All books

Professional

Apps About Coach Log in Start reading

Earth and Space Sciences · Glossary

What is Secular variation?

Definition 4.5 University Earth and Space Sciences — Year 3 · Chapter 4 — Geomagnetism and Palaeomagnetism

The secular variation is the slow change of the main field with time, over years to centuries, measured by the rate of change of its Gauss coefficients or of its elements at a place.

The dipole part of the main field, 1900–2025, every five years, from the IGRF: its moment (left) and the latitude of the north geomagnetic pole (right).
The dipole part of the main field, 1900–2025, every five years, from the IGRF: its moment (left) and the latitude of the north geomagnetic pole (right).
Read in context →