In April, 2012, Popocatépetl, a glacier-clad stratovolcano sitting 70 km (43.5 miles) southeast of Mexico City, once again dramatically lived up to its Aztec name “smoking mountain” by ejecting smoke, gas and ash up to 1.5 kilometers in the air. At times, incandescent blocks were tossed as far as 500- 800 km (300- 497 mi) from the rim, and plumes of ash drifted over villages and towns to the east.
The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite captured this true-color image on April 20, at 16:45 UTC (11:45 a.m. local time). In this image, a large cloud of gray ash and smoke can be seen rising from the caldera of Popocatépetl and blowing generally to the east. Where cross winds blow, some of the ash is driven to the northeast.
Mexico City, the capital city and home to over 8.8 million people, lies to the northwest of Popocatépetl, in the Valley of Mexico. It can be visualized as a large gray smudge. Puebla, the fourth largest city in Mexico, lies under the ash plume to the east of the volcano. Ashfall has been reported in Puebla on several days in April. On April 17, it was reported that the governor of Puebla asked to suspend classes in the schools of the communities near the volcano, due to the ashfall and the increased volcanic activity. On that same day the National Center for Disaster Prevention (CENAPRED) raised the alert level from Yellow Phase Two to Phase Three and prepared shelters and evacuation routes, to be used if the eruptions became more dangerous.
On April 20, the day this image was captured, the Associated Press reported that residents of Xalitzintla, a town near the volcano’s base, were awakened by a window-rattling series of eruptions from the volcano. Mexico’s National Disaster Prevention Center confirmed the increased activity , reporting that eruptions began at 5:05 a.m. local time (10:05 UTC) on that day, with 12 eruptions occurred within two hours.