It is the magnetic field that extends from the interior of the Earth to the point where it meets the solar flux of charged particles emanating from the Sun. The magnetic field resembles the field of a large bar magnet near its center or that due to a uniformly magnetized sphere. Its origin is thought to be generated deep within the Earth's core. On the surface of the earth, the pole of this equivalent bar magnet, closest to the geographic north pole, is actually a “south” magnetic pole. This paradoxical situation exists because by convention the end of the needle of a north-seeking compass is defined as pointing north but must point to an opposite direction pole or South Pole of the Earth's magnetic field. The field flux lines show the pattern usually common to a small magnet, as shown in Figure 1. The direction of the field lines at the equator is horizontal while at the north and south magnetic poles it is vertical. This geometry is important in the interpretation of magnetic anomalies. The total strength of the Earth's field is not perfectly asymmetric with respect to the geographic North Pole, for example the magnetic north pole in northern Canada is more than 1,000 miles from the geographic pole. The Earth cannot be represented exactly by a single bar magnet but has numerous higher-order poles and very large-scale anomalous features due to unknown characteristics of the generating mechanism in the Earth's core. As shown in Figure 1, the solar wind, or the constant flow of particles and electric currents from the sun, distorts the field lines. Asymmetric field deviation is the anomalous set of features of the Earth's crust caused by local variations in magnetic minerals and other features that distort the local Earth's magnetic field. The magnetic field of... middle of paper... ...may have been reoriented and as the Earth's field is known to have changed its orientation over geological and even historical time. Often rocks are reverse magnetized, so measurements of this remanent magnetization are a useful aid in the interpretation of rocks producing an observed anomaly and indeed accessible. In paleomagnetism and archaeomagnetism, the field depends in particular on the precise determination of the orientation of the frozen paleo-fields as measured in a given rock or other sample. Works Cited APPLICATIONS MANUAL FOR PORTABLE MAGNETOMETERS By S.BREINERGeometrics, 395 Java DriveSunnyvale, California 94086U.SASOLID STATE PHYSICSBy SOPILAI.Adapted from ES304 – Geophysical Prospecting, Department of Earth SciencesUniversity of Melbourne, Australia.By Dr.Kamar Shah Ariffin.