Popocatepetl volcano erupting. This volcano (5452 meters elevation) is the second-highest peak in Mexico. It had been dormant for around 60 years when it became active again in 1994. Moderate eruptions and earthquakes have occurred every few months, as of early 2001. As here, these can be accompanied by a column of ash and gas rising for several kilometers into the sky, posing a hazard to aviation. The largest eruption for 1000 years occurred in December 2000. Monitoring of the volcano and evacuation alerts help to protect the surrounding population. Photographed in December 1998.