16 terms

Environmental Geology Lab

Topo Map
a 2-dimensional representation of the 3-dimensions surface of the Earth.
refers to the landscape of that area, or the change in elevation to the surface represented by hills and valleys.
Contour Lines
Lines that connect points of equal elevation.
Contour Interval
Elevation difference between 2 successive contour lines.
Index Contour
Every 5th contour line--drawn as bolder lines an are labeled with their elevation.
Commonly named after th major geographical feature within the map area.
most commonly displays north at the top of the page.
Geographic North
North pole is the northern end of the Earth's rotational axis
Magnetic North
direction toward which a magnetic needle of a compass points.
is the part of the map where the explanation of the symbols used on the map are found.
Fractional Scale
means the one unit of length on the map equals how ever many units of the Earth's Surface. Example: 1:24000
Graphic Scale
a line or bar that is divided to relate distances on the Earth's Surface to distances on the map.
parallels, lines drawn from E to W on the sufrace of the Earth. Measurd N and S from the 0 degree reference line, or Equator, which divides earth into northern and southern hemispheres--written with N or S after numerical measurement.
Merideans, are drawn from N to S on surface of theEarth. Measure E and W ofthe 0 degree reference line, or prime meridean--written with E or W after numerical measurement--E and W of Prime Meridean in Greenwich, England.
Grid pattern created by starting at baselines and surveying additional E and W lines.
starting at the principal merideans and surveying additional N and S lines.