Sea Ice Images from Spy Satellites Made Public

For the past 10 years, spy satellites have captured super high-resolution images of sea ice at the North and South Poles, but until now, the public –and even most scientists – hasn’t seen them. Finally, hours after a National Academy of Sciences committee recommended that the intelligence community should release the images, they were published by the United States Geological Service.

From Wired:

The new data provides what NAS committee member Thorsten Markus called “a dramatic improvement” in what we can see. The previously off-limits sea ice data has a resolution of one meter. The previous scientific standard sea ice images from the Landsat program have a resolution of 15 meters.

With the new info in hand, scientists should be able to build better models of smaller sea-ice features like melt ponds and ridges. Both are believed to have important roles in sea ice dynamics, but how important they are remains unclear.

It’s not just the high resolution of the satellite data that’s got scientists excited. The intelligence community has also been snapping photos of more locations and for longer than anyone else.

“[The data] is better in quality, it’s longer in duration and it’s broader in coverage,” said Peter Gleick, president of the Pacific Institute, who did not contribute to the new report, but is looking at similar issues for the National Academy of Sciences.

You can view sets of images from a number of locations including the Canadian Arctic, Barrow Alaska and the East Siberian Sea. For each location, there are high quality images from the years 2000, 2001, 2002-2006 and 2007-2008. It’s fascinating stuff.

Hopefully these images will help scientists get more information about how polar sea ice has changed over the past ten years. It will be interesting to see the influence they might have on current global warming science.

Link [Wired]

Ice Bridge Holding Wilkins Ice Shelf Breaks Up

It’s only a matter of time before we’ll be saying RIP, Wilkins Ice Shelf. The ever-shrinking Antarctic ice shelf had been held together by an ice bridge that has now collapsed, increasing concern over how fast global warming is affecting the area. A satellite photo from the European Space Agency showed that the 40km bridge splintered at its narrowest point, which was about 500 feet across.

David Vaughan, a glaciologist with the British Antarctic Survey, says change in the Antarctic is rearely so dramatic.

From Reuters:

The Wilkins, now the size of Jamaica or the U.S. state of Connecticut, is one of 10 shelves to have shrunk or collapsed in recent years on the Antarctic Peninsula, where temperatures have risen in recent decades apparently because of global warming.

The loss of the ice bridge, jutting about 20 meters out of the water and which was almost 100 km wide in 1950, may now allow ocean currents to wash away far more of the Wilkins shelf.

“My feeling is that we will lose more of the ice, but there will be a remnant to the south,” said Vaughan. Ice shelves float on the water, formed by ice spilling off Antarctica, and can be hundreds of meters thick.

The Antarctic is changing rapidly, to the extent that scientists – including those involved in a new study conducted by the US Geological Survey and British Antarctic Survey – widely regard the incredibly fast transformation of the map area to be among the most “profound, unambiguous examples of global warming on Earth”.

And yet there are still people out there who don’t believe climate change is a threat. They also believe that the Earth is flat, Bigfoot lives in their backyard, Elvis and Tupac are hanging out drinking daquiries somewhere in South America, Britney Spears sings live at all her concerts and the moon landing was taped by Steven Spielberg in a studio lot in California.

Link [Reuters]
Photo credit: REUTERS/Alister Doyle

Antarctic Ice Shelf About to Collapse Due to Global Warming

Just a small sliver of ice is holding a giant Antarctic ice shelf in place, with experts saying that it will collapse any time now. The Wilkins Ice Shelf is the latest victim of global warming, set to join nine other shelves that already have been be lost around the Antarctic peninsula in the past 50 years.

From Reuters:

“We’ve come to the Wilkins Ice Shelf to see its final death throes,” David Vaughan, a glaciologist at the British Antarctic Survey (BAS), told Reuters after the first — and probably last — plane landed near the narrowest part of the ice.

The flat-topped shelf has an area of thousands of square kilometers, jutting 20 meters (65 ft) out of the sea off the Antarctic Peninsula.

But it is held together only by an ever-thinning 40-km (25-mile) strip of ice that has eroded to an hour-glass shape just 500 meters wide at its narrowest.

In 1950, the strip was almost 100 km wide.

“It really could go at any minute,” Vaughan said on slushy snow in bright sunshine beside a red Twin Otter plane that landed on skis. He added that the ice bridge could linger weeks or months.

Temperatures on the Antarctic Peninsula have warmed by 3 degrees Celcius since 1950, the fastest rise in the Southern Hemisphere. Though loss of ice shelves does not in itself raise sea levels since the ice is floating and already mostly submerged, it could allow ice sheets on land to move faster, which would add extra water to the seas.

The U.N. Climate Panel projected in 2007 that world sea levels were likely to rise between 18cm and 59cm this century, but that doesn’t even take Antarctica ice shelf loss into consideration. Even a small change in the rate of ice shelf loss could affect sea levels, and Antarctica’s ice sheets contain enough water to raise world sea levels by 57 meters.

Link [Reuters]

Head For the Hills, Stock Up The Larder, And Git Yer Guns Loaded, Another Huge Antarctic Ice Shelf has Collapsed

Stock up the foot, clean the guns, and get your waders on- the collapse of the Antarctic ice shelf is in high gear. The Wilkins ice shelf, an area 160 square miles large, seven times the size of Manhattan, has suddenly collapsed. Scientists had the rare opportunity to film the collapse when they saw it happening over satellite images and diverted more lenses to cover it, even getting an airplane in the air to shoot video and photos.

There are two kinds of polar ice- sea ice and land ice (not the scientific names, but they’ll do here). The sea ice sits in the ocean, most of it sitting below water level. When those ice shelfs break off they don’t have much of an impact on sea levels. When the land ice- the glaciers sitting on the ground above sea level- collapses, it adds new mass into the ocean and can quickly raise sea levels across the globe.

The Antarctic land ice is being held back by the now quickly collapsing sea ice. As the world’s temperature rises snow and ice melt and run down to the ground through the glacier in giant ice tunnels. The water follows the slope of the land down to the ocean and acts like a lubricant between the ground and the glacier ice above. When the sea ice has collapsed enough not to hold up the lubricated land ice, it can all fall apart in a matter of hours and days.

How do you think the world would react to a 20 foot rise in sea levels over the course of a day? It’d be pure chaos and madness, epic disaster movie style.

Someone smarter than me has put together a Google Maps mashup that will show you what rising sea levels look like on a map of the world meter by meter. See for yourself. New York City would be really screwed.

The future will be nothing if not interesting.

Links [Huffington Post] & [The National Snow and Ice Data Center] & [The British Antarctic Survey]