General Model for the Global Variation of Seismic Energy Released with Oceanic Lithosphere Age.

Nicolás Pinzón Sr, Universidad Nacional de Colombia, Bogota, Colombia and Carlos A Vargas-Jimenez, National University of Colombia, Bogotá, Colombia
We have assessed empirical relationships between the age of the oceanic lithosphere and the systematic decrease in seismic energy released from the axis of mid-ocean ridge systems towards its axial flanks. These observations are substantiated based on three cross-sections of the East Pacific Rise (EPR), four sections in the Mid Atlantic Ridge (MAR), and two sections in the Central Indian Ridge (CIR). Our analysis evaluates the main physical factors involved in the variations of magnitude and recurrence of seismic events with the oceanic lithosphere age between different spreading centers. The results suggest behaviors close to some empirical relationships used by previous authors to relate the variation of heat flow and seafloor bathymetry with the age. Based on the nine cross-sections used, we conclude that the results of this study are consistent along ocean floors no older than 13 Ma. This global model constitute an additional tool for understanding tectonic processes, including the effects in seismicity and lateral evolution for the thermal structure of the lithosphere beneath spreading centers.

Keywords: Seismic Energy, Mid-Ocean Ridges, Heat Flow, Oceanic Lithosphere Age.