A sleeping super-volcano in Germany is showing worrying signs of waking up. It's lurking just 390 miles away underneath the tranquil Laacher See lake near Bonn and is capable of ejecting billions of tons of magma. This monster erupts every 10 to 12,000 years and last went off 12,900 years ago. ... Volcanologists believe that the Laacher See volcano is still active as carbon dioxide is bubbling up to the lake’s surface, which indicates that the magma chamber below is 'degassing'.