Using Maps and Mapping Technology. Map Projections Video Clip (approx 3 min)Video Clip An attempt to...
-
Upload
sheryl-walton -
Category
Documents
-
view
213 -
download
0
Transcript of Using Maps and Mapping Technology. Map Projections Video Clip (approx 3 min)Video Clip An attempt to...
Using Maps and Mapping Technology
Map Projections
• Video Clip (approx 3 min)
• An attempt to portray the round - “spherical” Earth on a flat surface– Creates large areas of
distortions
• There are three common projections
Mercator Projection
• Features of Earth depicted in the form of a cylinder, stretched out on paper – usually a rectangular map
• Most accurate at point of contact – the equatorial areas
• Distortions away from point of contact - near the poles
Conic Projection
• A way of mapping the Earth in the shape of a cone ---point of cone situated directly over one of the poles
• A “birds-eye view” of the Earth
• Most accurate at point of contact - mid-latitudes
• Distortions away from point of contact - poles and equatorial areas
Polar Projection
Portraying Earth or a portion of the Earth in a circular map
Most accurate at point of contact – the poles
Distortion further from the point of contact – mid-latitudes or equatorial area
Topographic Map• Shows surface surface
featuresfeatures or topographytopography of the Earth
• Shows – natural and artificial
features (fields, forests, rivers, lakes, glaciers, buildings, roads, power-lines, etc.
– elevation (with brown contour lines)
• Little to no distortion• Much more later!
Satellite Imagery
• Photographs made by means of artificial satellites
• Most often used:– To predict weather
on Earth– To help create
maps of the seafloor, other planets, topography, etc.
– Military intelligenceTyphoon near Japan
Satellite Image of Earth At Night
Satellite Image of Ocean Depth
Satellite Image – Gulf Oil Spill
GPS “Global Positioning System”
Problems with GPS
• Works poorly in the following areas:– Dense forest– Deep canyons– Caves– Underwater
Latitude & Longitude
Latitude
• Horizontal/parallel lines on a globe or map
• Measure north or south of the equator
• AKA – Parallels
On a map latitude looks like this…
equator
Examples:
• What line of latitude runs through Canada?
equator
Examples:
• What line of latitude runs through Florida?
equator
Longitude
• Vertical lines on a globe or map• Measures east or west of the prime meridian• AKA - Meridians
On a map longitude looks like this…
Prim
e m
erid
ian
Inte
rnat
iona
l Dat
e Li
ne
Examples
• What is the longitude for the middle of S. America?
Prim
e m
erid
ian
Inte
rnat
iona
l Dat
e Li
ne
Examples
• What is the longitude for California?
Prim
e m
erid
ian
Inte
rnat
iona
l Dat
e Li
ne
Putting it together…• What are the coordinates for the following
– X– Y– Z
z
yx
PM
EQ
IDL
Map Scales
• Verbal Scale– Example 1 inch = 1 mile
• Representative Fraction (R.F.)– Example 1:24,000 (1 map unit is
equivalent to 24,000 land units.)
• Graphic Scale– Example
Map Symbols