Peligro, vulnerabilidad, riesgo y la posibilidad de desastres sísmicos en el Perú

Abstract

One basic condition for a sustainable development of a nation is a positive proac- tive management on disaster risk reduction. Such action requires previous knowl- edge and documentation about hazardous phenomena or events, their dangerousness assessment, and the vulnerability evaluation of: The people and their properties, the multiple societal aspects (economic, social, cultural, etc.), the infrastructure works, vital lines, and the environment. It also requires knowledge of the community copy- ing-capacities and its resilience. In this paper, the main concepts of risk manage- ment and the most important features of the seismicity in the Peruvian territory are reviewed. The following characteristics are pointed out for the collision-subduction of the Nazca-South American tectonic-plates seismicity environment: Earthquakes of large magnitude, very large mezoseismic areas, seismic accelerations that not exceed the Earth’s gravity on the continent, recurrence times tens to hundreds of years. The tectonic-readjustment-continental seismic environment is characterized by mezoseismic areas circumscribed to the activated geological faults – length: several tens of kilometers, width: few tens of kilometers – shallow hypocenters, geological faults with several meters of vertical displacement, the seismic ground acceleration exceeds the Earth’s gravity, the recurrence time of strong events is about one thousand years. The volcanic seismic environment is present in the tec- tonic block of southern Peru, and it is limited to the zone of presently active volca- noes. Their seismic activity is of low hazardousness. The probabilistic seismic hazard map of maximum accelerations, for 10% of probability of exceedence in 50 years, shows the largest values for the central and southern coastal area of the coun- try: 0.5-0.7 g; in the northern coastal areas this values are 0.4-0.5 g. In the “Sierra”