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Mapping Earth’s Surface
Table of Contents
Exploring Earth’s Surface
Models of Earth
Topographic Maps
8.1 Vocabulary
•Topography
•Elevation
•Relief
•Landform
•Plain
•Mountain
•Mountain range
•Plateau
•Landform region
What does the topography of an area include?
•The topography of an area includes the
area’s elevation, relief, and landform.
•Elevation is the height above sea level at a
specific point on the Earth’s surface.
•Relief is the difference between the highest
point and lowest point of a region.
•Landform is created by the processes that
shape the Earth’s surface.
Exploring Earth’s Surface
Lewis & Clark’s Journey
The route of the Lewis and Clark expedition crossed regions that differed
greatly in elevation and relief. Which are the highest and lowest points on
their route?
Exploring Earth’s Surface
What are the main types of landforms?
Landforms
Plains, mountains, and plateaus are three of the
many landforms that make up the topography of Earth’s surface.
Plains
•A plain that lies along a seacoast is called a
coastal plain, with low elevation and low
relief and extends around the eastern and
southeastern shores.
•A plain that lies away from the coast is
called an interior plain, with varying
elevations. The broad interior plains are
called the Great Plains.
Mountains
•Mountains have high elevation and high
relief.
•Mountain ranges and mountain systems in
a long, connected chain form a larger unit
called a mountain belt.
•The Rocky Mountains stretch down the
western side of North and South America.
Plateaus
•A plateau will have high elevation with a
more or less level surface.
•A plateau is rarely perfectly smooth on top.
Streams and rivers may cut into the surface
creating varied elevation.
Exploring Earth’s Surface
Landform Regions
All of the land in one major landform region tends to have
much in common.
Highest elevation in US is Mt. McKinley (6,194m) and lowest elevation
Death Valley (-86m).
Models of Earth
Measuring Earth
What science skills did Eratosthenes use to estimate the Earth's
circumference?
8.2 Vocabulary
•Globe
•Map
•Map projection
•Symbol
•Key
•Scale
•Degree
•Equator
•Hemisphere
•Prime meridian
•Latitude
•Longitude
How do maps & globes represent Earth?
•Both maps and globes show the shape, size,
and position of features on Earth’s surface.
•Maps are 2-D representations while globes are
3-D representations and always represent the
whole Earth.
•Maps and globes are drawn to scale and use
symbols to represent features on Earth’s
surface.
•To show Earth’s curved surface on a flat map,
cartographers use map projection.
Map projection
•While trying to portrait Earth’s features on to a
map, continents, oceans, & islands may have
distorted shapes and sizes depending upon the
type of projection used.
•A Mercator projection is based on Earth’s
features projected onto a cylinder that encircles
the Earth at the equator.
•The size and shape of landmasses at the
poles are more distorted, but are more accurate
near the equator..
Models of Earth
Mercator Projection
A Mercator projection is
based on a cylinder with
grid lines that has been
flattened.
What’s in a map?
•A map may show the whole Earth or just
part of the earth.
•A map uses symbols explained in a key,
and usually has a compass rose to show
direction. Often north is shown at the top of
the map.
•A scale is often given as a ratio showing the
relationship between the distance on the
map to the distance on the Earth’s surface.
Models of Earth
What’s in a Map?
A map uses symbols
explained in a key, and
usually has a compass rose
to show direction. A scale is
often given as a ratio
showing the relationship
between the distance on
the map to the distance on
the Earth’s surface.
Google Maps
How is distance measured in degrees?
• To help find places on the Earth’s surface, a
grid is created that curves to cover the entire
planet.
• Distances on Earth are measured in degrees
from the equator and the prime meridian.
• On Earth’s surface, degrees are a measure
of an angle formed by lines drawn from the
center of Earth to points on the surface.
• To locate points precisely, degrees are
further divided into smaller units called
minutes and seconds.
• There are 360º in a circle, 60’ (minutes)
in a degree, 60” (seconds)in a minute
Models of Earth
Degrees Around
Distances around a circle
are measured in degrees,
minutes, and seconds.
Equator
•Half way between the north pole and south
pole is the imaginary line that circles the
Earth at the widest part.
•It divides the Earth into the Northern and
Southern hemispheres.
Prime Meridian
•Another imaginary line that makes a half
circle from the North Pole to the South Pole
through Greenwich, England is the Prime
Meridian.
•Places west of the Prime Meridian are in
the Western Hemisphere while to the east is
the Eastern Hemisphere.
•On the other “side” of the Prime Meridian is
the International Date Line.
Models of Earth
Equator and Prime Meridian
The equator and prime meridian divide Earth’s surface into hemispheres.
What are latitude and longitude?
•The grid on the Earth is created by lines of
latitude and longitude.
•The equator is the starting line for
measuring latitude, 0° and measures to
each pole, 90°N at the North Pole, 90°S
at the South Pole.
•Each line of latitude is parallel to one
another, about 111km apart.
•There are 360° of longitude that run from
north to south meeting at the poles.
•Each line is about 111km apart at the
equator, but at the poles, the lines come
together to 0km.
•The Prime Meridian, which is the starting
point, is at 0° and numbered to 180° at
the International Date Line.
Models of Earth
Latitude and Longitude
Points on Earth’s surface can be located
using the grid of latitude and longitude
lines.
•The location of any point on Earth’s surface
can be expressed in terms of the latitude
and longitude lines that cross a that point.
•Each longitude line crosses the latitude
lines, including the equator, at a right angle.
•Lines of latitude (N-S) are given first, then
lines of longitude (E-W).
Models of Earth
Interpret Maps
Every point on Earth’s surface has a particular latitude and longitude.
8.3 Vocabulary
•Contour line
How do maps who topography?
•Topographic maps portray the land as if you
were looking down on it from above.
•Contour lines connect points of equal
elevation and show the relief and slope of
the ground.
•The change between contour lines is the
contour interval and given in the map key.
•Every fifth contour line is an index contour,
a darker line to help read the elevation.
Topographic Maps
To read a topographical map,
begin at the labeled index
contour. Then count the
number of contour lines up or
down to the feature. Closely
spaced lines indicate steep
slope, a change of height over
a short distance. Widely
spaced lines indicate gentle
slopes. A closed loop
indicates a hilltop, but with
dashes inside, indicates a
depression in the ground. Vshaped lines pointing downhill
indicate a ridge line while
pointing uphill indicate a
valley. A stream may flow
toward the open end of the V.
Topographic Maps
Mapping a Mountain
How is a map a model of
Earth?
Topographic Maps
Topographic Map
What feature is shown by this map?