Human activity, threat to Antarctic ecosystem

This year, we celebrate the 100th year anniversary of Roald Amundsen’s conquest of The South Pole for Norway on December 14th, 1911. Today, one century later, scientists find out that human activity is a threat to the Antarctic ecosystem, as reported in The Hindu on May 18th, 2011.

Hornfar

AFP

A team of scientists has warned that the native fauna and unique ecology of the Southern Ocean, the body of water that surrounds the Antarctic continent, is under threat from human activity.

Original article here

Invasive Species Carried Steadily in the Antarctic

Softpedia news, April 29th, 2011 – original article here

Antarctica was until recently the most pristine continent in the world, but that situation is currently changing. Research scientists, tourists, and just about anyone who sets foot around the South Pole, are carrying bacteria and other organisms that are not indigenous to this area.

For all intents and purposes, we are promoting an invasion that could see the establishing of new species in this clean habitat. While the harsh conditions in Antarctica will take care of most intruders, there are those that will undoubtedly survive.

Some microorganisms are known for being able to survive in space for prolonged periods of time, so they can surely endure in a bit of ice, scientists say. The same holds true for plant seeds that are being involuntarily and steadily carried on the Southern Continent.

 The main risk with invasive species is that they tend to overtake a new habitat by killing off indigenous species. The latter spent millions of years adapting to their environment, and achieving an ecosystemic balance, only to have it all taken away by opportunistic organisms.

“We are still at the stage when Antarctica has fewer than 10 non-native species, none of which have become invasive. Unless we take steps now to minimize the risk of introduction, who knows what will happen,” says expert Kevin Hughes.

The investigator, who holds an appointment as an environmental scientist at the British Antarctic Survey (BAS), analyzed some 11,250 pieces of fresh produce in a new study. Together with colleagues, he was trying to determine how many new organisms make their way in the Antarctic via this route.

Experts found 56 invertebrates, which included aphids, butterflies, spiders and snails. Large amounts of soil were discovered on many produce, and more than a quarter of all were rotten due to microbes.

“Are these numbers surprising, or does it mean this is likely to be a problem? It’s pretty hard to say,” comments Daniel Simberloff, an expert who was not a part of the new research.

“The upshot is that there’s just enough people going to some parts of Antarctica nowadays that lots of organisms are carried there,” adds the scientist, who is a professor at the University of Tennessee in Knoxville.

“I have to think this isn’t good, and some subset of them are going to pose environmental problems,” he goes on to say, quoted by LiveScience.

“To be quite honest, the only way we are going to stop the introduction of nonnative species is to stop going to Antarctica, to cut off all the pathways. What we can do is try and minimize the risk of introduction and we can do that by relatively simple steps,” Hughes adds further.

Japan quake shifts Antarctic glacier, New Scientist reports

15:45 15 March 2011 by Anil Ananthaswamy
Original article here

The major earthquake that hit Japan on Friday caused a massive ice stream in Antarctica to momentarily speed up.

As the surface seismic waves generated by the quake travelled around the world, they appear to have given the Whillans ice stream in West Antarctica a nudge, causing it to slide by about half a metre.

The movement was picked up by Jake Walter of the University of California, Santa Cruz, and his colleagues, who monitor the glacier remotely from California. They say the event is an “interesting insight”, but are not suggesting it will destabilise the ice stream in any way.

The Whillans ice stream drains ice from the West Antarctic Ice Sheet into the Ross Ice Shelf. Since 2007, Walter and colleagues have been using GPS field stations on the ice sheet to monitor its movements. They have shown that the ice stream speeds up twice a day in slip events which last about 30 minutes.

The glacier normally creeps along at an average speed of about 1 metre per day. But during a slip event, it slides almost half a metre in one go. The sudden slips are related to the tides, and are strong enough to generate seismic waves that are recorded by stations at the South Pole and the Antarctic Dry Valleys (Journal of Geophysical Research, DOI: 10.1029/2010JF001754).

Slipping glacier

Now it looks like the magnitude 9.0 earthquake that shook Japan last Friday caused the glacier to slip in a similar way.

When Walter and his colleagues were analysing GPS data from the ice stream on Monday, they noticed that one slip event had happened earlier than expected. Further analysis revealed that it happened exactly when surface seismic waves generated by the Japanese earthquake would have hit Antarctica.

