geomagnética

Geomagnetism refers to the magnetic field of the Earth. This field is generated by the motion of molten iron and nickel in the outer core of the planet, a process known as the geodynamo. The geomagnetic field extends from the Earth's interior to where it meets the solar wind, a stream of charged particles emanating from the Sun. It is approximately dipolar, with the magnetic poles near, but not exactly at, the geographic poles.

The geomagnetic field is crucial for life on Earth. It protects the planet from solar and cosmic radiation, which can be harmful to living organisms. It also plays a role in navigation, as many animals, including birds and sea turtles, use it for orientation. Additionally, the field is used in various technological applications, such as compasses and magnetic surveys.

The geomagnetic field is not static; it changes over time. These changes are known as geomagnetic secular variation. The field also undergoes periodic reversals, where the magnetic poles switch places. The last such reversal occurred approximately 780,000 years ago.

The study of geomagnetism involves measuring the Earth's magnetic field and its variations. This is done using magnetometers, which can be ground-based, airborne, or satellite-based. The data collected is used to create geomagnetic models, which help in understanding the Earth's interior and its processes.