Chapter 2 Flashcards
Elevation
the height above sea level of a point on the earth’s surface
relief
the difference in elevation between the highest parts of an area
landform
a feature of topography, such as a hill or valley, formed by the processes that shape the earth’s surface.
landform region
a large area of land where the topography is made up mainly of one type of landform. The Great Plaines and Rocky Mountains are examples
map
a flat model of all or part of the earth’s surface as seen from above
globe
a sphere that represents earth’s entire surface
scale
measures distance on a map to a distance on the earth’s surface
symbols
shapes and pictures used on a map to stand for features on the earth’s surface
key
a list of all the symbols used on the map with an explanation of their meaning
What are two of the main lines that make up the grid for measuring the Earth’s surface
the Equator and the Prime Meridian
degree
degrees are used to measure the distance around a circle and are the unit of measure that scientists use to locate positions on the earth’s surface
Equator
The equator is an imaginary line that circles the earth’s surface. It is halfway between the North and South Poles. It divides the Earth into the Northern and Southern Hemispheres. The Equator is the starting point for measuring Latitude.
hemisphere
One-half of the sphere that makes up the earth’s surface
Prime Meridian
An imaginary line that makes a half circle from the North Pole to the South Pole. It passes through Greenwich, England. Places East of the Prime Meridian are in the Eastern Hemisphere. Places West of the Prime Meridian are in the Western Hemisphere.
Latitude
The distance North or South of the equator (counted in degrees). The latitude of the Equator is 0 degrees. Between the Equator and each Pole are 90 evenly spaced, parallel lines called lines of latitude. Each degree of latitude is about 111 kilometers.
Longitude
The distance in degrees East or West of the Prime Meridian. There are 360 lines of longitude that run from north to south and they meet at the Poles. A degree in longitude equals about 111 kilometers at the Equator, but at the Poles the distance decreases to zero. The Prime Meridian is the starting line for measuring longitude and is at 0 degrees. The lines of longitude in each hemisphere are numbered up to 180 degrees.
Map Projection
a framework of lines that helps in transferring points on Earth’s three-dimensional surface onto a flat map
Name 3 common map projections
Mercator Projection
Equal Area Projection
Conic Projection
Describe a Mercator Projection map
All the lines of longitude and latitude appear as straight and parallel lines that form a rectangle. The size and shape of landmasses near the Equator are distorted only a little but become more distorted at the Poles. This is because the lines of longitude do not come together at the poles.
Describe an Equal Area Projection Map
This map correctly shows the relative sizes of Earth’s landmasses, but it has a distortion at the edges of the map. The shapes of the landmasses at the edges of the map appear stretched and curved.
Describe a Conic Projection Map
The lines of longitude appear as straight lines, while the lines of latitude are curved. There is little distortion on the conic maps. They are used to show limited parts of the earth’s surface (like a map of just the USA).
Surveying
How mapmakers determine distances and elevations using instruments (tools) and the principles of geometry
digitizing
The process by which mapmakers convert the location of map points to numbers
Satellite Images
pictures of the earth’s surface taken by satellites in space
pixels
thousands of tiny dots that make up a satellite image
Global Positioning System
A method of finding longitude, latitude, and elevation of points on Earth’s surface using a network of satellites
topographic map
a map showing the surface features of the earth’s surface. They use symbols to portray the land as if you were looking down on it from above. They provide highly accurate information on the elevation, relief and slope of the ground surface
contour line
connects points of equal elevation on a topographic map
contour interval
the change in elevation from one contour line to another on a topographic map
index contours
Usually every 5th contour interval line on a topographic map is an index contour. They are darker and heavier than the contour interval lines. They are labeled with the elevation in round units such as 2,000 ft. above sea level.
How are topographic maps used
They are used to design safe highways, to help businesses decide where to build new stores, to help governments select places for new public buildings, and help people plan trips.
