Altitude

Maximum height and depth on Earth

The altitude is the vertical distance between any point on Earth in relation to sea level. To calculate the altitude, the sea level is taken as a reference, and for this reason the altitude is expressed with a figure in meters followed by the abbreviation s. no. m., that is, m s. no. m. ('meters above sea level').

In geography, altitude is the vertical distance of a point on Earth from sea level, called elevation above mean sea level, in contrast to height, which indicates the vertical distance between two points on the earth's surface; and flight level, which is the altitude based on standard pressure using an altimeter, which is more than 20,000 feet above mean sea level.

In continental Europe, almost all of Latin America, and in other parts of the world, altitude is measured in meters. In the United States it is generally measured in feet, but this country has agreed to gradually replace that measurement system by the International System of Units (SI).^{[citation required]} In aviation, feet are generally used throughout the world except in the countries of the former Eastern Bloc, since the planes of the former Soviet Union carry altitude indicators in meters.

In meteorology, altitude is a factor of temperature changes, since it decreases, on average, 0.65 °C for every hundred meters of altitude in the mid-latitudes (in the temperate and subtropical zones of the world).

In Spain, altitude is normally measured from sea level in Alicante, Valencian Community.