Need for the Determination of the Nigerian Fault Lines

Abstract

Earthquakes and Tremors are Tectonic activities traced to Crustal Motions with roots in the Continental Drift Theory. These activities occur mostly at Plate Boundaries and along or close to Fault Lines. Nigeria was erroneously considered aseismic in the past, but studies have shown that Nigeria was never aseismic as information on different Tremors and Earthquakes abound. The recent occurrences of Tremors in Abuja, the Nation’s Capital, call for a serious attention towards the definition of the Nigerian Fault Lines. An attempt towards the determination of the Fault Lines is made, using the Non-Geodetic and Geodetic Methods. The Non-Geodetic Method Seeks to connect the Epicenters of different Earthquakes and Tremors on record, in order to present a possible set of Fault Lines. Three Fault Lines, The Western Nigeria Fault Line, the Mid Nigeria Fault Line and the Eastern Nigeria Fault Lines were proposed. The Geodetic Method adopted the use of archived GNSS data from the Nigerian CORS stations between 2012 and 2014. Fourteen sites, ABUZ, BKFP, GCCT, CLBR, FPNO, FUTA, FUTY, GEMB, HUKP, MDGR, OSGF, RUST, ULAG and UNEC, were used for this experiment, and ten IGS stations, DEAR, ABPO, RAMO, DARK, MELI, ASCG, MOIU, ZAMB, NOT1, BHR4, were used for Network Stabilization in the experiment conducted with the GAMIT/GLOBK Software. The Mean Horizontal Velocity of Nigeria for the period was 22.5625±0.32583mm/yr East, 18.93±0.23417mm/yr North, found to agree with Bawa, Ojigi and Dodo (2018) and Altamimi et al (2011). The Analysis of the Position Solution, showed that stations along a particular line, share similar direction of motion, which agrees with the Non-Geodetic Proposal. It was recommended that in order to adequately and accurately determine the Fault System in Nigeria, about three times the existing number of CORS Stations must be established, and their data made readily available to researchers.

Keywords: Earthquakes, Tremors, Fault Lines, GAMIT/GLOBK

DOI: 10.7176/JEES/11-10-05

Publication date:October 31^st 2021