Geophysics II

Abstract

Treatment of fundamental aspects of gravimetry and geomagnetism. We review the fundamentals of gravity set out by Newton, orbital dynamics and gravity applications in exploration geophysics. We will explore the mechanisms by which the geomagnetic field is created, how geomagnetic measurements can be used for resource exploration, and how palaeomagnetism tells us about the history of the Earth.

Objective

Treatment of fundamental aspects of geophysics in the area of gravimetry and geomagnetism: methods and applications. Our objectives are to learn fundamental theories and techniques relevant to the geomagnetic and gravity fields, but also to put them into practice in a quantitative way. We will learn to use mathematical techniques make quantitative estimates of geophysical phenomena. The examination will require the implementation of mathematics to solve questions in the spheres of geomagnetism and gravity.

Content

Gravimetry: gravitation, Earth rotation, centrifugal force. Gravity, geoid, reference ellipsoid, normal gravity. Reduction of gravity measurements, gravity anomalies. Isostasy: models of Pratt, Airy, Vening Meinesz. Interpretation of gravity anomalies and relationship to dynamic and static features. Geomagnetism: geomagnetic fields of external and internal origin, dipole and non-dipole fields, diurnal variation, magnetic prospecting, magnetic anomalies. Rock magnetism, remanent magnetizations. Paleomagnetism: sample treatment, secular variation, geocentric axial dipole field, apparent polar wander curves, polarity reversals, magnetic stratigraphy.

Resources