Identification of Causative Factors of Seismotectonic Activities in Kwoi and Mpape Using Aeromagnetic Data

An aeromagnetic reconnaissance study is adopted to delineate the subsurface structures of the seismotectonic activities on 11th-12th September, 2016 at Kwoi, Kaduna State, northwestern Nigeria and on the 5th–7th September, 2018 at  Mpape, Federal Capital Territory, Abuja, northcentral Nigeria. The map was processed using Geosoft Oasis Montaj software version 6.4.2.  Data enhancement techniques were carried out and interpreted to ascertain the causative factors of recent earthquakes in Nigeria. Analysis on the TMI map shows both positive and negative anomalies ranging from -48 nT to 88 nT. The high magnetic susceptibilities are prominent around the central, southern, southwestern and northeastern parts of the study area, which correspond to Kwoi and Mpape.  The intensity of the RTE map ranges from -29 nT to 73 nT, with high-intensity magnetic response trending NE–SW direction, and low-intensity striking NW–SE direction. The FVD map is characterized by anomaly gradient values ranging from -0.5 nT/km to 0.03 nT/km. Linearments shown by the FVD, TDR, and Upward Continuation maps are continuous, discontinuous and deep seated. The long linear features represent major fault lines on the map cutting across Kwoi and Mpape, trending NE–SW and SE–NW direction, which coincides with the regional North Atlantic Romanche fault system. The study’s findings have provided significant insights into the subsurface structural architecture of seismotectonic activities within Kwoi and Mpape northwestern and northcentral Nigeria.