Transcript File landforms&mapping

Landforms & Mapping
Earth Science
Landforms
A feature that makes up the shape of
the land at Earth’s surface
3 basic types
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Plains - large relatively flat areas
Plateaus – relatively flat raised areas
Mountains- raised areas
Plains
Coastal plains
Broad areas along
the oceans shore
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Ex. Atlantic Coastal
Plain - low rolling
hills, swamps, and
marshes
Marsh – grassy
wetland usually
flooded with water
Interior Plains
Make up much of
the central portion
of the US.
Extend from the
Appalachian
Mountains to the
Rocky Mountains.
Plateaus
Relatively flat, raised areas of land.
Different from plains because they rise
steeply from the ground around them.
Ex. Colorado Plateau – lies west of the
Rocky Mountains. The Colorado River
runs through it, forming the Grand
Canyon.
Mountains
Folded Mountains
Form when rock
layers are squeezed
from opposite sides.
Ex. Appalachians
Mountains: 2
Upwarped
Mountains
Form when crust is
pushed up by forces
inside the Earth.
Ex. Rockies & Black
Hills
Mountains: 3
Fault-Block
Mountains
Form when huge
tilted rocks are
separated from
surrounding rock by
faults.
Ex. Grand Tetons &
Sierra Nevada
Mountains: 4
Volcanic Mountains
Form when molten
material reaches the
surface and it piles
up.
Ex. Mount St. Helens
& Mauna Loa
Latitude
Latitude refers to distance north or
south of the equator.
The equator is numbered as 0° latitude.
The poles are each numbered 90°.
Locations North of the equator are in
north latitude and south of it are on
south latitude
Longitude
Run north and south around the globe.
The Prime Meridian is considered to be
0° longitude
All other longitude is measured from
there.
Longitude goes from 0° to 180°
The International Date Line is at 180°
longitude.
Time Zones
Earth is divided into
24 different time
zones.

Each Time zone is 15
degrees (longitude)
wide.
The US has 6
different time zones.
International Date
Line
Maps
Maps are all models of some area.
Maps of the world are commonly made
using projections.
A projection is made when points an
lines on a globe are transferred onto
paper.
All projections contain some type of
distortions.
Mercator Projection
Has the correct
shape of the
continents, but their
areas are distorted.
When longitude
lines are made
parallel, the areas
near the poles are
exaggerated.
Robinson Projection
Has accurate shapes and shows accurate
land mass.
Areas near the pole suffer less distortion.
Conic Projection
Used to produce
maps of small areas.
Project points and
lines from a globe
onto a cone.
Topographic Maps
Shows the changes in elevation of the
Earth’s surface.
Shows features such as mountains,
plains, lakes, as well as roads, cities,
etc…
Allows you to tell how steep a mountain
is or how deep a valley.
Contours
Contour line –
connects points of
equal elevation.
Elevation – distance
below or above sea
level.
The difference in
elevation between
side-by-side contour
lines is the contour
interval.
Contour lines
marked with their
elevation are index
contours
Rules of Contour lines
Contour lines close around hills and
basins. (hachures point down)
Contour lines never cross.
Contour lines form Vs that point
upstream whenever they cross streams.
What if my contour lines are
close together?
If the contour lines are close together,
then that indicates that area has a
steep slope.
What if my contour lines are far
apart?
If the contour lines are far apart, then
that indicates the land has a gentle
slope (low slope).
What do the dark colored contour
lines mean?
The dark colored contour lines
represent every fifth contour line to
make it easier to read the map.
What do depressions in the map
look like?
A depression, such as the inside of a dead
volcano, is represented by Hachure lines.
Hachure lines are regular contour lines with
small segments sticking out from it.
The first hachure line is at the same elevation
as the contour line before it.
More on Contour Lines
Contour lines form V’s that point
upstream when they cross a stream.
It is important to remember that they
point in the opposite direction as the
flow of water.
What do the colors on the
topographic map represent?
Blue lines/shapes - represent water
features, such as streams and lakes.
Brown – contour lines
Black – Roads, buildings, railroads,
other man made objects.
Green – Woodland areas
Red - Highways
Now that I know what a
topographic map is, how do I
read it?
First determine the contour interval (the
distance between each contour line)
Then determine the map scale (usually at
the bottom of the map)
Identify any hills or depressions
Use the legend to identify man made
features.
Reading a topographic map cont.
Look for areas where the contour lines
are close together – they indicate a
steep area.
Look for areas where the contour lines
are spread apart – they indicate a
gentle slope.
Legend and Scale
Map legend explains
what the symbols
used on the map
mean.
Map scale is the
relationship between
distances on the
map and actual
distances on the
Earth’s surface.
Scale is often
expressed as a ratio
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1:500 means 1 unit
on the map = 500
units on the Earth.
Mapping our Planet
Maps of the world can be made in several
ways.
Most maps today are made using satellites.
Maps of the ocean floor can be made using
sonar.
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The Sea Beam is a very advanced type of sonar
device.
Satellites
Landsat – detects different wavelengths
from Earth’s surface and changes them
into color.
Topex-Poseidon – Uses radar to find the
distance to the oceans surface and plot
maps of the ocean floor.
GPS (Global positioning System) – allows
a user to determine their exact position
anywhere on Earth.
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Has 24 satellites in orbit