Large earthquakes are known to create seismic waves which can circle the planet several times before dying down.

“The Chile earthquake from last year also had a similar effect” on the Whillans ice stream, Walter told New Scientist. “It’s an interesting insight into how large earthquakes might affect glacier motion.”

Walter and colleagues now want to examine data from other large earthquakes to see if any others are linked to slip events of the Whillans ice stream.

US Demolishes Old Antarctic Bases

Softpedia. com, March 11th, 2011 – Original article here

Since the American flag was planted at the South Pole, on October 31, 1956, the United States constructed three research facilities in Antarctica. Recently, two of them were demolished, and the only structure remaining is a high-tech, latest-generation lab that is perched on stilts.

[I have to add here that the Norwegian flag was planted on the South Pole on December 14th 1911, 45 years before the Americans… and 100 years ago this year. Hornfar]

Image showing the destruction of the Old Pole station. Image credits: Robert Schwarz

For the past 55 years, the US has had a constant presence at the South Pole in terms of science. Its stations were ahead of their time as far as the engineering complexity and technology needed to build them went.

But, with the construction of the new facility, it became clear that there was simply too much effort to manage the separate stations, when a single, advanced one was enough. The costs of maintaining a crew in the Antarctic are very steep, and researchers often deal with lack of appropriate funding.

The Dome Station was disassembled in 2010. The US Antarctic Program had made the announcement some time before, mentioning that the structure had far outlived its shelf life, and that it was becoming a menace for people venturing within.

During this season’s austral summer, construction workers also demolished the original Antarctic station (the Old Pole), which was built for the International Geophysical Year (IGY) of 1957-58.

“It took a lot of effort and a lot of people. But we got it done in a timely fashion,” says of the effort Andres Martinez, who is the South Pole Technical Support manager. He is now based in the new research station, which isn’t actually new, since it was opened in January 2008.

He explains that the first South Pole Station remained occupied for nearly 20 years, even if it was put together hastily, and was buried by Mother Nature under feet of snow. The ice that subsequently formed endangered its crew constantly, and maintenance work needed to be conducted at all times.

“The old station, no longer the object of structural or mechanical improvements, gamely carried on. It showed its years in the distortion of buildings, metal arches, and shoring timbers,” wrote Dick Wolak.

“Its generators were a constant problem, and often irregular in their output. The patchwork of devices used to heat buildings and provide water was notably inefficient in its use of costly diesel fuel.” he added.

The expert was the civilian South Pole Station manager between 1974 and 1975, as researchers were in a period of transition between the Old Pole station and the then-new Dome Station.

Following a series of accidents involving heavy equipment falling through the unstable ices covering the Old Pole station, the US National Science Foundation decided to implode it during the austral summer.

The support beams that held the structure together were blown up, and snow is now forming new ice where researchers worked nearly 20 years for unraveling the mysteries surrounding the Antarctic, SpaceRef reports.

Penguin Colony in the Antarctic Disappears

Softpedia News, March 5th, 2011 Original article here

Map 2: Emperor Island, Dion Islands, ASPA No. 107: topographic map. Map specifications: Projection: Lambert Conformal Conic; Standard parallels: 1st 67° 0' 00" W; 2nd 68° 00' 00"S; Central Meridian: 68° 42' 30" W; Latitude of Origin: 68° 00' 00" S; Spheroid: WGS84; Datum: Mean sea level. Horizontal accuracy: ± 1.5 m; Vertical accuracy ±1 m (best accuracy of the control points); Vertical contour interval 5 m (index contour interval 15m).

Biologists have documented the first instance of what they call the global warming-induced disappearance of an animal colony. The experts can no longer find even the smallest traces of a small colony of penguins that once lived on an island off the coasts of Antarctica.

It has been proposed a long time ago that penguins would be among the most affected species when climate change finally struck, right alongside other ice-dependent animals, like polar bears.

But no one documented an actual case of that happening until now. Experts believe that the emperor penguin colony disappeared because of dwindling sea ices around their home island.

The island in question is located off the West Antarctic Peninsula, which is one of the areas that lost the most ice due to the warming climate. Without the shelfs to provide them with support and food, the penguins most likely could not secure enough to eat.

When the Emperor Island colony was first discovered in 1948, it featured about 150 breeding pairs of penguins. An 1978 report showed a sharp decline in numbers, while a 2009 aerial survey found the entire island deserted.

