Map Skills Geography 8th Mrs. Reed

What is an atlas? A book of maps The term atlas is taken from Greek mythology for the defeated titan that was condemned by Zeus to support the world on his shoulders. Hence, historians/geographers term a book of maps….as an atlas. Lower case “a”.

Atlas-Greek Mythology

Review your text atlas Pages A2-A22 What kinds of maps are located in your atlas?

Maps-Found The two types of maps found in your atlas are political & physical of the Earth.

On the physical map, how is elevation represented? What colors represent mountains on a physical map? Why is this map called a physical map? What features are represented on a physical map? Name a few, and how they are represented?

What is represented on a political map? Why is it called a political map? On some political maps, broken lines with one dot between them often show boundaries between states and provinces. How does your textbook atlas represent state boundaries for the United States? Check page A8 & A9.

Political maps continued How are national boundaries represented in your text atlas? How are national capitals represented? How are general cities represented?

Mapping the Earth

Key terms: Leave space to define Globe grid Latitude equator Parallels degrees Longitude prime meridian hemispheres

Globe A globe is a scale model of Earth. It is useful for looking at the entire Earth or at large areas of the Earth’s surface.

Grid The patterns of lines that circle the globe in east-west and north-south directions is called a grid. The intersection of these imaginary lines helps us find places on Earth.

Latitude The lines that run east-west and are measured from the equator north and south are the latitudes.

Equator The equator serves as an imaginary line that circles the globe halfway between the North and South Poles.

Parallels Lines of latitude are called parallels because they are parallel to the equator.

Degrees Parallels measure distance from the equator in degrees.

Longitude The lines that run north to south and are measured east to west are longitude. These imaginary lines pass through the globe.

Prime meridian Lines of longitude measure the distance east and west of the prime meridian. The prime meridian is an imaginary line that runs through Greenwich, England.

Important parallels Two important parallels in between the poles are the Tropic of Cancer at 23 ½ degrees north latitude; and the Tropic of Capricorn at 23 ½ degrees south.

What is a hemisphere? As already noted, to locate places on the Earth, geographers use imaginary lines that crisscross the globe. One of these lines, the Equator, circles the middle of the earth like a belt. It divides the earth into “half spheres”, or hemispheres.

Everything north of the Equator is in the Northern Hemisphere Everything north of the Equator is in the Northern Hemisphere. Everything south of the Equator is in the Southern Hemisphere.

Southern Hemisphere

Northern Hemisphere

Hemispheres-cont. Another imaginary line runs from north to south and helps divide the earth into half spheres in the other direction. This line is called the Prime Meridian. East of Prime Meridian is the Eastern hemisphere; west of the Prime Meridian is the Western Hemisphere.

One moves 180 degrees either east or west from the Prime Meridian to encounter the Eastern or Western Hemispheres.

In which hemispheres is North America located? Review your text S2 & S3.

More Map Features

Map Projections Globes are the best, most accurate way to show the round Earth. Using a globe has its difficulties, though. A globe is too large and awkward to carry around. For these reasons, geographers use maps instead.

Map Projection A map is made by taking data from a round globe and placing it on a flat surface. It is important to remember that the earth’s features, which are shown accurately on a globe, become distorted when the curves of a globe becomes straight lines on a flat map.

Map Projection Imagine taking the whole peel from an orange and trying to flatten it on a table. You would either have to cut it or stretch parts of it. Map makers face a similar problem in showing the surface of the round earth on a flat map. To fill in the gaps, mapmakers stretch parts of the earth.

They choose either the correct shape or the correct size They choose either the correct shape or the correct size. It is impossible to show both. As a result, mapmakers have developed different projections, or ways of showing the earth on a flat piece of paper. Each projection has its strengths and weaknesses.

Mercator Projections Mercator map projection shows land shapes fairly accurately but not size or distance. Alaska and Greenland appear much larger on a Mercator projection than a globe due to distance from the equator.

Mercator Projection A Mercator Projection shows true direction which makes it useful for sea travel.

Robinson Projection A map using the Robinson projection shows size and shape with less distortion than does a Mercator map.

Robinson Projection Land on the western and eastern sides of the Robinson map appear as they do on a globe. The areas most distorted on this map are near the poles. Atlases use the Robinson projection.

Goode Projection A map with a Goode Projection shows continents close to their true shapes and size. Distance, especially in the oceans, are less accurate.

Goode Projection The Goode projection would be helpful if one wanted to compare land area data about continents.

It shows shapes accurately but is very inaccurate for size. Projection Quiz 1.Tell one inaccuracy in the Mercator Projection. It shows shapes accurately but is very inaccurate for size.

Areas near the equator. Projection Quiz What areas of the world are portrayed most accurately on the Mercator map? Areas near the equator.

Projection Quiz Which map do you think is probably the least accurate in measuring distances across water? Explain your reasoning. Goode’s projection is able to be more accurate for both size and shape but it is hard to tell distances across water.

Projection Quiz Why do you think most geographers prefer using Robinson Projection maps? Minor distortions of size at high latitudes are balanced by realistic shapes at the middle and low latitudes.

Graphs, Charts, & Tables Graphs and charts are a visual way to present information.

Bar Graphs Bar graph n. A graph consisting of vertical bars or horizontal with lengths proportional to the amounts of the data being compared. Similar to a histogram One axis will tell you what is being measured. The other axis tells what unit of measurement are being used. Bar graphs are especially useful for comparing quantities.

Horizontal Bar Graph On a horizontal bar graph the vertical axis shows data that is being compared and the horizontal axis shows numerical data.

Vertical Bar Graph On a vertical bar graph the vertical axis shows numerical data and the horizontal axis shows data that is being compared.

Line Graphs In a line graph, the vertical axis shows the units of measurement; horizontal axis shows data that is being compared.

Multiple Line Graphs Multiple line graphs show trends by making multiple comparison.

Charts A pie chart or graph shows how a whole is divided into parts. Each “slice” represents a part of the whole “pie”.

Halloween Costumes

Diagrams Diagrams are drawings that show steps in a process, point out the parts of an object, or explain how something works.

Cow Diagram

Venn Diagram

Pictograph Pictographs use rows of small pictures or symbols, with each picture or symbol representing an amount.

World Time Zones P. S14 Since our sun is only directly over one area at a time, the world is divided into time zones. Since there are 360 degrees in a circle, we know that the planet turns 15 degrees of longitude each hour. 360 divided by 24(hrs)=15 degrees.

World Time Zones The planet turns in a west-to-east direction. If a place on the Earth has the sun directly overhead at this moment (noon), then a place 15 degrees to the west will have the sun directly overhead one hour from now. Thus, an hour later the planet has rotated 15 degrees.

World Time Zones

Map Skills The End