Location and setting: Mexico; central Mexican Volcanic Belt, complex tectonic setting of continental arc and back-arc
Background information: located in densely populated region with over 20 million people; wide range of eruption styles, including Plinian events; reawakened in 1994 after almost 70 years of quiescence; alternation between lava dome growth-and-destruction episodes, and moderately explosive activity separated by long periods of almost total quiescence; currently one of the largest passive producers of SO2 worldwide.
Relevance to project: volcano-tectonic seismicity preceding reawakening shows precursory activity that may be characteristic of reawakening after a long period of quiescence for polygenetic volcanoes; explosions are usually preceded by a diversity of precursors; however, the nature and significance of precursors changed and evolved during the 15 years of activity making their recognition a complex process; translating the interpretations of the observed signals into alert levels is a major issue in risk management; case for hindsight evaluation of unrest periods; potential for catastrophic impact on society and infrastructure
Monitoring data available to consortium: 1989-present: seismic records including short-band and broadband; 1994-1996: tiltmeter records; 1994-present: Daily reports of activity and events. Includes a large dataset of images obtained with monitoring cameras (visible and one thermal IR camera); 1995-present. Hydrogeochemical sampling and analysis of water springs around the volcano (about 4 times a year); 1995-present. Periodic measurements of deformation on the north flank of the volcano using an EDM station; 1995-present. Sporadic vertical photogrammetric photographs of the crater that have been used to estimate volumes of emplaced domes.
Summary of the Popocatépetl Situation
(adapted from DE LA CRUZ-REYNA S., TILLING R.I. (2008) Scientific and public responses to the ongoing volcanic crisis at Popocatépetl Volcano, Mexico: importance of an effective hazards-warning system. J. .Volcanol. Geotherm. Res. 170 (1-2):121-134 (doi:10.1016/j.jvolgeores.2007.09.002)
Popocatépetl Volcano is located in the central Mexican Volcanic Belt, within a densely populated region, with over 20 million people vulnerable to direct hazards associated with a major explosive eruption. Situated about 70 km southeast of downtown Mexico City, Popocatépetl is arguably the most dangerous volcano in the country. This 5454-m-high volcano’s geologic past clearly indicates that it is capable of producing catastrophic eruptions: three Plinian events have occurred within the past 5000 years B.P., well within the period of human settlement in central Mexico (Siebe et al., 1996; Siebe and Macías, 2004). Fortunately, to date the current eruptive episode—beginning in December 1994 after being dormant for nearly six decades—has consisted of relatively minor activity, which has characterized Popocatépetl’s activity since the 14th century (De la Cruz-Reyna et al., 1995). Nonetheless, given the huge population potentially at risk, together with concerns about possible escalation of eruptive activity, the management of the ongoing “volcanic crisis” at Popocatépetl (CENAPRED-UNAM, 1995) has posed, and continues to pose, a major challenge for volcanologists, national and local civil authorities, and the affected public.
The official body in charge of the risk management (including volcano monitoring) at the federal level is the National System of Civil Protection (SINAPROC) which is part of the Ministry of the Interior (Secretaría de Gobernación) at a level equivalent to an undersecretary of state. The Coordination is supported by two main bodies: The National Direction of Civil Protection, an operational body in charge of implementing the preventive, and relief actions, and the National Center for Disaster Prevention (CENAPRED), a technical body whose objectives are to promote the applications of technology for the prevention and mitigation of disasters, to train and inform professionals and technicians on these subjects, and to disseminate the necessary information for preparedness and self-protection to all the people exposed to a hazardous phenomena, and to maintain the volcano monitoring in collaboration with the UNAM, and other national and international organizations.