Kokonaismagneettikenttä

Kokonaismagneettikenttä refers to the total magnetic field present at a particular location. In geophysics, it is a fundamental concept used to study the Earth's magnetic field and its variations. The Earth's magnetic field is a vector quantity, meaning it has both magnitude and direction. Therefore, the total magnetic field is the resultant of all magnetic forces acting at a point, including contributions from the Earth's core, crust, and external sources like the Sun.

Geophysicists measure the total magnetic field using magnetometers. These measurements can reveal anomalies in the magnetic field, which are deviations from the expected regional field. These anomalies are often caused by variations in the magnetic properties of the rocks in the Earth's crust. For instance, rocks with higher concentrations of magnetic minerals like magnetite will create stronger local magnetic fields.

The study of the total magnetic field and its anomalies, known as magnetic surveying, is a widely used geophysical exploration technique. It helps in identifying geological structures such as faults, folds, and igneous intrusions, as well as locating mineral deposits that have distinct magnetic signatures. Magnetic data is also crucial for understanding the Earth's history, including paleomagnetism, which studies past magnetic field directions recorded in rocks. Changes in the total magnetic field over time, such as secular variation, are also monitored to understand the dynamics of the Earth's core.