Integrated Aeromagnetic and Seismological Analysis of Intraplate Earth Tremors (2016-2018) in North –Central Nigeria
Alkali, A. *
Department of Geophysics Federal University of Technology, Minna, Niger State, Nigeria.
Alhassan, U.D.
Department of Geophysics Federal University of Technology, Minna, Niger State, Nigeria.
Akpan, O.U.
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria.
Lawrence Jane O.
Department of Geophysics Federal University of Technology, Minna, Niger State, Nigeria.
Udensi, E. E
Department of Geophysics Federal University of Technology, Minna, Niger State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The primary aim of this study is to use High-resolution aeromagnetic and seismological data from parts of North Central Nigeria to pinpoint the causes of the earth tremors that occurred in 2016 and 2018 in the region. Techniques such as upward continuation, First Vertical Derivative (FVD), and Center for Exploration Targeting (CET) grid analyses were employed to interpret the aeromagnetic data, while the earthquake parameters derived from the seismological data were analyzed to investigate the earthquake magnitude and location of earthquake epicentre using SEISAN. Upward continuation at 5 km depth revealed the presence of deep-seated faults. Similarly, a prominent discontinuity was identified using the First Vertical Derivative (FVD) method which traverses the study area, is suspected to represent the same paleostructure (Romanche). The Center for Exploration Targeting (CET) analysis identified four major structural trends: NE-SW, NW-SE, E-W, and NNE-SSW. The epicentres of the earth tremors at Jema’a (2016) and Municipal area council (2018) were observed to coincide with the emerging fault lines labelled (F4 and F8) in the study area. The findings indicate that the paleostructures coincide with the earthquake epicentres, suggesting a tectonic origin.
Keywords: Epicentre, magnitude, vertical derivative, upward continuation, tectonic origin