An Inland Connection?

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From: Kathryn Hansen, NASA’s Earth Science News Team/Cryosphere Outreach Specialist

Scientists have long been tracking Greenland’s outlet glaciers, yet aspects of glacier dynamics remain a mystery. One school of thought was that glaciers react to local forces, such as the shape of the terrain below. Then, researchers noticed that glaciers in different regions were all thinning together, implying a connection beyond local influences. Scientists have posed theories about what that connection might be, but the jury is still out.

Recently, the landscape in southeast Greenland has started to change. Helheim Glacer, which was thinning at 20-40 meters per year, slowed dramatically to just 3 meters per year while thinning of the nearby Kangerdlugsuaq also slowed. Further south, two neighboring glaciers showed the opposite trend and started thickening by as much as 14 meters per year. Neighboring glaciers behaving in similar ways implies a connection, but what exactly?

The IceBridge flight on May 12 will help scientists learn how changes to outlet glaciers affect the ice sheet inland. Instruments on the P-3 surveyed in detail three southeast glaciers: Fridtjof-Nansen, Mogens North and Mogens South. Next they flew four long lines mapping changes near the ocean and up to 60 kilometers inland, capturing the extent, if any, at which thinning near coast reflects on changes to the ice inland. It’s an important connection to make; while the loss of outlet glaciers alone would not contribute much to sea level rise, loss of the ice sheet could have a dramatic impact.

IceBridge crew and researchers board the P-3 on May 12 for a flight to study glaciers and the ice sheet in southeast Greenland. Credit: NASA/Kathryn Hansen

The P-3 flew over areas of sea ice wile mapping glaciers and the flight line closets to the coast. Credit: NASA/Kathryn Hansen

Mountainous terrain along Greenland’s southeast coast led to short-lived periods of turbulence and spectacular scenery. Credit: NASA/Kathryn Hansen