Tag Archives: Antarctica

Antarctica gives birth to world’s largest iceberg

By Steve Gorman

(Reuters) -A giant slab of ice bigger than the Spanish island of Majorca has sheared off from the frozen edge of Antarctica into the Weddell Sea, becoming the largest iceberg afloat in the world, the European Space Agency said on Wednesday.

The newly calved berg, designated A-76 by scientists, was spotted in recent satellite images captured by the Copernicus Sentinel-1 mission, the space agency said in a statement posted on its website with a photo of the enormous, oblong ice sheet.

Its surface area spans 4,320 square km (1,668 square miles) and measures 175 km (106 miles) long by 25 km (15 miles) wide.

By comparison, Spain’s tourist island of Majorca in the Mediterranean occupies 3,640 square km (1,405 square miles). The U.S. state of Rhode Island is smaller still, with a land mass of just 2,678 square km (1,034 square miles).

The enormity of A-76, which broke away from Antarctica’s Ronne Ice Shelf, ranks as the largest existing iceberg on the planet, surpassing the now second-place A-23A, about 3,380 square km (1,305 square miles) in size and also floating in the Weddell Sea.

Another massive Antarctic iceberg that had threatened a penguin-populated island off the southern tip of South America has since lost much of its mass and broken into pieces, scientists said earlier this year.

A-76 was first detected by the British Antarctic Survey and confirmed by the Maryland-based U.S. National Ice Center using imagery from Copernicus Sentinel-1, consisting of two polar-orbiting satellites.

The Ronne Ice Shelf near the base of the Antarctic Peninsula is one of the largest of several enormous floating sheets of ice that connect to the continent’s landmass and extend out into surrounding seas.

Periodic calving of large chunks of those shelves is part of a natural cycle, and the breaking off of A-76, which is likely to split into two or three pieces soon, is not linked to climate change, said Ted Scambos, a research glaciologist at the University of Colorado at Boulder.

Scambos said the Ronne and another vast ice shelf, the Ross, have “behaved in a stable, quasi-periodic fashion” over the past century or more. Because the ice was already floating in the sea before dislodging from the coast, its break-away does not raise ocean levels, he told Reuters by email.

Some ice shelves along the Antarctic peninsula, farther from the South Pole, have undergone rapid disintegration in recent years, a phenomenon scientists believe may be related to global warming, according to the U.S. National Snow & Ice Data Center.

(Reporting by Steve Gorman in Los Angeles; Editing by Peter Cooney)

Coronavirus reaches end of earth as first outbreak hits Antarctica

By Natalia A. Ramos Miranda

SANTIAGO (Reuters) – The coronavirus has landed in Antarctica, the last continent previously free from COVID-19, Chile’s military said this week, as health and army officials scrambled to clear out and quarantine staff from a remote research station surrounded by ocean and icebergs.

Chile’s armed forces said at least 36 people had been infected at its Bernardo O’Higgins base, including 26 army personnel and 10 civilian contractors conducting maintenance at the base.

The permanently staffed research station, operated by Chile’s army, lies near the tip of a peninsula in northernmost Antarctica, overlooking a bay often dotted with icebergs.

Base personnel “are already properly isolated and constantly monitored” by health authorities in Magallanes, in Chilean Patagonia, the army said, adding there had so far been no complications.

Research and military stations in Antarctica – among the most remote in the world – had gone to extraordinary lengths in recent months to keep the virus out, canceling tourism, scaling back activities and staff and locking down facilities.

Researchers with the British Antarctic Survey estimate about 1,000 people at 38 stations across the frozen continent had safely navigated the southern hemisphere winter without incident. But an uptick in travel to and from the region this spring and early summer have heightened infection risk.

An Army press officer said the first COVID-19 cases had been reported in mid-December, when two soldiers fell ill.

The Magallanes region, one of the closest populated areas to Antarctica and take-off point for many boats and planes headed to the continent, is among the hardest-hit in Chile.

Much of the area, blasted by cold winds off the ocean, mountains and glaciers, has been under quarantine restrictions for months.

Chile’s Navy reported it too had detected three cases of COVID-19 among 208 crew members of a ship that had sailed in the Antarctic region between Nov. 27 and Dec. 10.

(Reporting by Natalia Ramos; Additional reporting by Aislinn Laing and Reuters TV; Writing by Dave Sherwood; Editing by Bill Berkrot)

Antarctica rocked by 30,000 tremors in 3 months, Chilean scientists say

SANTIAGO (Reuters) – More than 30,000 tremors have rocked Antarctica since the end of August, according to the University of Chile, a spike in seismic activity that has intrigued researchers who study the remote, snowbound continent.

Scientists with the university’s National Seismological Center said the small quakes – including one stronger shake of magnitude 6 – were detected in the Bransfield Strait, a 60-mile wide (96-km) ocean channel between the South Shetland Islands and the Antarctic Peninsula.

