In our warming world, Greenland's glaciers are melting at an alarming rate. Recently, NASA scientists announced that one of the continent's major northern glaciers, ZachariaeIsstrom, is entering an accelerated rate of retreat after millennia of glacial stability. It's a big glacier, and a big deal since it contains 5 percent of Greenland's ice sheets.
Josh Willis is principal investigator of NASA's Oceans Melting Greenland program. He explained what "OMG" means to him.
Josh Willis: “OMG” to me is Oceans Melting Greenland. Our project is designed to look at the oceans around Greenland to try and figure out just how much of the ice is being melted away, because it's in contact with the warm water. And most people when they hear that they go, “Oh my god.”
Dave Schlom: What exactly is the mechanism going on here — why are the oceans are contributing to the so much?
JW: Well, it's connected to the melting at the surface in fact. What happens is, Greenland melts at the surface but it doesn't run off the top. Actually, the melt water runs down underneath the glaciers and comes out right at the bottom. When that happens, it rises at the ocean surface because a lot of these glaciers sit right in the water. And when it does, it pulls warm water in towards the glacier. So the combination of melting at the surface, and the fact that these glaciers empty right into the ocean, means that they can pull warm water in and melt the edges even faster.
DS: How do you go about studying this process? What kind of field work and observations are you doing?
JW: Well we've developed a five-year mission called OMG to measure both the ice, right at the edges where it thins and retreats, and then also measure the temperature and salinity of the oceans nearby. So by looking at both together, we hope that we can get a better feel on just how much the oceans are responsible for melting the ice.
What kinds of impact could this have on the ocean currents there in the Atlantic and sea level?
JW: Well, because the ocean currents are intimately involved in the melting, more melting could actually bring more melting — because the runoff from the top of the glacier, literally pulls in the warm water off the shelf and out of the deep ocean to melt away even more at the edges. So we could be looking at a kind of runaway process that could go on indefinitely even if we stop warming the planet.
DS: What got you personally interested in studying this project.
JW: Well, I study sea level rise. To me, that's one of the most important indicators that people of the planet are changing our climate. And it's also a huge impact. And if you want to understand sea level rise, then Greenland and the huge ice sheet in the Antarctic are the places to be.
DS: That's NASA oceanographer Josh Willis, principal investigator for O.M.G., Oceans melting Greenland. The report is a production of North State Public Radio. Follow us on Twitter @nsprnews and @daveschlom.
