Note Outline: Geophysical Surveying Using Magnetics Methods

A collection of these notes in .pdf format is available for downloading here.

Introduction

• Historical Overview
• Similarities Between Gravity and Magnetics
• Differences Between Gravity and Magnetics
• Magnetic Monopoles
• Forces Associated with Magnetic Monopoles
• Magnetic Dipoles
• Field Lines for a Magnetic Dipole
• Units Associated with Magnetic Poles

Magnetization of Materials

• Induced Magnetization
• Magnetic Susceptibility
• Mechanisms of Magnetic Induction
• Susceptibilities of Common Rocks and Minerals
• Remanent Magnetism

The Earth's Magnetic Field

• Magnetic Field Nomenclature
• The Earth's Main Field
• Magnetics and Geology - A Simple Example
• Temporal Variations of the Earth's Main Field - Overview
• Secular Variations
• Diurnal Variations
• Magnetic Storms

Magnetometers

• Instrumentation Overview
• Fluxgate Magnetometers
• Proton Precession Magnetometers
• Total Field Measurements

Field Procedures

• Modes of Acquiring Magnetic Observations
• Assuring High-Quality Observations - Magnetic Cleanliness
• Strategies for Dealing with Temporal Variations
• Spatially Varying Corrections?
• Correcting for the Main-Field Contributions

Magnetic Anomalies Over Simple Shapes

• Comparison Between Gravity and Magnetic Anomalies
• Magnetic Anomaly: Magnetized Sphere at the North Pole
• Magnetic Anomaly: Magnetized Sphere at the Equator
• Magnetic Anomaly: Magnetized Sphere in the Northern Hemisphere