One of the biggest unknowns in this study is whether the penguins died off, or just relocated to a more hospitable environment, says lead researcher Philip Trathan. He holds an appointment as a conservation biologist as the British Antarctic Survey (BAS), LiveScience reports.

An explanation could be that fewer and fewer emperor penguins returned to this location over the years. The animals live for about 20 years, and they tend to return yearly to the site where they hatched.

Over time, it could be that more and more parents from the Emperor Island colony laid their eggs elsewhere. As such, the new generation did not return to the former colony, because they did not know where it was, and had no connection to it.

On the other hand, the researchers did find a connection to climate change and rising temperatures. “The one site in Antarctica where we have seen really big changes is the West Antarctic Peninsula,” Trathan explains in the February 28 issue of the journal PLoS ONE.

Ices in this region were observed over the past two decades forming about 54 days later than normal, and melting some 31 days earlier. This may have also contributed to the decline of the penguin colony. These birds are completely reliant on ice for most of their activities.

The BAS team admits that more studies are required to establish a clear cause for the penguins’ disappearance. “We need to look at more colonies so we can reduce the uncertainty. With the first report, there is a high degree of uncertainty,” the BAS team leader concludes.

Navy Vet: Antarctic Mission Gave Sailors Cancer

Navy Sent Crews To Antarctica For ‘Operation Deep Freeze’ In 1960s

10 News, San Diego on March 4, 2011 Original article here

A retired San Diego sailor told 10News he knows why thousands of Navy veterans are suffering from or dying from cancer.

Bill Vogel said he believes the cancer many fellow veterans have been stricken with was caused by a mission to the Antarctic called “Operation Deep Freeze.” Vogel said the mission was for scientific research.

10News learned at least 15,000 military personnel were a part of the mission over the course of nearly a decade and all of them worked near a malfunctioning nuclear power plant.

The McMurdo Nuclear plant was built in Antarctica in the early 1960s and provided power to the base until it was shut down in 1972.

The Navy’s final operating report found the plant suffered from 438 malfunctions during its operation, including leaking water surrounding the reactor and hairline cracks in the reactor liner.

The plant was dismantled when “possible stress corrosion cracking” in the piping system was discovered.

The Navy’s final report didn’t find evidence of excessive radiation exposure.

Vogel’s friend, Charlie Swinney, died a year ago from cancer. Swinney was one of many naval veterans who had similar concerns about their service at McMurdo after being diagnosed with cancerous tumors.

“Charlie had over 200 tumors in his body,” Swinney’s wife, Elaine, said from their Cleveland home.

“He kept saying, ‘This isn’t right. Why are there so many of us in this close group getting sick like this,'” she said.

Naval veteran Jim Landy lives in Pensacola, Fla., and fights stomach, liver and brain cancer.

“Word leaked out, we heard, that the soil around the facility was contaminated,” Landy said.

10News learned the Department of Veteran Affairs denied medical coverage for some of the veterans who worked at McMurdo Station, including Charlie Swinney.

“Charlie just felt like he got kicked to the curb,” Elaine Swinney said. “He felt like he didn’t count. He felt betrayed.”

“You owe them the truth of what happened,” Vogel said. “Then you deal with the truth from that point forward.”

To see the Navy’s final operating report for the McMurdo Station nuclear power plant click here.

 

Antarctic ice sheet built ‘bottom-up’

By Jonathan Amos, Science correspondent, BBC News. Original article here

Radar image (AGAP)

Radar reveals the ghostly shapes of the Gamburtsevs and the giant freeze-on “beehive” structure above

Scientists have seen once again just how dynamic a place the underside of the Antarctic ice sheet can be.Survey data collected from the middle of the White Continent shows liquid water is being frozen on to the bottom of the sheet in huge quantities.In places, this deeply buried add-on layer is hundreds of metres thick and represents about half of the entire ice column, researchers say.The discovery is reported online in the journal Science.

Project leaders confess to being astonished by the findings.”It’s jaw-dropping, I have to say,” said Professor Robin Bell from Columbia University’s Lamont-Doherty Earth Observatory.”The first time I showed the data to colleagues, there was an audible gasp,” she told BBC News.The new data will add to the understanding of how the ice sheet expands and moves, which in turn will inform researchers as they try to grasp how Antarctica might change in a warmer world.

