magnetic meridian
Học thuậtThân thiện
Definition
- Noun:
- An imaginary line passing through both magnetic poles of the Earth: A
magnetic meridianis a conceptual line on the Earth's surface that connects the North and South Magnetic Poles. It indicates the local direction of the Earth's magnetic field.
Usage
- The term is used in geography, navigation, and geophysics to describe orientation relative to Earth's magnetic field, as opposed to geographic lines.
- It is a fixed conceptual line for a given location, unlike the moving needle of a compass, which aligns with it.
- Example: "To calibrate the compass, it must be aligned with the local ."
- Example: "The angle between the geographic meridian and the at this location is 15 degrees west."
Advanced Usage
- In Navigation: The is the reference line for determining a vessel's or aircraft's magnetic heading. The difference between true north (geographic meridian) and magnetic north () is called magnetic declination.
- Example: "Pilots must account for the variation between the true meridian and the magnetic meridian when plotting a course."
Variants and Related Words
- Magnetic Declination (Variation) (n): The angle on the horizontal plane between magnetic north (the ) and true north (geographic meridian).
- Magnetic Pole (n): Either of the two points on the Earth's surface where the lines converge and the magnetic field is vertical.
- Geographic Meridian (n): An imaginary line connecting the geographic North and South Poles.
Synonyms
- Magnetic north-south line: A descriptive synonym emphasizing its directional nature.
Related Concepts (Not Phrasal Verbs or Idioms)
- Agonic Line: The line on a map connecting points where the and geographic meridian coincide (i.e., where magnetic declination is zero).
- Isogonic Line: A line on a map connecting points of equal magnetic declination relative to the .
Noun
- an imaginary line passing through both magnetic poles of the Earth