Abstract:
In Nicaragua numerous active volcanoes generate high levels of volcanic hazard. The capital, Managua, is situated in the axis of the volcanic chain; volcanic structures can be found in the centre of the city and active volcanoes are situated in distances of 10 to 20 km. The volcanic warning system was developed in the last years. Monitoring is mainly based on seismic surveillance, geochemical methods and field observations. Seismic stations are installed in the volcanoes San Cristóbal, Telica, Cerro Negro, Momotombo, Masaya, Mombacho, Concepción. Successful warnings several days prior volanic eruptions have been emitted in 1994 (Telica), 1995 (Cerro Negro), 1997 (San Cristóbal). Civil Defence and local authorities used these warnings to improve the communication to the respective regions, concentrate media and personnel and to inform the population about the existing evacuation plans. A monitoring system is in development for Masaya volcano to warn against extreme concentrations of volcanic gases.