Just like in math class degrees are used to measure angles circle, degrees are used to determine locations of points on earth. A degree of latitude is approximately 69 miles, and a minute of latitude is approximately 1.15 miles. A second of latitude is approximately 0.02 miles, or just over 100 feet. A degree of longitude varies in size. At the equator, it is approximately 69 miles, the same size as a degree of latitude. The size gradually decreases to zero as the meridians converge at the poles. At a latitude of 45 degrees, a degree of longitude is approximately 49 miles. All of N.Y.C. will have the same latitude and longitude degrees but the minutes and seconds are unique between buildings.
The International Meridian Conference was a conference held in October 1884 in Washington, D.C. , in the United States to determine the Prime Meridian of the world. The conference was held at the request of U.S. President Chester A. Arthur. Prime meridian is arbitrary…difft countries had in different place throughout time ex. France had it in Paris, etc. Now it is standardized. Greenwich is a town near London. There is a famous observatory there. The subject to discuss was the choice of «a meridian to be employed as a common zero of longitude and standard of time reckoning throughout the world
Draw a compass rose on the board…make sure students know the difference between East and West
Artist’s Representation of Space Trash 14.1 degrees south latitude and 170.2 west longitude. http://abcnews.go.com/Technology/space-satellite-uars-adrift-heading-earth/story?id=14534076
Ask: Why would a topo map be useful in determining where to build an airport?
Contour lines can never cross one another. Each line represents a separate elevation, and you can’t have two different elevations at the same point. The only exception to this rule is if you have an overhanging cliff or cave where, if you drilled a hole straight down from the upper surface, you would intersect the earth’s surface at two elevations at the same X,Y coordinate. In this relatively rare case, the contour line representing the lower elevation is dashed.
Maps, Globes, and how to read them:• Maps and globes are drawn to scale.• Scale - relates distance on a map to distance on the earth’s surface.
Scale-Three Types:1. Ratio Scale: For example, one unit on a map could equal 100,000 units on the ground.2. Bar Scale: is a line drawn on a map of known ground length.3. Equivalent Units Scale: states what distance on a map is equal to what distance on the ground
• To locate points on a map or globe, we use the equator, the prime meridian, and longitude and latitude lines.• The units in which points are measured are in degrees (angular distances calculated from the center of the Earth)• To give an exact location, a degree can be broken down into 60 minutes, and a minute broken down into 60 seconds.
• The earth is divided into lines called latitude and longitude.
• Longitude lines run vertically (north and south.)• Latitude lines run horizontally (east and west.) *LATitude is FLAT, LONGgitude is LONG* Lo ng itu de L a ti tu d e
• The equator is an imaginary line that runs HALFWAY BETWEEN the North Pole and the South Pole. It is 0 degrees latitude.• The equator divides the earth into a northern and a southern hemisphere. Equator
• The prime meridian is an imaginary line that runs FROM the north pole to the south pole. It is 0 degrees longitude.• The prime meridian divides the earth into eastern and western hemispheres.
•There is a markershowing the actuallocation of the PrimeMeridian in Greenwich,England.
Prime Meridian N •Lat/Long are 2 grid points or coordinates by which you can locate any point onW E earth! Equator •The four quarters of a world map can be designated by S North or South and East or West.
•N tells us we’re north(N, W) (N, E) of the Equator. S tells us we’re south of the Equator. •E tells us that we’re east of the Prime Meridian. W tells us that (S, W) (S, E) we’re west of the Prime Meridian.
•Latitude is90°N Y always measured in degrees North or X South because it is either north or south of the equator. 90°S
Y• Longitude is always measured in degrees East X or West because it is East or West of the prime meridian. 180°W 180°E
(N, W) •That means all points in North America will have a North latitude and a West longitude because it is North of the Equator and West of the Prime Meridian. Prime Meridian
•What would be the latitude and longitude directions in Australia?Prime Meridian ? Latitude: º South Longitude: º East!
Long or Lat?•Is 30º East a Longitudeor Latitude?Longitude•Is 60º South a Longitudeor Latitude?Latitude
Which Quarter are These Lon/Lats Located In? 0 degrees latitude = equator 1. 41°N, 21°E 1. B 2. 37°N, 76°W 2. A 3. 72°S,141°W 3. CA B 4. 7°S, 23°W 4. C 5. 15°N, 29°EC D 5. B 6. 34°S, 151°E 6. D 0 degrees longitude = prime meridian
• For centuries, maps were drawn by hand.• Mapmakers determined distances and elevation using instruments in a process called surveying.• Now, computers are used to make maps.• Where do computers get the information to make maps?
• Satellites that orbit the earth obtain information which assists with mapping (finding elevation, latitude longitude, and ground covering), measure environmental change, determine urban growth, etc.• The Landsat satellite program began in 1972.• Landsat satellites collect information which is used to make Landsat satellite digital satellite images.
• Landsat satellites record radiation from the surface of the earth in different wavelengths of the electromagnetic spectrum. Much of this radiation we cannot see (ex. infrared).• Computers create images from the radiation and add “false-color” to the wavelengths that we can not normally see. We can learn to identify specific features by the colors of a satellite image.• Grass, trees, crops-red• Water-black or blue• Cities-bluish gray
• GPS (Global Positioning System) is a system of satellites that can be used to make maps.• 3 or 4 satellites are needed to pinpoint the longitude, latitude, and elevation of a location.
• Never cross each other• Connect with themselves• Get closer together as land gets steeper• Get further apart as land gets flatter
•Contour interval- Acontour interval is thedifference in elevationbetween two contourlines that are side byside.•The contour interval isalways the same for thewhole map.•What is the contourinterval for this map?•25 meters.
• An index contour—every 5th contour line— is darker and heavier than the others and is labeled with the elevation in a nice round number.
• To read a topographic map, you must familiarize yourself with the map’s scale, symbols, colors and interpret the map’s contour lines.
• 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
• 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.• Easily visible closed loops indicated a hill top.• Dashed lines indicate a depression (a “hole” in the ground), such as a caldera (collapsed volcano) Steep Slope Gentle Slope
• V-shaped contour lines pointing uphill (to a higher elevation) are valleys.• A stream in a valley flows toward the open end of the V.
Review Questions• How are contour lines drawn on maps? – Connect points of equal elevation, never intersect, form loops although not always visible.• How does a contour map show whether a slope is gentle or steep? – Steep- lines close together – Gentle- lines far apart Valley• V-shaped lines pointing uphill indicate a ___________.• How do you know which way the water is flowing in a valley stream? – Water flows toward open end of the V.