A permanent marker, usually metal, at a specific location on Earth's surface, that indicates an exact elevation or altitude

• Bench Mark

• Contour line

• elevation

• model

The difference in elevation indicated by 2 consecutive contour lines on contour or topographic maps.

• contour interval

• coordinate system

• polaris

• profile

an isoline on a topographic, or contour map that connects points of equal elevation on the surface

• contour line

• bench mark

• isoline

• longitude

A grid or a system of lines for determining location of a point on a surface, such as the latitude and longitude of a point on Earth.

• coordinate system

• bench mark

• field

• latitude

The vertical distance or height above or below sea level.

• elevation

• contour line

• profile

• parallels of latitude

The parallel of Earth midway between the geographic North and South poles with a latitude of 0 degrees.

• equator

• gradient

• isoline

• north pole

Any part of the Universe that has some measurable value of a given quantity at every point.

• field

• isoline

• equator

• model

The north and south poles of Earth with a latitude of 90 degrees; located at opposite ends of Earth's axis of rotation.

• geographic poles

• gradient

• contour line

• bench mark

The rate of change from place to place within a field; also called slope.

• gradient

• isoline

• coordinate system

• elevation

A line used on a model of a field, such as a map, which connects points of equal value of a field quantity.

• isoline

• equator

• bench mark

• elevation