Earth & Space Science
Chapter 3: Models of the Earth
Section 1: Finding Locations on Earth
I.
Latitude
 The points at which Earth’s axis of rotation intersects Earth’s surface are used as __________
points for defining direction. These points are the geographic ________________ and South Pole.
 Halfway between the poles, a circle called the ____________ divides Earth into the North and
Southern Hemispheres.
 A reference grid that is made up of additional __________ is used to locate places on Earth‘s
surface.
 One set of circles describes positions north and south of the equator. These circles are known as
_______________, and they express latitude.
 parallel any circle that runs ____________________________ around Earth and that is parallel
to the equator; a line of latitude
 latitude the angular distance ____________________ from the equator; expressed in degrees
Degrees of Latitude
Latitude is measured in degrees, and the equator is 0° latitude. The latitude of both the
North Pole and the South Pole is _____°.
Minutes and Seconds
Each degree of latitude consists of 60 equal parts, called ____________. One minute
(symbol: °) of latitude equals 1.85 km.
In turn, each minute is divided into 60 equal parts, called ____________ (symbol: °).
II.
Longitude

East-west locations are established by using _________________.

meridian any semicircle that runs north and south around Earth from the geographic North
Pole to the geographic South Pole; a line of _________________

longitude the angular distance _______________________ from the prime meridian;
expressed in degrees
Degrees of Longitude

The meridian that passes through Greenwich, England is called the
______________________. This meridian represents 0° longitude.

The meridian opposite the prime meridian, halfway around the world, is labeled _____°,
and is called the International Date Line.
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Earth & Space Science
Distance between Meridians

The distance covered by a degree of longitude depends on ___________the degree is
measured. The distance measured by a degree of longitude decreases as you move from
the equator toward the poles.
III.
Great Circles
A great circle is any circle that divides the globe into__________________, or marks the
circumference of the globe.
Any circle formed by two meridians of longitude that are directly across the globe from each
other is a __________________________.
The equator is the _______________ line of latitude that is a great circle.
The route along a great circle is the shortest distance between two points on a sphere. As a
result, great circles are commonly used in navigation, such as for __________ and _________
routes.
IV.
Finding Direction

One way to find direction on Earth is to use a magnetic __________________.

A magnetic compass can indicate direction because Earth has magnetic properties as if a
powerful bar-shaped _________________were buried at Earth’s center at an angle to Earth’s
axis of rotation.

The areas on Earth’s surface just above where the poles of the imaginary magnet would be
are called the _______________________________________.

The geomagnetic poles and the geographic poles are located in different places.
Magnetic Declination
The _______________ between the direction of the geographic pole and the direction in
which the compass needle points is called magnetic declination.
In the_______________ Hemisphere, magnetic declination is measured in degrees east
or west of the geographic North Pole.
Because Earth’s magnetic field is constantly changing, the magnetic declinations of
locations around the globe also ___________________ constantly.
By using magnetic declination, a person can use a compass to determine geographic
_______________for any place on Earth.
The Global Positioning System

Another way people can find their location on Earth is by using the global positioning
system, or _______________.
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Earth & Space Science

GPS is a satellite navigation system that is based on a global network of __________
satellites that transmit radio signals to Earth’s surface.

A GPS receiver held by a person on the ground receives signals from ________ satellites
to calculate the latitude, longitude, and altitude of the receiver on Earth.
******Section 2: Mapping Earth’s Surface******
I.
How Scientists Make Maps
Because most globes are too small to show _______________ of Earth’s surface, such as
streams and highways, a great variety of maps have been developed for studying and displaying
detailed information about Earth.
The science of making maps is called _______________. Scientists who make maps are called
cartographers. Cartographers use data from a variety of sources, such as from field surveys and
remote sensing.
remote sensing the process of gathering and analyzing information about an object without
_______________________ being in touch with the object
II.
Reading a Map
Maps provide information through the use of ____________________.
Direction on a Map

Maps are commonly drawn with ____________ at the top, ____________at the right,
___________at the left, and _____________ at the bottom.

Some maps use parallels of latitude and meridians of longitude to indicate
________________ and location.

Many maps also include a ________________, which is a symbol that indicates the cardinal
directions (north, east, south, and west), or an arrow that indicates north.

