Satellite data suggest a volcano in Tanzania that expels extremely runny lava could be creeping toward an eruption.

When a volcano is about to erupt, the surrounding land puffs up like a squeezed balloon. The technical term is "transient deformation," and Virginia Tech researchers have detected and tracked this short-lived movement for the first time using satellite observations of Ol Doinyo Lengai,

Scientists have observed land surrounding a "unique" volcano in Tanzania bulging, a sign that a massive reservoir of magma is puffing up the surrounding areas like a balloon — and possibly an impending eruption.