magnetic equator
Học thuậtThân thiện
Definition
Noun: * Magnetic Equator: An imaginary line encircling the Earth, roughly parallel to the geographic equator, where the Earth's magnetic field is entirely horizontal. At this line, a freely suspended magnetic needle (like in a compass) will show no inclination or "dip"; it remains perfectly level.
Usage
The term is used in the fields of geophysics, navigation, and earth science to describe a specific geophysical coordinate. * Scientists measured the magnetic field's angle to accurately map the position of the magnetic equator. * The magnetic equator is also known as the aclinic line.
Advanced Usage
- The magnetic equator is not fixed and shifts gradually over time due to changes in the Earth's molten outer core.
- It does not perfectly align with the geographic equator; it is an irregular line that deviates north and south.
Variants and Related Words
- Aclinic Line: A direct synonym for the magnetic equator, from the Greek meaning "not leaning."
- Dip Equator: Another synonym, referencing the zero angle of magnetic dip.
- Magnetic Dip / Inclination: The vertical angle a magnetic needle makes with the horizontal plane, which is zero at the magnetic equator.
- Geomagnetic Equator: A related but distinct concept; it is the great circle equidistant from the calculated geomagnetic poles of an idealized dipole model of Earth's field.
Synonyms
- Aclinic Line
- Dip Equator
Notes
- The magnetic equator should not be confused with the geomagnetic equator. The magnetic equator is based on actual measurements of the Earth's complex magnetic field, while the geomagnetic equator is based on a simplified theoretical model.
Noun
- an imaginary line paralleling the equator where a magnetic needle has no dip