Political and scientific uncertainties in volcanic risk management: The yellow alert in Quito in October 1998

Volcanic risk management involves volcanologists, civil authorities and the affected population. The paper reports on one `yellow alert' in Quito in 1998. It describes the scientific context, the political announcement and the decision-making process that preceded, as well as the social perception of the volcanic crisis. This revised version was published online in July 2006 with corrections to the Cover Date.