isogone
Noun: A line on a map connecting points on the Earth's surface that have the same magnetic declination. Magnetic declination is the angle between magnetic north (the direction a compass needle points) and true north (geographic north).
The term "isogone" is a specialized term used primarily in cartography, geology, and navigation. It is used to describe a specific type of contour line on maps, particularly nautical or aeronautical charts.
Examples: * The navigator carefully studied the isogones on the chart to correct the compass course for the magnetic variation. * This map of the region includes isogones to aid in precise orientation. * The isogone marked "0°" is called the agonic line, where magnetic north and true north align.
- Plural Form: The standard plural form is isogones.
- Related Concept - Isogonic Chart: A map that primarily displays a series of isogones is often called an isogonic chart.
- Isogonic (adjective): Pertaining to or having equal magnetic declination.
- Example: The isogonic lines converge near the magnetic poles.
- Agonic Line (noun): A specific isogone where the magnetic declination is zero.
- Isoclinic Line (noun): A line connecting points with the same magnetic dip or inclination (a different magnetic element).
- Isogonic line: This is a full, descriptive synonym.
- Line of equal declination: A descriptive phrase with the same meaning.
"Iso-" is a prefix from Greek meaning "equal," and "-gone" is from the Greek "gonia," meaning "angle." Therefore, "isogone" literally means "equal angle." It is a technical term not commonly used in everyday conversation.
- an imaginary line connecting points on the Earth's surface where the magnetic declination is the same