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Name ____________________________________________
GOL 105: Physical Geology – Unit 10 lab, part II
Topographic Profile
Objective:
The objective of this assignment is to familiarize you with the process of creating a topographic profile
from the data presented on a topographic map.
Directions:
I have provided you with a section of the Topographic Map (Figure 2) from near Newport, PA, just north
of Harrisburg, PA. The link for this map is provided below:
https://ngmdb.usgs.gov/topoview/viewer/#14/40.5232/-77.0390 (You donâ€™t â€œneedâ€ this link as we
reproduce the relevant map as Figure 2.)
The cross-section that you will use has been drawn and labelled on Figure 2 with starting (A) and ending
(B) points. You can draw this cross-section on the provided graph (Figure 3).
1) Using a scap piece of paper, line up the edge of the paper along the cross-section line AB and
transfer the locations and labels (elevations) of the beginning of the line (A), the end of the line
(B), and any location where a bold topographic line intersects the cross-section line. You can do
ALL of the topographic lines, but you will likely only need to use the bold lines to produce an
relatively accurate profile. The contour interval on this map is 10 meters, and as is typical of
most topographic maps, every 5th topographic line is bold. Thus the bold lines represent 50 meter
intervals on the map (10 meters x 5 = 50 meters). This step is illustrated in Figure 1a. Only a
portion of the lines have been included on this illustartion. You will need to label the locations of
ALL points where a bold topographic line intersects your cross-section line.
2) Now you are going to transfer this data on to the graph provided in Figure 3. First, you will need
to determine the range (lowest and highest) of elevations in your data from the topographic map
and choose a scale for the vertical axis on the graph is Figure 3. Make sure your scale includes
all the elevations from your data and the labeling on the vertical axis is in equal and consistent
intervals. (see labeling of vertical axis in Figure 1b).
3) Lay your scrap paper with the data from the topographic map along the bottom horizontal axis of
the graph and draw a vertical line on Figure 3 at each point for which you have a contour
elevation data point (see Figure 1b).
4) Plot the data points on the graph and connect them with a single line representing the profile of
the land surface along your cross-section line A-B.
250 m
A
300 m
350 m
350 m
300 m
Elevation (meters)
a)
A
B
b)
400 m
350 m
300 m
250 m
B
Figure 1
A
Figure 2
B
Elevation (meters)
Topographic Cross-section/Profile
A
B
Distance (meters)
Figure 3