A "zombie" volcano in Bolivia has been rumbling in its sleep — despite being dormant for hundreds of thousands of years — and scientists now think they know why.
Uturuncu, located in the Andes in southwestern Bolivia, last erupted around 250,000 years ago. For several decades, it has been showing signs of unrest, releasing plumes of gas, shaking with earthquakes, and causing the surrounding ground to deform, leading to concerns it could be about to erupt.
