N'Dour gained an international audience in 1994 with his hit song "Seven Seconds," with Neneh Cherry. He went on to earn a Grammy in 2004 for the album Egypt, becoming one of Africa's most influential and popular singers.
Small earthquakes in Ohio and Arkansas associated with hydraulic fracturing for natural gas have taken many people by surprise. Gas industry executives say there's no hard evidence that their activities are causing these quakes. But some scientists say it's certainly possible; in fact, people have been causing quakes for years.
In the 1960s, geologists realized that gold mines in South Africa had created small earthquakes. Caverns dug into the earth thousands of feet below the surface collapsed. The "pancake" effect caused quakes — in one case a magnitude-5.2 temblor.