ages of the craters or scientific analyses of how they’d formed. The new eyewitness accounts from local herders suggest that the formation of these craters may, indeed, be violent.

Though the region of Siberia where these craters are located is remote, Russian authorities are concerned about the explosions caused by melting permafrost. The crater that formed on June 28 is about 60 miles (100 km) from Sabetta, a newly developed port on the Ob River that’s used to transport liquefied natural gas from the Yuzhno-Tambeyskoye gas field, The Siberian Times reported.

“It is very important for us also to know what to do, because such an eruption can occur anywhere,” Alexander Mazharov, deputy governor of the Yamalo-Nenets autonomous region in Siberia, told The Siberian Times. “It might hit a technical facility, a residential settlement or a linear object,” he said, referring to a pipeline or railroad.

Original article on Live Science.