This is Mount Pinatubo, an active stratovolcano ... to-air missile installations that have since been buried by pyroclastic flows and subsequent lahar. The off-road drive along the O'Donnell ...

Mount Pinatubo, on the Philippine island of Luzon, explodes June 15, 1991, sending more than a cubic mile of volcanic material some 22 miles into the air, while pyroclastic flows bury nearby ...

YAMAGUCHI—An eruption of Mount Aso in Kumamoto Prefecture 90,000 years ago created a pyroclastic flow that traveled 170 kilometers north to the Sabagawa river here, the longest such distance ...