Geological study of natural risks in Nicaragua
The project in Nicaragua began in 1997. The first study was localized in the capital, Managua, where “all the eggs are in one basket“, as the local people say. The capital of Nicaragua was totally destroyed during the 1972 earthquake. A detailed study of volcanic stratigraphy and the location of the main faults is important for all construction activities in the city. The priority of Managua was later confi rmed by a project for studying faults, organized and fi nanced by international institutions and the World Bank, and in which several Czech geologists participated.
Studies in 1998 involved volcanological and geological fi eld work in the seismically and volcanically active area of Granada–Apoyo, where newly recorded faults were activated one year later during the catastrophic earthquake. Hurricane Mitch hit Nicaragua at the end of October, 1998. The western part of the country suffered considerable damages. The most damaged areas of the Casita Volcano and its surroundings were the subject of the Czech group’s 1999 study. The results of this detailed evaluation of the vulnerable neighbouring areas were immediatelly submitted to the local authorities for deciding on the further reconstruction of damaged areas.
Studies of natural risks in the Pacific region were completed in 2001. This entire region is endangered by the activity of recent volcanoes such as Cerro Negro, Telica, El Hoyo, Momotombo, Apoyeque and Cosigüina. The seismic instability of the area increases the danger, especially in areas along some young faults. Cities such as Chinandega and León are continuously exposed to volcanic danger, consisting of ash-fall, lava fl ows, and gas emanations. The Cerro Negro eruption in 2000 generated associated faults near the volcano, while seismic unrest in 2001 occurred in the vicinity of the Momotombo volcanic slopes where at geothermal power plant is situated.
A detailed study of the eruptive history of the famous Cosigüina volcano enabled the understanding of the processes that could induce such catastrophic events as occurred in 1835. During subsequent years the activity of the Czech geologists has been concentrated in the hilly region of central and northern Nicaragua, namely the provinces of Matagalpa, Jinotega, and Somoto. Similar to many parts of the country, these mountainous areas have been affected by natural disasters related to geological structure, rock composition, weathering, and deforestation. The demarcation of vulnerable areas together with suggestions on how for designing houses, linear constructions and agricultural facilities for avoiding future damage are the major objectives of the Czech Geological Survey’s team.
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