New breakthroughs in the study of glacial meltwater

Today’s Image Of The Day features glacial meltwater from a Greenland ice sheet traveling down through cracks of the glacier.

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Today’s Image Of The Day features glacial meltwater from a Greenland ice sheet traveling down through cracks of the glacier. When temperatures warm during the summertime, the top layers of ice begin to melt, forming pools of water that can slide down such cracks and reach the bedrock. Once at the bottom, the water creates a slippery slide for the glacier to glide on.

A team of researchers from Columbia University has created a new technique that allows what happens to meltwater once it reaches the bottom. Upon completing preliminary trials, the team published their results in the journal Geophysical Research Letters.

According to the study, the outcome of meltwater movement depends on the rate at which meltwater flows down, along with the amount of water stored beneath the ice in the winter. The permeability and topography of the land also play an important role.

“The distribution of meltwater evolves constantly, switching from one location to another,” said Columbia grad student Winnie Chu, lead author of the study. “By knowing how this distribution changes seasonally, we can better understand the spatial linkage between ice and water flow.”

According to Chu, when ice melts in the summertime, much of that water can be stored at the base of the glacier. This storage space of subglacial water could ultimately mediate some of the impact of meltwater on summer ice flow. The new technique is a massive breakthrough in the study of the lifespan of meltwater.

Joseph MacGregor, glaciologist and geophysicist at the NASA-Goddard Space Flight Center, commented, “We have prevailing ideas of how water flows on the surface of ice sheets, through ice sheets, and under ice sheets. What we don’t have are great observations of where that water is beneath the ice most of the time. This result changes that state of affairs. It also demonstrates the value of airborne remote sensing for testing fundamental glaciological hypotheses.”

Credit: Marco Tedesco from the Lamont-Doherty Earth Observatory