Several tectonic plates and microplates meet near the strait, leading to frequent rumbling, but the past three months have been unusual, according to the center.

“Most of the seismicity is concentrated at the beginning of the sequence, mainly during the month of September, with more than a thousand earthquakes a day,” the center said.

The shakes have become so frequent that the strait itself, once increasing in width at a rate of about 7 or 8 mm (0.30 inch) a year is now expanding 15 cm (6 inches) a year, the center said.

“It’s a 20-fold increase … which suggests that right this minute … the Shetland Islands are separating more quickly from the Antarctic peninsula,” said Sergio Barrientos, the center’s director.

The peninsula is one of the fastest-warming places on Earth, and scientists closely monitor the changing climate’s impact on its icebergs and glaciers.

But climate scientist Raul Cordero of the University of Santiago said it was not yet clear how the tremors might be affecting the region’s ice.

“There’s no evidence that this kind of seismic activity … has significant effects on the stability of polar ice caps,” Cordero told Reuters.

(Reporting by Fabian Cambero and Reuters TV; Writing by Dave Sherwood; Editing by Peter Cooney)

Antarctica ice shelves vulnerable to meltwater that could cut ice ‘like a knife,’ study finds

By Cassandra Garrison

BUENOS AIRES (Reuters) – Meltwater could undermine the walls of ice holding back Antarctica’s glaciers, scientists reported on Wednesday, a finding that underscores concern about the potential for a significant sea level rise.

The ice shelves, formed over thousands of years, serve as dams to prevent much of the continent’s snow and ice from flowing toward the ocean. Scientists found that about 60% of the ice shelf area is vulnerable to a process call hydro-fracturing, in which meltwater seeps into the shelves’ crevasses, some of which are hundreds of meters deep, and triggers collapse.

“This meltwater is heavier than ice, so it can penetrate through the entire ice thickness, just like a knife,” said climate scientist Ching-Yao Lai at Colombia University.

It’s unclear how long such a process might take. Antarctic weather is highly variable, making it difficult for scientists to determine how much of a role is being played by human-caused climate change.

Lai said, however, that previous research suggested meltwater could cover the ice shelves in about a century.

The new study, published in the journal Nature, used AI to identify ice-fracture features in nearly 260 satellite images of 50 ice shelves across the continent. Those ice shelves surround about 75% of the Antarctic coastline.

Finding vulnerabilities in the ice shelves buttressing the glaciers above was a surprise, Lai said.

“Previously, we thought there are going to be places vulnerable to hydro-fracture, but that those places might not matter at all for the ice sheet,” Lai said.

Scientists fear that losing ice shelves to hydro-fracturing will leave Antarctica’s ice sheets a more direct pathway to the ocean, which could accelerate ice loss and contribute to sea level rise.

The latest reports by the Intergovernmental Panel on Climate Change have projected future sea levels to rise by more than a meter by 2100. However, scientists worry that a sudden collapse of these steep ice shelves could increase future sea levels dramatically. More than half of the world’s fresh water is locked into Antarctica’s ice.

Meanwhile, warming temperatures driven by climate change are also eating into glaciers and the ice sheet in the Arctic. Last month, Canada’s last intact ice shelf collapsed.

And Greenland’s ice sheet lost a record amount of mass last year, raising concerns the icy bulk is melting more quickly than anticipated. Greenland’s ancient ice sheet holds enough water to raise sea levels by at least 20 feet (6 meters) if it were to melt entirely.

In Antarctica, if “we start seeing the collapse of some of this ice that is there like a wall holding back everything behind it, it’s just going to accelerate the pace of sea level rise beyond what we’re probably predicting right now,” said Alexandra Isern, head of Antarctic studies for the U.S. National Science Foundation who was not involved in the study.

Once gone, the ice shelves wouldn’t be able to form again “in any time we’ll ever see,” Isern said. “It took a long time to make them, and it maybe isn’t going to take as long to get rid of them.”

Scientists say that, while governments should prepare for higher seas, there is still time to curb climate-warming emissions in order to slow the rate of sea level rise and avoid coastal catastrophes.

“There’s no ice on the planet that gets along well with warming air and warming ocean temperatures,” said glaciologist Twila Moon at the National Snow and Ice Data Center who was not involved in the study.

“These kinds of details and tools are helping us to narrow our range of being able to say what will happen in the future, given that humans follow any particular path.”

(Reporting by Cassandra Garrison; Editing by Katy Daigle and Bernadette Baum)

Midwest U.S. in brutal grip of colder-than-Antarctica deep freeze

A pedestrian stops to take a photo by Chicago River, as bitter cold phenomenon called the polar vortex has descended on much of the central and eastern United States, in Chicago, Illinois, U.S., January 29, 2019. REUTERS/Pinar Istek

By Suzannah Gonzales

CHICAGO (Reuters) – Frozen Arctic winds brought record-low temperatures across much of the U.S. Midwest on Wednesday, unnerving residents accustomed to brutal winters and keeping them huddled indoors as offices closed and even mail carriers halted their rounds.

