Coast effect on geomagnetic variation fields in Southwestern Nigeria: a preliminary note

Summary Gough-Reitzel recording magnetometers were deployed at five sites in southwestern Nigeria to study the night time geomagnetic variation fields and determine the induction effect in the area. TheZ (vertical) component field shows strong positive correlation with theH (horizontal) component field perpendicular to the southwestern Nigeria coastline. The induction arrows point in the direction of the Atlantic ocean for periods of 25, 42 and 73 minutes but decrease gradually inland. All these indicate normal ?coast effect? as the main induction anomaly in this region. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.