An Iceberg Caught in the Act of Forming

Article written: 4 Nov , 2011
Updated: 14 Jan , 2016
by

An airborne ‘eye in the sky’ has provided unprecedented views and details of a massive iceberg calving from its parent glacier in Antarctica. Essentially, we’re able to watch the process of an iceberg being born. NASA’s Operation IceBridge mission discovered a huge crack in the Pine Island Glacier in western Antarctica. The mammoth rift extends at least 18 miles and is 50 meters deep, and scientists say it could produce an iceberg more than 800 square kilometers in size.

“We are actually now witnessing how it happens and it’s very exciting for us,” said IceBridge project scientist Michael Studinger, Goddard Space Flight Center, Greenbelt, Md. “It’s part of a natural process but it’s pretty exciting to be here and actually observe it while it happens. To my knowledge, no one has flown a lidar instrument over an actively developing rift such as this.”

The specially outfitted DC-8 airplane for Operation IceBridge flew over the glacier on Oct. 14, 2011 and scientists noticed a crack. They made a special point to return again on Oct. 26 and saw the rift growing.

Pine Island Glacier last calved a significant iceberg in 2001, and some scientists have speculated recently that it was primed to calve again. But until the Oct. 14th flight, no one had seen any evidence of the ice shelf beginning to break apart. Since then, a more detailed look back at satellite imagery seems to show the first signs of the crack in early October.

While Pine Island has scientists’ attention because it is both big and unstable – scientists call it the largest source of uncertainty in global sea level rise projections – the calving underway now is part of a natural process for a glacier that terminates in open water. Gravity pulls the ice in the glacier westward along Antarctica’s Hudson Mountains toward the Amundsen Sea. A floating tongue of ice reaches out 30 miles into the Amundsen beyond the grounding line, the below-sea-level point where the ice shelf locks onto the continental bedrock. As ice pushes toward the sea from the interior, inevitably the ice shelf will crack and send a large iceberg free.

A primary goal of Operation IceBridge is to put the same instruments over the exact same flight lines and satellite tracks, year after year, to gather meaningful and accurate data of how ice sheets and glaciers are changing over time. They will be able to create 3-dimensional maps of the changes taking place.

Below is an animation that shows glacier changes in the highly dynamic Amundsen Embayment of West Antarctica, from satellite and Ice Bridge data.

Scientists know that ice speeds in this area have increased dramatically from the late 1990s to the present as the ice shelves in this area have thinned and the bottom of the ice has lost contact with the bed beneath. As the ice has accelerated, ice upstream of the coast must be stretched more vigorously, causing it to thin.

The changes on Pine Island and Smith glaciers have the potential as continuing sources of ice to the sea, and they have been targeted for repeat measurements in coming years.

Source: NASA

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3 Responses

  1. Anonymous says

    The following is my outrageous message concerning the matter sent to the NASA. I’m not expecting a reply.

    The news about the huge iceberg that will presently break off from Pine Island Glacier must be seen as a chance to test the Iceberg Solution to the water shortages that “global warming” will make inevitable, or the present shortages in places where desalination plants are the only option. Such a test would supplement the theoretical conclusions of a French company arrived at back in the Seventies when Saudi Arabian Prince Mohammed Al Faysal engaged it to study the matter.

    It was reported that a 100-million-ton iceberg covered with a synthetic material to keep it cool, taken from Antarctica to Jeddah, the capital city, by four tugboats would make the more than 7,000-km. journey in six to twelve months.

    Following delivery, the cost of the square meter of fresh water obtained from ice blocks was to be lower than that of desalination using flash distillation. However, several technical problems remained, namely, the possible disintegration of the iceberg along the way, the inadequate depth of the Red Sea and the distribution of water on arrival.

    Once the ice mass has broken off and is adrift, maybe going in the wrong direction, the arrangements will surely be much more difficult. This suggests the urgency of the hour.

    Fortunately there is also a commercial side to the enterprise since it would attract a unique sort of tourism. Many people would want to go along. They would lodge in temporary structures similar to the polar stations or to the buildings in permafrost country. They could bring their own fishing rods with them, or the Travelling-Hotel-On-Ice would supply them at no additional cost, and there would be fishing contests. Passing ships would approach and there would be visits in both directions.

    Furthermore, having finished the trip, others would like to come, take a look and walk around on the ice, and maybe remain there for a few days, along a torrid coastline. On the same day they could take a walk in the desert and then cool off on the ice. Imagine the brochures.

    Once you have made up your collective mind please allow me to book a reservation for a room with a view. However, there are still questions to be answered. Would it rock like a ship? In other words, could one get seasick? Would a big enough substrate remain as steady as “terra firma”? If so, exactly how big would it have to be? The seagulls might already know the answers but as yet there is no access to their knowledge on the subject.

    What about pirates and terrorists? Could they easily clamber aboard? Probably not unless they had mountain-climbing equipment and the proper skills, but never underestimate their ingenuity. Remember the Twin Towers.

    At a time when funds for NASA projects are getting ever more scarce it would also be a much-needed PR campaign. People would be amazed at such a down-to-earth undertaking, coming from such an up-in-the-H clouds outfit. It seems like no list of spinoffs, no matter how long, is enough for many of them. Even worse, at least one of the former is truly revolting: edible toothpaste. (It sounds like a kind of bathroom dessert. With all due respect, only an astronaut would buy and use it.)

    • squidgeny says

      “Following delivery, the cost of the square meter of fresh water obtained from ice blocks was to be lower than that of desalination using flash distillation.”

      I doubt that. This article reports that it would cost $10million to tow a tiny iceberg, which works out at $2500 a litre at point of sale. Scaling it up would not bring the cost down. The strength of ocean currents would be immense. Tourism would not make up for it.

      • Anonymous says

        All right, so forget about the cost, then. Sooner or later it will have to be done, so they might as well start learning how to do it as soon as possible. Quarrels over water rights are already happening, both in the Middle East and the U.S. Besides, Saudi Arabia would be willing and able to collaborate, but the iceberg would have to be parked outside, near the entrance to the Red Sea. Otherwise it would run aground in its shallow waters. My source was the French magazine “La Recherche”, where the matter was discussed in 1976 and once again five years later.

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