Classes were canceled Wednesday and Thursday in many cities, including Chicago, home of the nation’s third-largest school system, and police warned of the risk of accidents on icy highways.

Man blows snow during a winter storm in Buffalo, New York, U.S., January 30, 2019. REUTERS/Lindsay Dedario

Man blows snow during a winter storm in Buffalo, New York, U.S., January 30, 2019. REUTERS/Lindsay Dedario

In a rare move, the U.S. Postal Service appeared to temporarily set aside its credo that “neither snow nor rain … nor gloom of night” would stop its work: it halted deliveries from parts of the Dakotas through Ohio.

Temperatures in parts of the Northern Plains and Great Lakes plunged to as low minus 42 Fahrenheit (minus 41 Celsius) in Park Rapids, Minnesota, and minus 31F in Fargo, North Dakota, according to the National Weather Service. The frigid winds were bound for the U.S. East Coast later on Wednesday into Thursday.

Andrew Orrison, a meteorologist with the service, said the some of the coldest wind chills were recorded in International Falls, Minnesota, at minus 55F (minus 48C). Even the South Pole in Antarctica was warmer, with an expected low of minus 24F (minus 31C) with wind chill.

The bitter cold was caused by a displacement of the polar vortex, a stream of air that normally spins around the stratosphere over the North Pole, but whose current was disrupted and was now pushing south.

An Illinois police department found a fictitious cause for the icy blast, posting on Facebook that its officers had arrested Elsa, the frosty character from the Disney movie “Frozen,” for bringing the arctic air to the Midwest.

Aftermath of an accident in Grand Rapids, Michigan, U.S., January 29, 2019 in this picture obtained from social media. Picture taken January 29, 2019. JASON COFFELT/via REUTERS

Aftermath of an accident in Grand Rapids, Michigan, U.S., January 29, 2019 in this picture obtained from social media. Picture taken January 29, 2019. JASON COFFELT/via REUTERS

The McLean Police Department shared a staged photo of officers putting a woman dressed in a blue princess gown in pink handcuffs and escorting her into a police car.

Officials opened warming centers across the region, and in Chicago, police stations were open to anyone seeking refuge from the cold. Five city buses were also deployed to serve as mobile warming centers for homeless people.

The Chicago Police Department said that at most, it could encourage people to get out of the cold.

“But we will never force someone,” police officer Michael Carroll said.

At least five deaths relating to cold weather have been reported since Saturday in Iowa, Indiana, Illinois, Wisconsin and Minnesota, local media reports said.

Hundreds of flights, more than half of those scheduled, were canceled on Wednesday out of Chicago O’Hare and Chicago Midway international airports, according to the flight tracking site FlightAware.

Train service Amtrak said it would cancel all trains in and out of Chicago on Wednesday.

Most federal government offices in Washington D.C. opened three hours late on Wednesday due to the frigid weather already impacting the area.

(Reporting by Suzannah Gonzales, additional reporting by Rich McKay in Atlanta, and Gina Cherelus and Jonathan Allen in New York; Editing by Scott Malone and Bernadette Baum)

Antarctic thaw quickens, trillions of tonnes of ice raise sea levels

By Alister Doyle Environment Correspondent

OSLO (Reuters) – An accelerating thaw of Antarctica has pushed up world sea levels by almost a centimeter since the early 1990s in a risk for coasts from Pacific islands to Florida, an international team of scientists said on Thursday.

Antarctica has enough ice to raise seas by 58 meters (190 ft) if it ever all melted, dwarfing frozen stores in places from Greenland to the Himalayas and making its future the biggest uncertainty in understanding global warming and ocean levels.

The frozen continent lost almost three trillion tonnes of ice between 1992 and 2017, the 84 scientists said in what they called the most complete overview of Antarctic ice to date.

The thaw, tracked by satellite data and other measurements, contributed 0.76 cm to sea level rise since 1992, they wrote in the journal Nature.

And the ice losses quickened to 219 billion tonnes a year since 2012, from 76 billion previously. “The sharp increase … is a big surprise,” professor Andrew Shepherd of the University of Leeds and a leader of the report, told Reuters.

Most ice was being lost from West Antarctica and the Antarctic Peninsula, where warmer ocean water is melting floating ice shelves at the end of glaciers, allowing ice pent up on land to slide faster toward the sea, the study said.

A single millimeter of global sea level rise is equivalent to 360 billion tonnes of melted ice, or an imaginary gigantic ice cube with sides about seven kilometers (4.35 miles) long.

