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Lab 4: Map Fundamentals
and Interpretation
What are maps?
● Maps are 2-dimensional
depictions of the Earth’s
surface.
● Portray surface
structures and the
distributions of
geographic phenomena.
● All maps need: a title, a
scale, a legend, and a
north arrow.
● May have a grid with coordinates — a locational
system
● Cartographers are people who draw or produce maps
GLOBES
● Advantages
● Preserve area
● Accurate replication of
distances
● Disadvantages
● Bulky, difficult to use
for analysis
● Must be huge to get
any sort of detailed
information about a
place
● Ratio/Scale issues
(1:1 vs. 1:41,000,000)
There are two kinds of maps:
Reference/Physical
● A map designed to
show where
geographic features
are in relation to each
other.
● Tend to show
physical,
environmental, and
human-built
environments
Thematic
● A map designed to
show a particular
geographic
phenomenon or
theme.
● Tend to show human
geography,
demography, social,
political, and
economic variation
over space
Examples
Map Scales
Maps have scales which tell the map reader the
difference between map distances and actual
(terrestrial) distances: scale should be thought of as
the ratio between map and Earth.
Scale = Distance on Map
________________
Distance on Ground
For example: 1 inch on the map = 1 mile in person
Map Scales
There are three types of map scales.
Verbal: Where one inch to thirteen miles means 1 inch
on map = 13 miles on the ground.
Ratio (Representative Fraction): Where 1 : 823,680
means 1 inch on map = 823,680 inches on the ground.
Or 1 of anything = 823,680 of those on the ground.
Linear: Using a scale bar to judge distance. Not as
accurate.
Map Projections (all maps have one)
❏ Projections are how we
transform our 3D Earth
to a 2D map.
❏ There are many
different types of
projections and all
have some degree of
distortion.
❏ There is no perfectly
accurate projection.
Mercator Projection
● Direction is preserved
● True shapes and
distances within 15
degrees from the
equator
● Distortion at the poles
and northern
hemisphere
● Example of cylinder placed over globe
Albers Equal Area and Robinson
Projections
● Areas are proportional to the
● Better balance of size
same areas on the Earth
● Directions are reasonably
accurate in limited regions
● Distances are true on both
standard parallels
● Example of cone placed over
globe
and shape
● Distortion reduced
● Greatest at poles
● Distances are still not
perfect
Gall-Peters projection
Latitude
Lines of latitude circle the
globe from East to West,
and measure the angular
distance, North or South,
between the Equator and
a given place, from the
“center” of the Earth.
Longitude
Longitude (meridians)
runs North to South, and
measures the angular
distance, East or West,
between a given location
and the Prime Meridian
(Royal Observatory in
Greenwich, England)
from the axis of the
earth.
Isolines
● Connect points of equal value
● Types:
● Contour Lines
● Connect points of equal elevation
● Isotherm Lines
● Connect points of equal
temperature
● Isohyet Lines
● Connect points of equal
precipitation
● Isobars Lines
● Connect points of equal pressure
Tips for Reading a Topographic Map
● The closer the contour
are to each other, the
steeper the slope
● Hachured lines indicate
a depression or a
decrease in elevation
● Pay attention to the
legend and the scale
● Pay attention to units
What is the contour interval for
this map?
What is the contour interval for
this map?
25 meters
What is the
elevation of point
B?
Lab #4 Map Fundamentals and Interpretation
In this lab, maps will be introduced as important geographical tools. To use maps properly,
one must know the basic rules and limitations of maps. This lab will have three parts: the first
is an introduction to maps including exercises on map scale; the second part is an exercise to
acquaint yourself with the assigned atlas, and the third is an introduction to topographic
maps.
Pre-lab reading topics: map projections, map scale, latitude and longitude, topographic
maps.
WHAT ARE MAPS?
Maps are graphical representations of reality. They are two-dimensional depictions of
the Earth's surface, which geographers use to portray surface structures or the
distributions of geographic phenomena.
1a). What two subclasses of maps are there?
1b). Give an example of a thematic map.
MAP FUNDAMENTALS / LIMITATIONS:
Maps can be extremely useful tools, a good strategy for understanding maps is to identify
and read the basic elements. In general most maps should have the following: write a
definition for each.
2a) Title
2b) Scale
2c) Legend
2d) Direction
2e) Grid
2f) What is a cartographer?
2g) What are the advantages and disadvantages of a globe?
2h) What are projections?
2i) Name three types of projections.
MAP SCALES
Maps have scales which tell the map reader the difference between map realities and
actual (terrestrial) realities: scale should be thought of as the ratio between map and Earth.
