This action is for the maintenance of the Guerrero accelerograph array. The array consists of 30 strong motion accelerographs for recording earthquake-induced strong ground motions. The instruments are installed in Guerrero and neighboring states in Mexico. The array was installed under NSF award 82-19432, the installation and continued operation of this array being a cooperative project between the University of Nevada at Reno and the Institute of Engineers of the National University of Mexico. Earthquake hazard mitigation efforts are predicated upon an understanding of the strong ground motions that are induced by earthquakes. While small earthquakes are common in seismic zones, large damaging earthquakes are rare and, so far, unpredictable. As a result, information needed on strong ground motions is scarce, and there is an urgent need to obtain this data. The Guerrero array is strategically placed so as to record ground motions from three seismic gaps (areas where earthquakes are predicted to occur in the near future) for each of which large earthquakes are expected. It was still being installed when the September 19, 1985 earthquake hit Mexico City and excellent strong ground motion records were obtained; these records continue to yield valuable information on earthquake hazard mitigation.
