FORCES THAT CHANGE THE
SURFACE OF THE EARTH
Mountain Range, Canyon, & Delta
Landforms are subject to change due
to agents of weathering
water
wind
ice
Grand Teton Mountain Range
Wyoming
Predict how weathering will change this
mountain range.
Which agents of weathering might work
on these mountains?
How would changes to this mountain
range be reflected on a map?
Grand Canyon
Arizona
Predict how weathering will change this
canyon.
Which agents of weathering might work
on this canyon?
How would changes to this canyon be
reflected on a map?
Mississippi River Delta
Louisiana
Predict how weathering will change this
delta.
Which agents of weathering might work
on this delta?
How would changes to this delta be
reflected on a map?
Thinking Topographically
• Topographic Maps-- 3-d ups and downs
of the terrain shown on a 2-d surface
• Topography – shapes and features of the
Earth’s surface
Terms to Know and Understand
• Contour lines – connect places on a
topographic map of the same elevation
• Elevation – height above sea level
• Contour line intervals – vertical distance
between contour lines
Topographic Labeling
• Topographic maps:
– must have scale and interval defined.
– use color
– use index contours ( wider lines with elevations)
Goal for today
• Go to my webpage and go through the following
links:
– Map Match
– Reading a Map
When you finish, pick up a pack of vocabulary cards,
match the term with the definition and write them on a
sheet of paper.
Topography
The study of the shapes and features of the
Earth’s surface.
Topographic Map
Shows the three dimensional shape and
elevations of an area of land in two
dimensions
Elevation
Height above sea level
Contour line
Line that connects places on a topographic
map that are all at the same elevation
(eventually a closed loop)
Contour line
Contour Line Interval
The vertical difference in elevation between
neighboring contour lines
contour line interval
Relief
The difference between the highest elevation
point and the lowest elevation point on a
map
200
300
400
Units = feet
What is the relief of this map?
What is the contour interval of this map?
Topographic Map Rules
Contour lines are closely spaced on steep
slopes.
Contour lines are widely spaced on gentle
slopes.
Topographic Map Rules
Where a contour line crosses a stream or valley,
the contour line bends to form a “V” that
points upstream. In the upstream direction, the
successive contours represent higher
elevations.
Topographic Map Rules
Contour lines near the top of a hill form
closed, circular shapes. The top of the hill is
higher than the highest closed contour line.
Topographic Map Rules
Depressions without outlets are shown by
closed hatched contours. The contour lines
have short lines on the inside that are
pointing down slope. The bottom of the
depression is lower than the lowest closed
contour line.
Satellite Map
A map made of pictures of the Earth taken
from a satellite orbiting the Earth.