Nevado Del Ruiz, Colombia, South America

Type of Volcano:

Nevado del Ruiz is an active Stratovolcano. It is believed to be around 2 million years old.

Structure:

The volcano is 5,321 meters tall (17, 457 ft). It is made of many layers of lava, ash and pyroclastic rocks creating it's cone like shape. This shape formed 150 years ago, when the eruption period of the volcano began. Its top is covered with glaciers but there is significantly less than there once was due to global warming.

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Eruptions:

The volcano usually generates Plinian eruptions, which produce swift-moving currents of hot gas and rock called pyroclastic flows. One of its most dangerous aspects are its lahars and this poses a huge threat to the nearby villages with approximately 500,000 people at risk. Nevado del Ruiz's last eruption took place in 1994.

Location:

Nevado del Ruiz is located in Columbia. It is about 80 miles (129 km) west of Bogotá close to the town of Armero. It is the most active volcano in Colombia.
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Plates:

Nevado del Ruiz is located on the Pacific Ring of Fire, is a part of the Andes mountains, and is the northernmost volcano of the Andean Volcanic Belt in Colombia, South America. Nevado del Ruiz sits on a convergent plate boundary, and was formed by the subduction of the oceanic Nazca Plate beneath the continental South American Plate.
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Nevado Del Ruiz's 1985 eruption:
This was one of Nevado Del Ruiz's most devastating eruptions, killing around 23,000 people.
It was the second most deadly eruption in the 20th century after the 1902 eruption of Mont Pelee on the Caribbean island of Martinique which killed 29,000 people.

Nevado Del Ruiz's 1985 Armero mud flow disaster
In 1985 there was a lahar flowing from Nevado Del Ruiz's summit with an average speed of 60 km per hour, the lahar carried soil, loose rock debris and plants etc. This made the lahar grow as wide as 50 metres in some places. Houses and towns located high enough above river channels escaped damage from the lahars, however within four hours of the eruption, lahars had travelled 100 km and left behind a lot of destruction: more than 23,000 people killed, about 5,000 injured, and more than 5,000 homes destroyed along the Chinchiná, Gualí, and Lagunillas rivers. Hardest hit was the town of Armero at the mouth of the Río Lagunillas canyon. Three quarters of its 28,700 population died.


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Glossary
Stratovolcano- a volcano built up of alternate layers of lava and ash that is a cone like shape.
Pyroclastic Rocks- Clastic rocks composed solely or primarily of volcanic materials.
Glacier- a slowly moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles.
Plinian Eruptions- also known as Vesuvian eruptions, are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in AD 79.
Pyroclastic Flows- a dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing at great speed.
Lahar- a destructive mudflow on the slopes of a volcano.


Extra Facts
Nevado Del Ruiz has had 17 recorded eruptions.
More than 23000 people died in it's 1985 eruption.
Its Latitude is 4.9°N.
Its longitude is 75.32°W.
Nevado del Ruiz covers more 200 sq km.