Scale = Distance On Map
Distance On Earth
3a). There are three types of map scales; they are
1)
2)
3)
Convert the following map scales:
Fraction)
V = Verbal
R= Ratio (Representative
3b) (V-R) One inch to one mile
__________:___________
3c) (V-R) One cm to one km
__________:___________
3d) (R-V) 1:50,000
________cm to__
km
3e) (R-V) 1:126,720
___
mi
in to
___
THE EARTH'S GRID
To allow for the accurate location of places, a system of lines is superimposed over the
Earth's surface. Lines of longitude are called meridians and lines of latitude are called
parallels. These lines serve as a coordinate system which helps navigation and understanding
the Earth. Refer to pages 6-8 in your atlas.
4a) What parallel divides the Northern and Southern Hemispheres?
4b) Meridians run in what direction?
Where do they converge?
4c) The Prime Meridian passes through what city?
What longitude is it? _______º
4d) Lines of latitude run in what direction
to each other.
___________________
and are
4e) Latitude refers to the arc, measured in degrees, of a meridian measured between
________________________________________________.
4f) Longitude measures the degrees
Meridian.
or
from the Prime
HAMMOND'S ATLAS EXERCISE
5a) What is the area (km²) ______________ population ________________, and population
density (number of people/km²) _______________ of Namibia? (pg. 9). Please show your
work.
5b) Use your map index to determine the latitude of:
Baghdad, Iraq
Los Angeles, California
Which city is further north?
5c) Use your map index to determine the longitude of:
Kuwait City
Moscow, Russia
Which city is further east?
5d) In Nairobi, the average monthly temperature in January is ____________, and the
average monthly temperature in July is _______________.
5e) Calculate the temperature range by subtracting the value for July from the value for
January. The January to July temperature range is ________________.(pg. 66)
5f) What two tectonic plates are separated by the San Andreas fault (pg 14)?
5g) What ocean current is found off the west coast of the U.S?________________________
Is it warm or cold?_____________________________________
Which direction does it flow?______________________________ (pg. 16)?
TOPOGRAPHIC MAPS
One of the most common types of maps found in the study of physical geography is the
topographic or contour map, which is an isarithmic map showing changes in elevation across
the landscape. This section will introduce isarithmic maps in general, and will provide
experience in working with topographic maps.
6a) What is an isoline?
6b) Isolines connecting points of equal temperature are called
.
6c) Isolines connecting points of equal precipitation are called
.
6d) Isolines connecting points of equal pressure are called
.
6e) Isolines connecting points of equal elevation are called
.
In the next three sections you will be doing exercises related to topographic
contour maps. Topographic maps are used by hikers and campers as an aid in
following roads and trails in recreational areas. In physical geography, the
topographic contour map is used to gain information about the earth's surface
through contour lines that show the shape and elevation of terrain.
3 DIMENSIONAL TOPOGRAPHIC MODELS
Use the white, 3-Dimensional Topographic Models provided to answer the questions in
this section. These models show contour lines, raised relief and a combination of both. Be
sure to record the proper units of measurement
7a) What is the contour interval for this map? (Hint: Look at bottom left of the
picture)
_____________.
7b) What is the highest elevation on the map? (Hint: Look a few inches above point
L)
_____________.
7c) What is the change of elevation over the interval O? (Hint: Count from tip of one
arrow to tip of the other arrow)
_____________.
7d) What is the elevation of the tower in grid 45.74 and 5.84? (Hint: it’s between
point O and point C)
_____________.
7e) What is the horizontal distance in meters between peaks D & G? (Hint: the
measurement is 9cm) ___________.
TOPOGRAPHIC MAP INTERPRETATION
Answer the following questions using the topographic contour map provided on
the following page. Be sure to include units of measurement. Estimates are the range
between two known elevations. Ex. 1000-1025 m.
8a) What is the contour interval used on this map?
8b) What is the elevation of the contour at point A?
8c) What is the elevation of the contour at point B?
8d) Estimate the elevation of the summit point C.
8e) Estimate the elevation of point D.
8f) Give the elevation of the hachured depression at point E
8g) Calculate the area in km² (Hint: 1 km² = 1 million m²) of the hachured
depression referred to in the previous question (the area of the hachured depression is
1.5 cm²). Please show your work.
8h) Estimate the elevation at the bottom of the depression at point F
8i) How do you know that point F is a depression and not a summit?
8j) Measure the horizontal distance between points C and D (Hint: Distance is 5 cm,
make sure to convert and use the scale provided on map)
8k) What is the difference in elevation between C and D
8l) Calculate the average slope from C to D (Hint: Slope = rise / run, so Slope =
Answer from k/Answer from j)