The visuals of water boiling under pits formed on a highway in Veracruz, Mexico, are a result of volcanic activity in Mexico’s Popocatepetl volcanic mountain
Popocatepetl volcano is 5452 m in altitude and capped by glaciers with a long Late Pleistocene-Holocene history. Volcanic activity has been intense during the last 10 000 years. Therefore, the valleys at the NE foothills of the volcano, covered by air-fall ejecta and drained by the runoff of the glaciers, became very attractive to ancient inhabitants of the Xalizintla Valley (XV) west of Puebla City, because of fertility of soils. The XV was occupied by humans about 2000 years ago who witnessed five events related to volcanic activity related to Popo. These events, described in this paper, are being taken into account for volcanic risk evaluation since several towns with a population of more than 23 000 people reoccupied again the Xalizintla Valley.