Two volcanic crises in Ecuador beginning in September 1999 presented serious challenges to scientists monitoring them and to many of thousands of people living nearby. Eruptive activity at Volcán Guagua Pichincha, just west of the capital city of Quito (pop. 1.8 million), increased significantly in mid 1999, and Volcán Tungurahua (about 100 km south of Quito) began to erupt in mid-September (map). By early October, both volcanoes were erupting, and explosions, ashfalls, and mudflows began to affect areas nearby and downwind. Volcan Guagua Pinchincha Oct. 7, 1999 Tungurahua Volcano Nov. 2, 1999

This volcanic activity considerably disrupted the daily lives of people living around the volcanoes. Lahars made roads impassable and nearly 25,000 people were evacuated from villages on the flanks of Tungurahua. Occasional ash fall in Quito has led officials to close schools and the Quito International Airport several times.

In response to an official request in mid-1999 from the Government of Ecuador, the USGS provided technical assistance, monitoring equipment, and consultation to the Instituto Geofísico of the Escuela Politécnica Nacional to monitor the two volcanoes and to assess volcanic hazards. Through the end of the year, many USGS scientists worked in two- to three-week-long shifts in Ecuador to work with Ecuadorean scientists and to provide advice about volcanic unrest and eruptive activity to the US Embassy, USAID staff in Ecuador, and representatives of various international agencies responding to the crises.

During the past decade, the USGS has provided the Instituto Geofísico with volcano-monitoring equipment, including telemetered seismometers, tiltmeters, acoustic flow monitors, and base station computer networks. We have also provided training and in-country assistance to install and operate their country-wide volcano monitoring network.

As one or both of these volcanoes may continue to be active for many months, the exact nature of future assistance will depend upon the volcanic activity and the specific needs of the Ecuadorean scientists.

Information About Volcanoes in Ecuador

• Volcan Guagua Pinchincha
  Tungurahua Volcano
  Summaries of activity available from the Smithsonian Institution's Global Volcanism Program, in English
• Instituto Geofísico, Sismología y Vulcanología
  Home page of the scientific agency responsible for monitoring Ecuador's volcanoes, in Spanish, including monitoring data, updates, and photographs.