Before of the Managua earthquake in 1972, with the objective of obtain exact information about the seismic threat in Nicaragua was prepared a project with the geological survey of United States. In 1975, two year later, was distributed with assistance of this institution, the first seismic network which it was constituted by 16 seismic stations in the Pacific region of Nicaragua. This network in that epoch used advanced technology. In the new seismic surveys, in this institute was registered continually the oscillation ground in special picture. The register was process daily,The first report it prepared in October of 1975 with the information of the data of 3 month (April-June). Clearly was identified the areas of major activity in the Pacific Ocean and the volcanic chain. This was the first time in the history that was localized exactly the quake that occurred in Momotombo volcano. By other side, not much quakes occurred in or near of Managua, point that was very much discussed. After some years was detected, that in an area of the Pacific Ocean occurred a small quantity of quake while in the neighbors areas occurred more. In 1980 year, seismologists and Nicaraguan technician, will published in the nature magazine an article about this phenomena (called "gap") with the supposition that the unpresence of quakes will prepared a earthquake in Nicaraguan Pacific. An earthquake was occurred 12 year later in this zone and originates a tsunami the first day of September of 1992. From that way the network seismic let prognostic an earthquake, the first time in the history of Nicaragua. In 1980 the seismic networks disappeared, due the exodus of scientifics in the country. In 1990 with the politics changes was possible the reinstallation of a new seismic network, The seismic network has until 2001, 57 stations from which 36 is telemetric stations, 19 acelographics seismic stations, a wide station and a digital station autonomic . The telemetric stations,which are located in remote sites,send transmission continually to the seismic central in Managua those telemetric stations are quiet useful for volcanic surveillance. With this stations Nicaragua was integrated in a worldwide network of seismic stations with high precision. The new network of Nicaragua is now the biggest in Central America. Its data are useful not only for Nicaragua,also is useful to all Central America, because its data are integrate in a common process of others seismic station of Central America.

Fig. 5 National seismic network.(INETER)