As is the case for many subduction-zone volcanoes, Nevado del Ruiz can generate explosive Plinian eruptions with associated pyroclastic flows that can melt snow and glaciers near the summit, producing large and sometimes devastating lahars (mud and debris flows). The Andean Volcanic Belt is produced by the eastward subduction of the oceanic Nazca Plate beneath the South American continental plate. It is the third most northernly of the volcanoes lying in the North Volcanic Zone of the Andean Volcanic Belt, which contains 75 of the 204 Holocene-age volcanoes in South America. Nevado del Ruiz lies within the Pacific Ring of Fire, a region that encircles the Pacific Ocean and contains some of the world's most active volcanoes. The massif is located at the intersection of four faults, some of which are still active. The volcano is part of the Ruiz–Tolima volcanic massif (or Cordillera Central), a group of five ice-capped volcanoes which also includes the Tolima, Santa Isabel, Quindio and Machin volcanoes. Nevado del Ruiz, which lies about 129 km (80 mi) west of Bogotá, is part of the Andes mountain range. Today, the Nevado del Ruiz volcano is constantly monitored by the Volcanic and Seismic Observatory of Manizales. The volcano continues to pose a threat to the nearby towns and villages, and it is estimated that up to 500,000 people could be at risk from lahars from future eruptions. The summit of Nevado del Ruiz is covered by large glaciers. The volcano is part of Los Nevados National Natural Park, which also contains several other volcanoes. Similar but less deadly incidents occurred in 15, consisting of a small explosive eruption followed by a large lahar. This event later became known as the Armero tragedy-the deadliest lahar in recorded history. On November 13, 1985, a small eruption produced an enormous lahar that buried and destroyed the town of Armero in Tolima, causing an estimated 25,000 deaths. The impact of such an eruption is increased as the hot gas and lava melt the mountain's snowcap, adding large quantities of water to the flow. These eruptions often cause massive lahars (mud and debris flows), which pose a threat to human life and the environment. The volcano usually generates Vulcanian to Plinian eruptions, which produce swift-moving currents of hot gas and rock called pyroclastic flows. The current volcanic cone formed during the present eruptive period, which began 150,000 years ago. Volcanic activity at Nevado del Ruiz began about two million years ago, since the Early Pleistocene or Late Pliocene, with three major eruptive periods. It is a stratovolcano composed of many layers of lava alternating with hardened volcanic ash and other pyroclastic rocks. Nevado del Ruiz ( Spanish pronunciation: ), also known as La Mesa de Herveo (English: Mesa of Herveo, the name of the nearby town) is a volcano on the border of the departments of Caldas and Tolima in Colombia, about 129 km (80 mi) west of the capital city Bogotá.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |