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Mexican Volcanic Zone, Mexico
Volcanos ash deposits, faults

Significance: Volcanic and seismic activities in the Mexican Volcanic zone (also know as the Neovolcanic Plateau) are particularly significant because the region is accessible to North American Scientists.  Investigators can make comparison studies using Earth orbit based photography and field work.  As the cultural and historical center of Mexico, the region is characterized by a high population density and extensive economic investments which could be serious impaired by geologic disasters.  This was evidenced by the devastating Mexico City earthquake which affected much of this area in September 1985.  Volcanoes Jorullo and Paricutin, cinder cones located in the southwest, have erupted in recent times.  Several times, crews have photographed plumes emanating from the summit of Colima, which is frequently active.  In December 1994, Popocatepetl, the large volcano between Mexico City and Puebla, erupted.  This region surrounding "Popo" includes roughly 40 million people.

Physical Characteristics: Numerous volcanos, many extinct and in various stages of erosion, rise over ash-filled basins.  These relatively large, level basins at an average altitude of 2400 meters, have fertile volcanic soils.  A chain of  imposing volcanoes - Colima, Tancitaro, Tuluca, Popocatepetl, Malinche, Orizaba and Cofre de Perote - dominate the landscape.  Rivers are few as volcanism played havoc with the drainage of the plateau.  As a result, several large lakes, Chapala, Patzcuaro, and Texcoco among others, were formed.  The origin of the volcanic belt is a deep-seated shear zone which developed tension fractures.
Near both coasts, the plateau falls off steeply to sea level.  Detached from the volcanic plateau and at a much lower elevation are the volcanoes of the Tuxtlas.

Observationa Techniques: Vertical stereo views of the volcanoes using the 250 mm lens will be most useful.  Simultaneous photography using the 100 mm lens will provide a regional perspective and document seasonal and long-term changes in vegetation.

[[Image]]

Index map of Mexico, showing sites of volcanic activity until 1995.


Center Point: 18.5°N, 101°W
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