***************************************************************** From: John Makario Londono <jmakario@xxxxxxxxx> ***************************************************************** Dear all, This is an unofficial report. On November 20th, Nevado del Huila Volcano erupted. High seismic activity during prior three weeks with more than 9000 earthquakes was recorded in the seismic network for monitoring Nevado del Huila volcano. Many of the earthquakes were associated with small explosions at the submit. On November 20th, at 9:45pm local time, an eruption started, destroying part of a new dome, which was forming during previous months, although visual evidences of it were not available until eruption, due basically to bad weather conditions. Eruption produced melting of a portion of the ice cup covering the volcano. A big mudflow destroyed almost all the bridges around the influence area of the volcano, located across the Paez river. Belalcazar town was the most affected place by the mudflow. Until now, death toll is 10, more than 10 missing persons, and thousands of people lost their properties. Several indigenous groups who lives around the volcano are isolated with no communication. After the eruption, another two mudflows have occurred in the volcano area, but due basically to severe rainy season affecting currently almost all the country. INGEOMINAS (Colombia Geological Survey) through Volcanological and Seismological Observatory of Popayan, alerted people of increasing of volcanic activity since about 1 month ago. Alarms and contingency plans worked very well. Several thousands of people were saved from the eruption, thanks to all the actions and coordination done by all the institutions involved in volcanic hazard relief. On the other hand, on November 9th a seismic swarm was recorded in the seismic network for monitoring Cerro Machin Volcano, at the Volcanological and Seismological Observatory of Manizales, INGEOMINAS. An earthquake with local magnitude 4.6 was felt 100 Km around the volcano, and another two with magnitudes of 2.8 and 2.7 were felt as well. More than 500 earthquakes were recorded in 2 days. Depths of the earthquakes were between 3 and 5 Km, and located to the south and beneath the dome of the volcano. Small cracks were observed at the fumarole field on the top of the dome. After the swarm, the volcano returned to low levels of activity. Around 600 farmers living on the dome slopes and around it were evacuated. Several houses were damaged, but no injured people were reported. For more information in Spanish see Huila volcano: http://intranet.ingeominas.gov.co/popayan/P%C3%A1gina_Principal Machin volcano: http://intranet.ingeominas.gov.co/manizales/P%C3%A1gina_Principal John Makario Londono INGEOMINAS Volcanological and Seismological Observatory of Manizales. Avenida 12 de Octubre # 15-47. Manizales. Colombia Tel. +57-968-843004 Fax. +57-968-843018 http:// <http://intranet.ingeominas.gov.co/manizales/P%C3%A1gina_Principal> www.ingeominas.gov.co ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
