1.3 – Representing Earth’s Surface

Do Now Why are there so many types of maps?

Do Now Why are there so many types of maps? Because there are different maps for different purposes.

Key Words Equator Prime Meridian Representation Parallel Distorted/Distortion

Vocab Words Latitude Longitude Topographic Map Contour Line Contour Interval

Determining Location Today we use maps and computer programs to help us plan our routes. We use maps not just for travel, but for determining where something is located. Maps in the past were mostly on paper, but today we have endless technology that provides us with more details than before.

Global Grid The distance around Earth is measured in degrees. Scientists use two special Earth measurements to describe location. Latitude The distance north or south of the equator. The lines are parallel to the equator. They run east to west. (Measurements given in North or South). Equator divides the Earth into a northern and southern hemisphere. Longitude The distance east or west of the Prime Meridian. The lines are parallel to the Prime Meridian. They run north and south. (Measurements given in East or West) Prime Meridian divides the Earth into a eastern and western hemisphere.

Global Grid Latitude Longitude

Maps and Mapping A map is a flat representation of Earth’s surface. But the Earth is round. So not all of Earth’s features can be accurately represented on a flat surface. No matter what kind of map is made, some portion of the surface will always look either too small, too big, or out of place. The best projection is always determined by its intended use. Mapmakers have found ways to limit the distortion of shape, size, distance, and direction. The Mercator Projection The Robinson Projection The Conic Projection The Gnomonic Projection Topographic Maps Advanced Maps

The Mercator Projection In 1569, a mapmaker named Gerardus Mercator created a map to help sailors navigate around Earth. The lines of longitude are parallel, making the grid rectangular. The map was useful because, although the sizes and distances were distorted, it showed directions accurately. More than 400 years later, many seagoing navigators still use the Mercator Projection Map.

The Robinson Projection These maps show the most distances, sizes and shapes accurately. Areas that are distorted are usually at the edges of the maps. These are mainly used in classrooms to portray what the world looks like without needing a globe.

The Conic Projection Made by wrapping a cone of paper around a globe at a particular line of latitude. Various points are projected onto the paper. Areas that are distorted are usually at the edges of the maps. These are mainly used in classrooms to portray what the world looks like without needing a globe. There is almost no distortion along the line of latitude that’s in contact with the cone, but there can be much distortion in areas away from this latitude. Because accuracy is great over a small area, these maps are used to make road and weather maps.

The Gnomonic Projection Made by placing a piece of paper on a globe so that it touches a single point on the globe’s surface. Various points and lines are then projected onto the paper. Distances and directions are distorted on these maps, they are useful to sailors and navigators because they show with great accuracy the shortest distance between two points.

Topographic Maps A topographic map, represents Earth’s three-dimensional surface in two dimensions. Differ from other maps that have been discussed because topographic maps show elevation of Earth’s surface by means of contour lines. Also show the presence of bodies of water, roads, and government and public buildings, political buildings, and place names. Important for geologists, hikers, campers and anyone else interested in the three- dimensional lay of the land.

Topographic Maps Contour Lines – they tell the difference between changes in elevations. Lines that are closer together means that it is steep Lines that are further apart means that it is a gentle slope Contour Interval – tells you the difference in elevation between the adjacent lines Scale – helps you understand how big the mountain/hill actually is by measuring everything down to an accurate scale. Geologic Maps – Topographic map that has shaded areas. Different shades are different types of rock formations.

Advanced Technology Maps that are more accurate than ever before. We can use technology to precisely analyze Earth’s physical properties. Using satellites and computers to send and gather data. