Elevation refers to the vertical distance of a point or object above a reference point, typically a standardized baseline such as sea level. It is a fundamental concept in geography, geology, cartography, and engineering, used to describe the height of landforms, structures, or natural features relative to a common datum.
Key Details:
- Reference Point: The most common reference is mean sea level (MSL), the average height of the ocean’s surface over time (accounting for tides and waves). This provides a consistent global baseline.
- In some regions, local datums (e.g., "Ordnance Datum" in the UK) may be used for practical purposes.
- Measurement: Elevation is measured vertically (not along slopes) using tools like:
- GPS (Global Positioning System): Calculates height via satellite signals.
- Leveling instruments: Traditional tools (e.g., transits, laser levels) for precise ground measurements.
- Topographic maps: Display elevation using contour lines (lines connecting points of equal height).
- Examples:
- Mount Everest has an elevation of approximately 8,848 meters above sea level.
- A city located in a valley might have an elevation of 200 meters.
- The Dead Sea, the lowest land point on Earth, has a negative elevation (about -430 meters, meaning it is 430 meters below sea level).
Related Terms:
- Altitude: Often used interchangeably with elevation but may refer specifically to height above the Earth’s surface (e.g., an airplane’s altitude).
- Relief: The difference in elevation between the highest and lowest points in an area (e.g., a mountain range has high relief).
Understanding elevation is crucial for activities like navigation, urban planning, agriculture (drainage), and climate studies (temperature decreases with elevation).