Introduction

 

The Instituto Nicaragüense de Estudios Territoriales (INETER) presents this Annual Catalogue, "Sismos y Volcanes de Nicaragua, 2006" with the purpose to inform in a summarized form on the seismic, volcanic, and geologic phenomena in Nicaragua, the  development of the surveillance networks and on the progress of the projects of investigation and development. The content of this catalog is based on the monthly bulletins that the Department of Geophysics publishes regularly.

 

The Geophysical Department of INETER has the principal responsibility to monitoring and early warning the seismic, volcanic and geologic phenomena in Nicaragua, operates networks of seismic and geophysical stations and performs the volcanic surveillance. It also carries out scientific studies on the dangerous geologic processes in Nicaragua and develops a Geographical Information System (GIS) on these phenomena.

 

The most important geologic event in 2006, it was the eruption of the volcano San Cristóbal, that began the day 21 of April of the 2006 with increase of seismic tremor, two days later the eruption with small explosions began, arriving to their maximum April 24. The ashes fell until the city of Chinandega.

 

Other important events reported in this catalog are; February, April and August (Golfo de Fonseca), September (Isla de Ometepe) and December (El Astillero). In October, a collapse in the intercráter of the Santiago, Masaya volcano, appearing a lake of lava.

 

There is included information on other seismic events, earthquakes, seismicity in form of seismic swarms occurring on inhabited areas and events felt by the population mainly in the Pacific Region.

 

The seismic and volcanic surveillance of the Nicaraguan active volcanoes was guaranteed during all the year. 55 field visits ware made to the active craters, fumaroles and other sites.

 

During 2006, Geophysical Department revised reports submitted by private geologists and emitted 78 guarantees on their work. Geologic studies in Managua and other regions of Nicaragua. This are required for the local regulations in order to obtain the permission of construction.

 

Many projects produce geographic coverage of Geologic Hazard, vulnerability and risk were integrated in the GIS of Geo-Risks which is an important tool for the basic investigation and the information to the public about disaster prevention in Nicaragua.