Implication of Focal Depth, Temporal and Magnitude Distribution of Earthquakes in Oceanic Ridges
O. S. Hammed *
Ondo State University of Science and Technology, Okitipupa, Nigeria.
M. O. Awoyemi
Obafemi Awolowo University, Ile-Ife, Nigeria.
G. O. Badmus
Afe Babalola University, Ado-Ekiti, Nigeria.
A. K. Bello
Bells University of Technology, Ota, Nigeria.
A. F. Majors
Bells University of Technology, Ota, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This research aimed at investigating the focal depth, time and magnitude implication of earthquakes associated with the oceanic ridges. Oceanic ridges studied in this research were Mid Atlantic Ridge, Chile Ridge and Pacific ridge. The data were extracted from the earthquake catalogue of Northern California Earthquake Data Centre U.S.A. The data were obtained for the magnitude range of 1.0 - 8.0 for earthquakes that occurred along these oceanic ridges for the period of 1981 - 2010. The data were analyzed using magnitude, focal depth and frequency classification techniques. In the oceanic ridges studied, the shallow focus earthquakes were very predominant. The earthquakes recorded in the Mid-Atlantic Ridge outnumbered the Chile and Pacific Ridge earthquakes. This indicates that the phenomena that are associated with seismicity such as rate of tectonic divergence of oceanic plates, crustal and sub-crustal stress accumulation are enormous in the Mid-Atlantic Ridge. Thus the Atlantic Ocean is mostly prone to the tsunamigenic earthquake risks.
Keywords: Oceanic ridges, tsunamigenic, focal depth, frequency, magnitude