Locations on Earth
What is cartography?
The art and science of making maps
Describe the shape of the earth
The Earth is not a perfectly round sphere
The Earth is a flattened (oblate) sphere.
What is a map scale? What is a map legend?
Map Scale - the ratio between a length on a map and the corresponding horizontal distance on the ground.
Legend - a key on a map that indicates what each symbol represents
What are lines of latitude? What is the highest and lowest degree that they can be?
latitude is the angle between lines
drawn from the center of the Earth
to the surface, north or south of
the equator
Lines of latitude are parallel
and are the same distance
apart.
Latitude varies from 0° (equator)
to 90° (north or south pole)
Why is it necessary to use projections when making a map of the world?
Maps are two-dimensional (flat)
representations of a three
dimensional (curved) surface showing natural or man-made feature
The true sizes, shapes, and angles of Earth features will be distorted on flat maps.
Different types of map projections attempt to minimize distortions.
What are contour lines used for on topographic maps?
- connect points of equal elevation
- closer together the steeper the elevation
What is longitude? What is the highest and longest degree that it can be measured?
the angle east or west of
a 0° line running from the north
pole to the south pole (called the
prime meridian)
Lines of longitude are called
meridians and are closer
together at the poles than at the
Equator.
They range from -180 to +180 degrees.
Describe cylindrical projections. What are they used for? Where are they most distorted?
Commonly used for world maps.
Earth’s surface features are projected on a cylinder wrapped around the equator.
Accurate near the equator but distorted near the poles
Name at least 3 types of electromagnetic waves (we learned 6)
Long Wavelength/Low Energy - Radio Waves
Infrared (heat)
Visible Light (photography)
Ultraviolet (or “black light”)
X-Rays
Short Wavelength/High Energy - Gamma Rays
Explain what GPS is
The United States has a fleet of satellites (currently 3,415 operational) in Earth orbit
At any moment, at least four satellites are in the sky over any location
This way, precise locations on earth can be calculated.
Describe Conic projections. What are they used for? Where are they most distorted?
Commonly used for mapping something like a country or continent.
Cone-shaped
Features toward the top and bottom of the map are distorted.
How can remote sensing be helpful for us to use?
Recording infrared along with visible light helps to show changes in plants/soil that we couldn’t see with visible light
Remote-sensing can tell us new things about the weather, such as when storms develop anywhere in the world, and lots of other small details about the climate
What continent exists between 0 and 180 degrees west and 0 and 90 degrees north
North America!
Describe azimuthal projections. What are they used for? Where are they most distorted?
Earth’s surface is mapped to a plane that touches the globe at one point
The features at that point are not distorted, but distortion gets worse the farther from the point.
Commonly used for mapping the North and South Poles.
Name the primary system that makes maps today, and what kind of information that system contains
Geographic Information Systems (GIS)
Imagery (photographs or satellite pictures)
Elevation data
Representations of land features like road, lakes, rivers, political boundaries