Project Nariõ I: Crustal structure under southern Colombian-northern Ecuador Andes from seismic refraction data

Abstract

abstract A portion of the Colombian and Ecuadorian Andes associated with lowest values of the regional Bouguer gravity anomaly has been examined as a part of a 1973 multinational seismic refraction experiment, Project Narino, extending from 5°N to 2°S latitude using a Colombian lake shot point at about latitude 1°N, longitude 77°W. The data from these reconnaissance measurements seem best satisfied by synthetic seismogram record sections computed from models containing low compressional-wave velocity zones. The basic structures in the crust and upper mantle under Colombia and Ecuador are similar. Models from the Peru-Bolivia altiplano, a similar low-gravity region, correlate with those under Colombia and Ecuador.