Longitude

Definition

Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. Measured in degrees, it helps to determine how far a location is from the Prime Meridian, which is defined as 0° longitude. This measurement is crucial for navigation and mapping, influencing how people understand their position on Earth in relation to celestial bodies and local geography.

5 Must Know Facts For Your Next Test

1. Longitude lines run vertically from the North Pole to the South Pole and are used in conjunction with latitude lines to pinpoint exact locations on Earth.
2. The concept of longitude was crucial for the development of accurate maritime navigation, allowing sailors to determine their east-west position at sea.
3. Inaccurate measurements of longitude historically led to navigational errors and shipwrecks until the invention of the marine chronometer in the 18th century.
4. Each degree of longitude varies in distance depending on its position; at the equator, one degree is about 69 miles, but this distance decreases as one moves toward the poles.
5. The International Date Line, located at approximately 180° longitude, serves as the demarcation for calendar days, impacting global timekeeping.

Review Questions

• How does longitude differ from latitude in defining geographic locations?
  • Longitude measures the east-west position of a location on Earth, while latitude measures the north-south position. Together, they form a grid system that allows us to pinpoint any location accurately. Latitude lines are parallel to the equator and remain equidistant, while longitude lines converge at the poles and vary in distance apart based on latitude.
• Discuss the historical significance of longitude in maritime navigation and its impact on global trade.
  • Longitude was vital for maritime navigation, especially before reliable methods were developed. Accurate knowledge of longitude allowed sailors to determine their precise location at sea, minimizing navigational errors that could lead to shipwrecks. This capability significantly enhanced global trade routes and exploration during the Age of Discovery, facilitating connections between continents and cultures.
• Evaluate the technological advancements that improved our understanding and measurement of longitude over time.
  • The determination of longitude improved dramatically with technological advancements such as the marine chronometer invented by John Harrison in the 18th century. This device allowed sailors to keep accurate time at sea, which was essential for calculating longitude based on celestial observations. The development of precise maps and navigational instruments further enhanced our ability to measure longitude accurately, leading to safer voyages and more efficient exploration of the globe. These advancements not only transformed navigation but also reshaped economic interactions and cultural exchanges between different regions.

Related terms

Latitude:

Latitude is a geographic coordinate that specifies the north-south position of a point on the Earth's surface, measured in degrees from the equator.

Prime Meridian: The Prime Meridian is the meridian (0° longitude) from which all other longitudes are measured, passing through Greenwich, England.

Celestial Navigation: Celestial navigation is a technique used by sailors to determine their position on Earth by observing celestial bodies like stars and planets.