A new pollution study in Europe using a van to chase other vehicles and measure their tailpipe emissions finds that newer, diesel-fueled, heavy trucks and buses emit, on average, 34% more of the health and climate hazard known as black carbon than older vehicles of the same types.
Greenland is the land of escaping lakes. In the summer, when soot lands on the ice sheet’s snowy surface and the Sun begins to melt the snow, bright blue lakes form on top of the ice. Just as on land, the water seeks a way down.
Sometimes, instead of carving surface channels, water trickles into the ice sheet through crevasses and vertical shafts called moulins. In the most dramatic cases, a lake can burst through a kilometer-thick ice sheet and rush to the bottom of the glacier in a forceful waterfall. There, under high pressure, water may help the glacier glide a little faster over the rock below.
Just how fast, however, is the subject of an ongoing debate. Continue reading
In July, a helicopter pilot flying over arctic Russia’s Yamal Peninsula noticed an odd sight: a roughly 100-foot-wide crater in the permafrost. Images of the crater went viral online, sparking theories of its formation: Was it a meteorite? A missile strike? A botched alien landing?
When a landslide tore through a remote Alaskan valley in July, no one was there to bear witness. But hours later, geoscientist Colin Stark of the Lamont-Doherty Earth Observatory spotted the event in the pattern of seismic waves passing through the Earth’s crust. Within days, using data from earthquake sensors and satellite images, he and colleague Göran Ekström were able to estimate, from their lab in New York, the landslide’s size, and even determine its path.