Colima (volcano)
2007 Schools Wikipedia Selection. Related subjects: Central & South American Geography
| Colima | |
|---|---|
 Colima's volcano as seen by the Landsat satellite |
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| Elevation | 4,330 metres (14,206 feet) |
| Location | Jalisco, Mexico |
| Range | Eje Volcánico Transversal |
| Coordinates | |
| Type | Stratovolcano |
| Age of rock | 5 million years |
| Last eruption | ongoing |
Colima's Volcano is the most active volcano in Mexico, and has erupted more than 40 times since 1576.
Despite its name, only a fraction of the volcano's surface area is contained within the state of Colima; the majority of its surface area lies just over the border in the neighboring state of Jalisco, toward the western end of the Eje Volcánico Transversal mountain range. It is about 300 miles (485 kilometres) west of Mexico City and 75 miles (125 km) south of Guadalajara, Jalisco.
There are actually two peaks in the volcano complex: Nevado de Colima (4330 m), which is older and inactive, lies about 5km north of the younger and very active 3860m-tall Volcán de Colima (also called Volcán de Fuego de Colima). Since 1869-1878, a parasitic set of domes, collectively known as el Volcancito, have formed on the northeast flank of the main cone of Colima's volcano .
Geological history
Colima's volcano has been the site of volcanic activity for about 5 million years. In the late Pleistocene era, a huge landslide occurred at the mountain, with approximately 25 km³ of debris travelling some 120 km, reaching the Pacific Ocean. An area of some 2,200 km² was covered in landslide deposits. Massive collapse events seem to recur at Colima's volcano every few thousand years.
The currently active cone is situated within a large caldera that was probably formed by a combination of landslides and large eruptions. About 300,000 people live within 40 km of the volcano, and in light of its history of large eruptions and situation in a densely populated area, it has been designated a Decade Volcano, singling it out for particular study.
Current activity
In recent years there have been frequent temporary evacuations of nearby villagers due to threatening volcanic activity. Eruptions have occurred in 1991, 1998-1999 and from 2001 to the present day, with activity being characterised by extrusion of viscous lava forming a lava dome, and occasional larger explosions, forming pyroclastic flows and dusting the areas surrounding the volcano with ash and tephra.
The largest eruption for several years occurred on 24 May 2005. An ash cloud rose to over 3 km over the volcano, and satellite monitoring indicated that the cloud spread over an area extending 110 nautical miles west of the volcano in the hours after the eruption . Pyroclastic flows travelled 4-5 km from the vent, and lava bombs landed 3–4 km away. Authorities set up an exclusion zone within 6.5 km of the summit.
On June 7, 2005, Colima's volcano erupted again in its largest recorded eruption in several decades. Plumes from this eruption reached heights of 5 km (>3 miles) above the crater rim, prompting the evacuation of at least three neighboring villages.