Mapping the Earth Flashcards
Define elevation
Distance from sea level
Define longitude
Distance in degrees east or west of the prime meridian
Define latitude
Distance in degrees north or south of the equator
Define equator
Imaginary line that separates Earth into northern and southern hemispheres
Define prime meridian
Reference point for longitude that passes through Greenwich, England, and represents 0°
Define Southern hemisphere
South side of the Earth divided by the equator
Define Northern hemisphere
North side of the Earth divided by the equator
Define Western hemisphere
West side of the Earth divided by the Prime meridian
Define Eastern hemisphere
East side of the Earth divided by the Prime meridian
Define North Pole
Found 90°N from the equator
Define South Pole
Found 90°S from the equator
Define Tropic of Cancer
Found 23 1/2°S from the equator
Define Tropic of Capricorn
Found 23 1/2°S from the equator
Define Arctic Circle
Found 66 1/2°N from the equator
Define Antarctic Circle
Found 66 1/2°S from the equator
Define topography
A detailed description or representation of physical features of an area shown on a map
Define contour interval
The distance between two contour lines
Define contour lines
Lines showing equal points in elevation
Define International Date Line
Line used to separate time zones. Found 180° from the Prime Meridian. Crossing from West to East, add a day. Crossing East to West, subtract a day
Define index contour
5th contour line. Bolded and usually labeled to show elevation
Define map scale
The scale between the representation on the map and the actual physical details
What does brown represent on a topographic map?
Contour lines, physical properties of the land
What does blue represent on a topographic map?
Bodies of water, rivers, oceans, lakes, streams, ponds, canals, etc.
What does green represent on a topographic map?
Forests, woodlands, etc.
What does black represent on a topographic map?
Roads, railroads, buildings, land boundaries, etc.
What does red represent on a topographic map?
Major roads, land boundaries, coordinantes, etc.
What does peach (and sometimes purple) represent on a topographic map?
Revisions
How do you calculate relief?
Subtract the lowest elevation from the highest elevation
What are the types of scales on a topographic map?
Fractional scale, graphical scale, and verbal scale
On a set of coordinates such as (3598, -8926), what digits show latitude? Which show longitude?
3598 would be latitude and -8926 would be longitude
What shows depressions in topographic maps?
Hachure marks
What shows valleys in topographic maps?
Straight (or almost) straight lines
What is the purpose of topographic maps?
To show the features of Earth accurately on a two-dimensional model
What is magnetic north?
The direction of north as defined by Earth’s gravitational field
What is true north?
The direction of north as defined by the geographic direction of north
What do topographic maps have to show?
Steepness of a slope, depths of a body of water, and the shape and elevations of hills, mountains, valleys, etc.
What are the rules of contour lines?
Rule 1 - every point of a contour line has the same elevation.
Rule 2 - contour lines separate uphill from downhill.
Rule 3 - contour lines do not touch or cross each other except at a cliff.
Rule 4 - every 5th contour line is darker in color. This is an index contour line.
Rule 5 - Contour lines are closer together in steep terrain and farther apart in flat areas.
Rule 6 - Contour lines close to form circles (or go off the map) and the inside of the circle is
the top of a hill.
Rule 7 - Closed depressions have hachure marks on the downhilll side of a contour line.
Rule 8 - Contour lines create V-patterns when they cross a valley (or drainage). The tip of the V
always points uphill.
Rule 9 - Contour lines create V (or U) patterns when they cross a ridge. The tip or blunt end of
the V or U at a ridge always points downhill.
Rule 10 - Contour lines on opposite sides of a valley or ridge occur in pairs.
