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Seismicity, fault plane solutions, depth of faulting, and active tectonics of the Andes of Peru, Ecuador, and southern ColombiaThe long-period P waveforms observed for 17 earthquakes in the Peruvian Andes during 1963-1976 are compared with synthetic waveforms to obtain fault-plane solutions and focal depths. The morphological units of the Peruvian Andes are characterized: coastal plains, Cordillera Occidental, altiplano and central high plateau, Cordillera Oriental, and sub-Andes. The data base and analysis methodology are discussed, and the results are presented in tables, diagrams, graphs, maps, and photographs illustrating typical formations. Most of the earthquakes are shown to occur in the transition zone from the sub-Andes to the Cordillera Oriental under formations of about 1 km elevation at focal depths of 10-38 km. It is suggested that the sub-Andean earthquakes reflect hinterland deformation of a detached fold and thrust belt, perhaps like that which occurred in parts of the Canadian Rockies. From the total crustal shortening evident in Andean morphology and the shortening rate of the recent earthquakes it is estimated that the topography and crustal root of the Andes have been formed during the last 90-135 Myr.
Document ID
19840035870
Document Type
Reprint (Version printed in journal)
Authors
Suarez, G. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Molnar, P. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Burchfiel, B. C. (MIT Cambridge, MA, United States)
Date Acquired
August 12, 2013
Publication Date
December 10, 1983
Publication Information
Publication: Journal of Geophysical Research
Volume: 88
ISSN: 0148-0227
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAG5-19
Distribution Limits
Public
Copyright
Other