This phenomenon underwent a change 784,000 years ago named for Bernard Brunhes and Motonori Matuyama. Bauer (10[1])plots compare this phenomenon’s dip angle with its declination, which is zero on agonic (10[1])(“ay-gonic”) lines. (-5[1])Changes in this phenomenon’s orientation delineate chrons. (-5[1])This phenomenon’s strength reaches a minimum at the South Atlantic Anomaly, (10[2])where the van Allen (-5[1])belts are closest to the surface. Dynamo theory posits this phenomenon (10[1])is produced by the convection (-5[1])of iron and nickel. (10[2])The interaction (10[1])of (-5[1])solar wind with this (-5[1])phenomenon forms aurorae. (10[1])For 10 points, (10[2])the Earth’s core produces what phenomenon that makes compasses point north? (10[1])■END■ (10[3]0[1])