Draw a picture of a compass rose below here:
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Earth & Space Science
Symbols

________________ are commonly used on maps to represent features such as cities,
highways, rivers, and other points of interest.

Symbols may ____________ the features that they represent, or they may be more abstract.

Symbols are commonly explained in a legend. A ____________ is a list of map symbols and
their meanings
Map Scales
A __________ shows the relationship between the distance shown on a map and the actual
distance
Map scales are commonly expressed as ____________ scales, fractional scales, or verbal scales.
A ________ scale is a printed line that has markings that represent units of measure,
such as meters or kilometers.
A ________ scale is a ratio that indicates how distance on Earth relates to distance on
the map.
A ________scale expresses scale in sentence form.
Isograms
An isogram is a_______on a map that represents a constant or equal value of a given quantity
The second part of the word, ___________, can be changed to describe the measurement being
graphed. For example, when the line connects points of equal temperature the line is called an
isotherm. When the line connects points of equal atmospheric pressure, the line is called an
isobar.
Isograms can be used to plot many types of data, such as atmospheric pressure,
____________________, precipitation, gravity, magnetism, density, elevation, chemical
composition, and many others.
******Section 3: Types of Maps******
I.
Topographic Maps
One of the most widely used maps is called a topographic map, which shows the ____________
features of Earth.
_________ refers to the size and shape of the land surface features of a region
________ refers to the height of an object above sea level
Advantages of Topographic Maps
Topographic maps provide more __________ information about the surface of Earth than either
drawings.
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Earth & Space Science
Elevation on Topographic Maps
On topographic maps, elevation is shown by using __________ lines. A contour line a line that
connects points of equal ___________ on a map
The difference in elevation between one contour line and the next is called the contour
__________. The contour interval is selected based on the relief of the area being mapped.
____________the difference between the highest and lowest elevations in a given area
Every fifth contour line is darker than the four lines one either side of it. This
________________ makes reading elevation easier.
Landforms on Topographic Maps
The __________ and direction of contour lines indicate the shapes of the landforms represented
on a topographic map.
Closely spaced contour lines indicate that the slope is ___________.
Widely spaced contour lines indicate that the land is relatively __________.
A contour line that bends to form a _________ shape indicates a valley.
Contour lines that form ____________ indicate a hilltop or a depression.
Topographic Map Symbols
Symbol color indicates the type of feature. Constructed features, such as buildings, are shown in
_________. Highways are shown in __________. Bodies of water are colored _________, and
forested areas are colored ____________.
Contour lines are brown or _________.
II.
Geologic Maps
Geologic maps are designed to show the __________ of geologic features, such as the types of rocks
found an a given area and the locations of faults, folds, and other structures.
Rock Units on Geologic Maps
On geologic maps, geologic units are distinguished by color. Units of similar ages are generally
assigned colors in the same color family, such as different shades of __________________.
In addition to assigning a color, geologists assign a set of ____________ to each rock unit. This
set of letters symbolizes the age of the rock and the name of the unit or the type of rock.
Other Structures on Geologic Maps
Other markings on geologic maps are contact lines. A ____________ indicates places at which
two geologic units meet, called contacts.
The two main types of contacts are _________ and depositional contacts.
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Earth & Space Science
Geologic maps also indicate the strike and slip of rock beds. __________indicates the direction
in which the beds run, and _________ indicates the angle at which the beds tilt.
III.
Soil Maps
Scientists construct soil maps to classify, map, and describe soils, based on surveys of soils in a
given area.
Soil Surveys
A soil survey consists of three main parts: ______, maps, and _________.
The text includes general information about the geology, topography, and __________ of the
area.
The tables describe the ________ and volumes of soils in the area.
The maps show the approximate ___________ and types of the different soils.
Uses of Soil Maps
Soil maps are valuable tools for ________________ and land management.
Soil maps are used by ___________, agricultural engineers, and government agencies.
The information in soil maps and soil surveys helps developers and agencies identify ways to
____________ and use soil and plan sites for future development.
IV.
Other Maps
Maps are useful to every _________ of Earth science.
Maps that show topography and rock and soil types are only ______ useful type of map.
Some Earth scientists use _________ to show the location and flow of both water and air.
Other types of Earth scientists use maps to study _________ in Earth’s surface over time.
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