Underneath old and stable pieces of Earth's crust in North America, the mantle's uppermost portion contains multiple layers that change the velocities of seismic waves.
North America
Posted inResearch Spotlights
Bark Beetles Cause Big Tree Die-Offs, but Streams Flow Steadily
Recent beetle epidemics have driven tree die-offs across North America, and previous studies predicted an increase in annual streamflow would follow—but a new study shows this may not be the case.
Posted inScience Updates
Small Rivers Could Have Big Impact on Arctic Ocean
The Mackenzie River carries the bulk of freshwater flow from North America's tundra to the North Atlantic. But what about the effects of smaller rivers from Canada's Arctic islands?
Posted inNews
Warmer Climate Could Aid Quebec's Wine Industry
By 2050, climate change may make regions of northeastern Canada suitable for growing new varieties of wine grapes.
Posted inResearch Spotlights
Survey Shows Where Arctic Marine Bird Populations Thrive
"Hot spots" of species richness currently include the Bering Sea, Lancaster Sound, Baffin Bay, and Davis Strait. Will this change as sea ice melts?
Posted inResearch Spotlights
Changing Patterns in U.S. Air Quality
Over the northeast United States, ground-level ozone will peak in the winter rather than the summer thanks to continued reductions of regional nitrogen oxide emissions from smokestacks and tailpipes.
Posted inResearch Spotlights
Mantle Below North American Plate Newly Modeled
Data from seismometers spread out across the United States give new clues to the location of structures in the underlying mantle.
Posted inNews
Continuing Bardarbunga Eruption Fuels Scientific Research
How are scientists taking advantage of Iceland’s Bardarbunga eruption, which shows no signs of slowing down?
Posted inNews
Greenland Premier Calls for Balanced Development of Natural Resources
With Greenland confronting environmental and economic challenges, Premier Aleqa Hammond has called for developing natural resources while protecting the environment and dealing with climate change.