This award will support Professor William Rose of Michigan Technological University in a research collaboration with Professor Zoltan de Cserna of the Institute de Geologia of the National Autonomous University (UNAM) of Mexico. The objective of the research is to carry out a detailed study of the later eruptive products of Citlaltepetl volcano, in order to describe its explosivity, sequence of volcanic events and general evolution. The work will result in a modern characterization of a large glaciated sub-tropical strato- volcano, which will facilitate important volcanic hazard evaluations. The analysis of this information will provide important support for the second goal, the establishment of specific volcanic hazard planning for the Citlaltepetl region. Citlaltepetl is the highest peak in Mexico (5675m) and the third highest peak in North America. It is the easternmost volcano of the Transmexican Volcanic Belt, located on an important normal fault zone that marks the central plateau from the Mexican Gulf coastal plains. Citlaltepetl volcano has been proposed for volcanological research because of the perceived potential volcanic hazards for the surrounding areas and because there is only a limited amount of geological or volcanological information available at present. Such a volcano is an important target for detailed study because high, glaciated tropical volcanoes have rarely been thoroughly described and, as the experience at Nevado de Ruiz volcano (colombia) (Naranjo et al., 1986) in 1985 shows, are inadequately understood and particularly dangerous.