Twin Otter (M.Studinger)
Twin Otter planes criss-crossed the Antarctic interior with their instruments

The observations come from a major expedition to survey the Gamburtsev mountain range in the polar summer of 2008-2009.Although similar to the European Alps in scale, the Gamburtsevs are hidden under kilometres of ice deep in the Antarctic interior.

“We’ll have to choose a drill site very carefully; we can’t just throw a dart in a board”
Tom Jordan, British Antarctic Survey

An expeditionary team used instrumented planes to gather a wealth of new information about the peaks and their ice shroud. Equipment included radar to see through the ice, showing its many layers, right down to the rock bed. The survey data also gives new insights into how liquid water funnels through the mountains’ valleys.

It is well known that ice sheets grow from the top down, as snow settles on the surface and is compacted over thousands of years. But the new findings illustrate clearly how the sheet can also grow from the bottom up by accumulating layers of liquid water.

Sub-glacial water can be maintained in a liquid state at the bottom of the sheet, either by the intense pressure of the overlying ice or by being in contact with the warmth of the bedrock. But if the water is forced up valley sides to locations of lower pressure, or into ponds in places away from retained heat in rocks, then it will rapidly turn to ice – and can stick to the bottom of the sheet above.

The survey data reveals that this add-on ice makes up 24% of the ice sheet base around Dome A, a 4.2km-high plateau of ice that represents the greatest elevation on the continent. And in some other places, this refreeze phenomenon accounts for slightly more than half of the total ice thickness.

That means in these locations, ice is being created faster on the bottom of the sheet than it is being accumulated through snow deposition on the top.

New dimensions
Liquid water at the base of the sheet has long been recognised to be a “lubricant” for movement, but the latest data adds a whole new dimension to our understanding, said Professor Bell.

“We’ve known there’s been melting under ice sheets from a long time – since the 1960s,” she explained.

“Then it was demonstrated this water could move, it could slosh around; but I think we still had this idea that it just spilled into the ocean.

“Well, now we can show these hydrologic systems are modifying the fundamental stratigraphy of the ice sheet.”

ANTARCTIC GAMBURTSEV PROJECT (AGAP)

Map of Antarctica's Gamburtsev mountains
  • Two camps (N & S) were established deep in the Antarctic interior around the plateau region known as Dome A
  • Aircraft used radar to detect ice thickness and layering, and mapped the shape of the deeply buried bedrock
  • The planes also conducted gravity and magnetic surveys to glean more information about the mountains’ structure
  • By listening to seismic waves passing through the range, scientists could probe rock properties deep in the Earth
  • The Gamburtsev range is totally hidden by ice. In some places that ice covering is more than 4,000m thick
  • A key quest was to find a location to drill ancient ice – ice made from snow that has accumulated over a million years
  • The oldest ice drilled so far comes from a location known as Dome C. It records climate conditions 800,000 years into the past

The discovery also has implications for the search for ancient ice.

Scientists are looking for a location to drill accumulated snow layers, because bubbles trapped in the layers retain information about the climate at the time of precipitation.

Currently, the oldest ice core climate record in the Antarctic extends back about 800,000 years.

Potentially, a core drilled from around Dome A could find ice that was laid down more than a million years ago.

The latest data could have a positive or a negative bearing on that search, said Dr Tom Jordan from the British Antarctic Survey.

“The new process we’re observing suggests old ice could be pushed up towards the surface, which could make this very old ice that would give you a very long climate record much more accessible,” he told BBC News.

“So instead of having to drill a three-kilometre core, the record might have been pushed to within a kilometre of the surface.

“That’s the good news; but it’s balanced against the recognition that in these places where we’ve found these structures, we may also be getting significant melting, deformation and destruction of ice sheet records.

“We’ll have to choose a drill site very carefully; we can’t just throw a dart in a board.”

The Gamburtsev survey was a flagship expedition for International Polar Year (IPY), comprising scientists, engineers, pilots and support staff from the US, the UK, Germany, Australia, China and Japan.

The team established two field camps from which to mount the airborne campaign.

As well as the ice-penetrating radar, other instruments measured the local gravitational and magnetic fields.

Some 120,000km were flown in total, the equivalent of three trips around the globe.

More than 20% of the East Antarctic Ice Sheet was explored.

Jonathan.Amos-INTERNET@bbc.co.uk