Elevation refers to the height above or below a fixed geographic reference point, known as a geoid. When elevation is above the geoid, it is known as altitude, and depth when it is below. In most cases, the geoid used is the Earth’s sea level, but in some cases the ground level is used as the reference point.
Elevation and Sea Level
The sea level, just like the Earth's surface, is not even and some places tend to be higher than others. The sea level that is used as the geoid refers to the mean sea level. The height of physical features such as mountains is measured from the sea level rather than the ground level. For example, when Mount Everest is said to be 17,057 ft tall, this height is measured from sea level rather than the vertical height. If the height of the mountain is measured from the seafloor, then Hawaii’s Mauna Kea would be the tallest at 32,696 ft. The lowest elevation on the surface of the planet is the shore of the Dead Sea, located on the border between Jordan and Israel, at an elevation of 1,385 ft below the sea level.
The Importance of Elevation
Elevation plays a crucial part in everyday life. Airplanes fly at a specified altitude to prevent mid-air collisions. It is also used in architecture and engineering to determine the center of gravity and the type of materials to be used. The elevation of a particular place can also help predict and prevent disasters such as flooding. Humans adapt to their environment, as some are adapted to higher elevations while others are adapted to low elevations. A sudden change in altitudes results in altitude sickness that leave patients experiencing difficulty in breathing. A majority of the world's population lives in coastal regions with elevations of 500 feet or less. The people of Tibet in Central Asia are adapted to living at 17,500 ft where crops cannot grow and the oxygen is extremely thin.
How Is Elevation Measured?
Elevation is measured using standard imperial or metric units of measure, as well as angles. Although it may seem to be an easy task, measuring the height of physical features such as mountains and the depth of valleys can be challenging and involves the use of modern technology and mathematical calculations. The height of a mountain is measured by placing GPS equipment on the peak and then using satellite to determine the elevation from the ground and the sea level. Measuring depth is even more challenging because it involves the use of sonar and radar technology.