Popocatépetl


Popocatépetl is an active stratovolcano, located in the states of Puebla, Morelos and Mexico, in central Mexico, and lies in the eastern half of the Trans-Mexican volcanic belt. At it is the second highest peak in Mexico, after Citlaltépetl at.
It is linked to the twin volcano of Iztaccihuatl to the north by the high saddle known as the "Paso de Cortés". Izta-Popo Zoquiapan National Park, wherein the two volcanoes are located, is named after them.
Popocatépetl is southeast of Mexico City, from where it can be seen regularly, depending on atmospheric conditions. Until recently, the volcano was one of three tall peaks in Mexico to contain glaciers, the others being Iztaccihuatl and Pico de Orizaba. In the 1990s, the glaciers such as Glaciar Norte greatly decreased in size, partly due to warmer temperatures but largely due to increased volcanic activity. By early 2001, Popocatépetl's glaciers were gone; ice remained on the volcano, but no longer displayed the characteristic features of glaciers such as crevasses.
Lava erupting from Popocatépetl has historically been predominantly andesitic, but it has also erupted large volumes of dacite. Magma produced in the current cycle of activity tends to be a mixture of the two.

Name

The name Popocatépetl comes from the Nahuatl words popōca "it smokes" and tepētl "mountain", meaning Smoking Mountain. The volcano is also referred to by Mexicans as El Popo. The alternate nickname Don Goyo comes from the mountain's association in the lore of the region with San Gregorio, "Goyo" being a nickname-like short form of Gregorio. Legend says that many years ago, a villager met an old man on the slopes of the mountain, who introduced himself as Gregorio Chino Popocatépetl. Gregorio was a personification of the spirit of the volcano, and communicates with the locals to warn them if an eruption is about to happen. Thus, every March 12, the day of San Gregorio, the locals bring flowers and food to the volcano to celebrate the saint.

Geology

The stratovolcano contains a steep-walled, wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris avalanche deposits covering broad areas south of the volcano. The modern volcano was constructed to the south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 AD, have occurred from Popocatépetl since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano.
According to paleomagnetic studies, the volcano is about 730,000 years old. It is cone shaped with a diameter of at its base, with a peak elevation of. The crater is elliptical with an orientation northeast-southwest. The walls of the crater vary from in height. Popocatépetl is currently active after being dormant for about half of last century. Its activity increased in 1991 and smoke has been seen constantly emanating from the crater since 1993. The volcano is monitored by the Deep Earth Carbon Degassing Project.

History

The geological history of Popocatépetl began with the formation of the ancestral volcano Nexpayantla. About 200,000 years ago, Nexpayantla collapsed in an eruption, leaving a caldera, in which the next volcano, known as El Fraile, began to form. Another eruption about 50,000 years ago caused that to collapse, and Popocatépetl rose from that. Around 23,000 years ago, a lateral eruption destroyed the volcano's ancient cone and created an avalanche that reached up to from the summit. The debris field from that is one of four around the volcano, and it is also the youngest.
Three Plinian eruptions are known to have taken place: 3,000 years ago, 2,150 years ago, and 1,100 years ago. The latter two buried the nearby village of Tetimpa, preserving evidence of preclassical culture.
The first known ascent of the volcano was made by an expedition led by Diego de Ordaz in 1519. The early-16th-century monasteries on the slopes of the mountain are a World Heritage Site.

Eruptions

Popocatépetl is one of the most active volcanoes in Mexico and the most famous, having had more than 15 major eruptions since the arrival of the Spanish in 1519.
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