Columbia University

When the Sahara turned to sand

The Sahara wasn't always a desert. Trees and grasslands dominated the landscape from roughly 10,000 years ago to 5,000 years ago. Then, abruptly, the climate changed, and north Africa began to dry out.

dateNov 11, 2013 in Earth Sciences
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New techniques produce cleanest graphene yet

Columbia Engineering researchers have experimentally demonstrated for the first time that it is possible to electrically contact an atomically thin two-dimensional (2D) material only along its one-dimensional ...

dateOct 31, 2013 in Nanomaterials
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Pumping draws arsenic toward a big-city aquifer

Naturally occurring arsenic pollutes wells across the world, especially in south and southeast Asia, where an estimated 100 million people are exposed to levels that can cause heart, liver and kidney problems, ...

dateSep 11, 2013 in Environment
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Tackling an Ice Age mystery

In the northern hemisphere, ice sheets ebb and flow in 100,000-year cycles, driven by varying amounts of sunlight falling on Earth's surface as its orbit and orientation toward the sun changes. But astronomical variations ...

dateSep 05, 2013 in Earth Sciences
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