Archive for Friday, November 4, 2011

Scientists hope to see birth of iceberg

November 4, 2011

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Radar technology developed at Kansas University is helping NASA scientists track something they’ve never monitored before: the birth of an iceberg.

Last month, a crew flying over Antarctica as part of NASA’s Operation IceBridge discovered an 18-mile-long crack in the ice shelf of the Pine Island Glacier. The crack was 240 feet wide and almost 200 feet deep.

In coming weeks or months, scientists expect that crack to grow until an iceberg as large as 310 square miles falls into the ocean.

This is the first time that scientists have been able to do a detailed survey on an actively forming iceberg. Part of the technology being used to collect data has been developed at KU’s Center for Remote Sensing of Ice Sheets. Aboard the DC-8 aircraft that is flying over the crack is KU’s radar equipment that can measure the thickness of the ice sheet from the top to the bedrock. Helping operate the equipment are a trio of KU researchers.

“They have known these things happen to ice shelves and they’ve seen it before. But being there and seeing it starting to happen, it’s cool,” said Carl Leuschen, the deputy director of CReSIS.

The formation of the iceberg is part of the ice sheet’s natural cycle. About once every decade, icebergs of this size and shape form. The last major iceberg from the glacier occurred in 2001.

“We are pretty excited to have been there and to have really observed this firsthand how it happens,” IceBridge Project Scientist Michael Studinger said during an international conference call Thursday afternoon.

Right now, scientists aren’t linking the creation of this iceberg to climate change. But if the frequency of icebergs increases, it could indicate a change in the system and a response to warming water.

Of particular interest is the tip of the rift where the crack pushes forward at about two meters per day. How the crack in the ice sheet grows is a process that NASA scientists would like to better understand. Ultimately, it could help scientists create more-accurate models on future shrinking or expanding ice sheets around the world.

Based out of Punta Arenas, Chile, Operation IceBridge is in its third year. During October and November, crews make 11- to 12-hour flights over Antarctica to gather data. Planes fly, usually as low as 1,500 feet, over the same path year after to year to gauge how much the ice sheets have changed.

During the flight mission, a KU researcher is on board operating the radar equipment. The three KU researchers are expected to return to KU before Thanksgiving.

“It is a lot of work to go down there and manage the system and the amount of data you get and making sure it is processed correctly. But they are having fun down there,” Leuschen said.

Along with KU’s radar equipment, the planes gather information with a digital mapping system, laser altimeters and a gravimeter.

NASA’s Operation IceBridge is helping gather data on ice sheets in between the time that the Ice Climate and Elevation Satellite stopped operating in 2009 and before the replacement satellite is launched in 2016.

“It’s based on the desire to avoid an ‘Oh my God’ moment in 2016 when (the satellite) launches and begins to gather data,” Studinger said.

The Pine Island Glacier is one of the largest and fastest-moving ice sheets in the world. It’s also a rapidly thinning glacier. According to Studinger, the glacier is a particularly sensitive area because much of the land on where the ice sheet sits is well below sea level. The ice is melting at a rate of several meters per year and could be increasing.

“Because of sensitivity to climate change, the Pine Island Glacier is referred to as the big underbelly of Antarctica,” Studinger said.

Reporter Christine Metz can be reached at 832-6352. Follow her at Twitter.com/SFHorizons.

Comments

Carol Bowen 3 years, 9 months ago

Locally, this means more drastic and unpredictable weather. As we getter warmer, we are seeing more fire ants and armadillos. Crops are having a rough time.

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