Cotopaxi                                            THE DANGER WITHIN




Location and tectonic setting

Cotopaxi is a glacial volcano located about 35 miles south-southeast of Quito, Ecuador.15, 13  For a time, it was considered the highest active volcano in the world, at 5911 meters elevation, or 19,393 feet.2 It is a subduction zone volcano and part of Ecuador's eastern volcanic row, and it has most recently been erupting only andesitic lava, although it has erupted rhyolitic lava in the past.13 It is a stratovolcano, and one of the few glacial volcanoes near the equator.13 It is also part of what is commonly referred to as the Ring of Fire, the chain of subduction zone volcanoes that surrounds the Pacific Ocean.


Latitude: 0.677S  040'38"S
Longitude: 78.436W  7826'10"W 2


Map of Ecuador16

The Volcanic Arc in Ecuador


Cotopaxi as part of the highlands of Ecuador. Other volcanoes within the region include the currently erupting Guagua Pichincha and Tungurahua.17


Subduction zone volcanism:

Subduction zone volcanism occurs when an oceanic plate is pushed under a continental crust; as the oceanic plate, mixed with water and sediment, descends into the earth, it melts and becomes magma, which rises through the continental crust and is erupted, usually explosively, through volcanoes, as seen below. To see a video of this process, visit:


This image was taken from the PowerPoint slides of the infamous Karen Harpp of Colgate University.20 Infamous.


Cotopaxi is one of the many volcanoes in South America that is the result of the Nazca oceanic plate subducting under the South American Plate.24


The earth's tectonic movement22


The Pacific Ring of Fire21



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