Overall, world sea levels have risen about 20 cm in the past century, driven mainly by a natural expansion of water already in the oceans as it warms along with a thaw of glaciers form the Andes to the Alps.

And a major U.N. assessment in 2014 said seas could rise this century by between about 30 cm and almost a meter.

Shepherd said Antarctica alone is now on track to raise world sea levels by about 15 cm by 2100, above most past estimates.

Such a rise alone sounds little but would make coastal floods during storms at high tides more damaging, he said. Sea level rise is a threat to cities from New York to Shanghai as well as low-lying nations from the Pacific Ocean to the Netherlands.

“We’re watching these reports closely,” said Michiel van den Broeke, professor of Polar Meteorology at Utrecht University in the Netherlands, saying they were the guide for defending the Dutch coast.

Under the 2015 Paris climate agreement, almost 200 governments set a goal of phasing out fossil fuels this century to limit warming. U.S. President Donald Trump plans to pull out of the pact and to focus instead on U.S. jobs and coal.

Chris Rapley, a professor of climate science at University College London who was not involved in the study, wrote in a comment that he had suggested in 2005 that a “slumbering giant (of ice in Antarctica) seemed to be awakening. This paper suggests it is stretching its limbs.”

(Reporting By Alister Doyle; Editing by Matthew Mpoke Bigg)

Giant iceberg breaks off Antarctica

FILE PHOTO: An aerial view of the rift in the Larsen C seen in an image from the Digital Mapping System over the Antarctica Peninsula, Antarctica, on November 10, 2016. NASA's Goddard Space Flight Center/Handout via REUTERS/File Photo ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY

By Nina Chestney

LONDON (Reuters) – One of the biggest icebergs on record has broken away from Antarctica, scientists said on Wednesday, creating an extra hazard for ships around the continent as it breaks up.

The one trillion tonne iceberg, measuring 5,800 square km, calved away from the Larsen C Ice Shelf in Antarctica sometime between July 10 and 12, said scientists at the University of Swansea and the British Antarctic Survey.

The iceberg has been close to breaking off for a few months. Throughout the Antarctic winter, scientists monitored the progress of the rift in the ice shelf using the European Space Agency satellites.

“The iceberg is one of the largest recorded and its future progress is difficult to predict,” said Adrian Luckman, professor at Swansea University and lead investigator of Project MIDAS, which has been monitoring the ice shelf for years.

“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,” he added.

The ice will add to risks for ships now it has broken off. The peninsula is outside major trade routes but the main destination for cruise ships visiting from South America.

In 2009, more than 150 passengers and crew were evacuated after the MTV Explorer sank after striking an iceberg off the Antarctic peninsula.

The iceberg, which is likely to be named A68, was already floating before it broke away so there is no immediate impact on sea levels, but the calving has left the Larsen C ice shelf reduced in area by more than 12 percent.

The Larsen A and B ice shelves, which were situated further north on the Antarctic Peninsula, collapsed in 1995 and 2002, respectively.

“This resulted in the dramatic acceleration of the glaciers behind them, with larger volumes of ice entering the ocean and contributing to sea-level rise,” said David Vaughan, glaciologist and director of science at British Antarctic Survey.

“If Larsen C now starts to retreat significantly and eventually collapses, then we will see another contribution to sea level rise,” he added.

Big icebergs break off Antarctica naturally, meaning scientists are not linking the rift to manmade climate change. The ice, however, is a part of the Antarctic peninsula that has warmed fast in recent decades.

“In the ensuing months and years, the ice shelf could either gradually regrow, or may suffer further calving events which may eventually lead to collapse – opinions in the scientific community are divided,” Luckman said.

“Our models say it will be less stable, but any future collapse remains years or decades away.”

(Editing by Toby Chopra)

World Temperature Record Set

NASA scientists report that a new world’s record for lowest recorded temperature has been set in Antarctica.

Analysis of NASA satellite data shows an area of the icy continent at -135.8 degrees Fahrenheit. The new mark shatters the old record of -128.6 degrees.  While the record was set in 2010, NASA released the data today in a press release.

Ted Scambos of the National Snow and Ice Data Center said those conditions could easily be deadly to humans.

“I am told that every breath is painful and you have to be extremely careful not to freeze part of your throat or lungs when inhaling,” Scambos said in a statement.

Scambos said the temperature record was only an accidental discovery. His team has been studying unusual cracks on the surface of eastern Antarctica and believed the cracks are “thermal cracks”. Thermal cracks happen when the temperature is so low that snow shrinks to the point the surface cracks.

“The record-breaking conditions seem to happen when a wind pattern or an atmospheric pressure gradient tries to move the air back uphill, pushing against the air that was sliding down,” Scambos said. “This allows the air in the low hollows to remain there longer and cool even further under the clear, extremely dry sky conditions. When the cold air lingers in these pockets it reaches ultra-low temperatures.”