As climate warms, the Greenland ice sheet is melting, helping to fuel global sea-level rise. Follow a small team of scientists as they hike onto the sheet to investigate the forces large and small that are demolishing the ice. (All photos: Kevin Krajick) READ THE FULL SCIENTIFIC STORY AND SEE A VIDEO
In summer, much of the ice sheet starts melting from the top down, lacing the surface with ephemeral streams. Near the edge of the Russell Glacier, scientists navigate through runoff.
Edge of the ice along the Akuliarusiarsuup River, which carries meltwater toward the sea. The road alongside leads to the small town of Kangerlussuaq.
The team crosses from land to ice. Debris in foreground is part of the glacier’s terminal moraine, left behind by receding ice.
Glaciologist Marco Tedesco of Lamont-Doherty Earth Observatory (left) and UCLA PhD. student Matthew Cooper survey the ice’s lower edges, where dirt and tiny organisms are most concentrated. Their dark colors increase absorption of solar energy, and thus hasten melting.
Further out, the ice lightens progressively.
The ice slopes upward, devolving into hills, hummocks, gullies and crevasses.
Meltwater ponds are underlain by dense blue ice–once buried and highly compressed, over hundreds or thousands of years. Now, it is exposed to the sun.
Tedesco inspects a small crevasse, into which a nearby meltwater stream is disappearing.
The team selects a study site pocked with cryoconites—circular holes filled with water, whose shallow bottoms harbor dust, soot and microorganisms. They are small but probably powerful engines of melting.
Baby cryoconites, which may grow larger as the season progresses.
Tedesco measures a larger cryoconite. The water will be sampled for later chemical and biological analysis.
A group of cryoconites has evolved into a pond. Cooper samples bottom muck, which may include algae, bacteria, protozoa and tiny crab-like creatures.
Tedesco and Lamont-Doherty advisory board member Daniel Bennett (left) measure the intensity and spectra of sunlight reflected off the surface.
A camera-equipped drone is used to map the area.
Bennett retrieves the ice capping one small melt pool. Organisms produce gases that may bubble up and get trapped under such caps.
In a canyon maybe 100 feet deep, a meltwater river flows.
The river, about 15 feet wide at this point, plunges through a moulin, into an under-ice plumbing system. Among other questions: how much of this water is retained within the ice, and how much reaches the ocean?
Water pours from the ice edge into the Akuliarusiarsuup River.
Tundra flowers bloom several miles from the ice front. In some areas, warming climate is causing shrubs and even trees to replace Arctic vegetation.
Off the ice, one result of warm summers: overwhelming swarms of mosquitoes. Cooper wears protection.
In a protected spot, a few trees sprout—a new phenomenon here.
The river empties into a fjord that connects to the ocean. The settlement of Kangerlussuaq (in Greenlandic, Big Fjord) lies in the distance to the right.
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Jane O'Grady
8 years ago
Thank you very much for the images I received of the Greenland ice sheet. They are very descriptive of why we need to act immediately to counteract global warming as much as possible. Keep up your good work.
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Thank you very much for the images I received of the Greenland ice sheet. They are very descriptive of why we need to act immediately to counteract global warming as much as possible. Keep up your good work.