3D Map of Greenland Provides Look into Ice Sheet's Past and Future

A new 3D map of Greenland is providing scientists with the first detailed look of its inner layers, helping to shed some light on the ice sheet's past, as well as open a window into its potentially perilous future in the face of climate change.

The Greenland Ice Sheet is the second largest mass of ice on Earth, an area containing enough water to potentially raise ocean levels a whopping 20 feet.

"This new, huge data volume records how the ice sheet evolved and how it's flowing today," study lead author Joe MacGregor, from the University of Texas at Austin, said in a statement.

For the past two decades, warming temperatures have caused Greenland to melt at unprecedented rates, with scientists just recently reporting that the ice sheet's sub-glacial meltwater lakes are rapidly draining in a matter of just a few weeks. In fact, one of these lakes, which once held 6.7 billion gallons of water, is now completely empty.

It is due to these kinds of factors that sea level rise is currently picking up speed, with its acceleration much larger than scientists previously thought.

So given melting of the Greenland Ice Sheet has potentially dangerous consequences, scientists are studying ice from different climate periods in the past to better understand how the ice sheet might respond in the future.

As described in the Journal of Geophysical Research: Earth Surface, one factor the research team considered in making their new map were ice cores - cylinders of ice drilled from the ice sheet that indicate past snow accumulation and temperatures, and contain impurities such as dust and volcanic ash compacted over hundreds of thousands of years.

MacGregor and his colleagues used ice-penetrating radar to detect these ice cores. This method works by sending radar signals into the ice and recording the strength and return time of reflected signals. Based on the signals, scientists can detect the ice surface, sub-ice bedrock and layers within the ice.

The researchers also relied on radar data collected by NASA's Operation IceBridge and earlier airborne campaigns, which included flights that covered distances of tens of thousands of kilometers across the ice sheet.

Together, these methods provided a unique, comprehensive look of the layers deep inside the Greenland Ice Sheet.

While previous studies were also able to map the ice sheet's internal layers and provide its present thickness, now scientists can map it out on a larger scale much faster, thanks to MacGregor's team. This not only gives the first look into Greenland's past, but hints at what we can expect in the future as the Earth's climate continues to change.

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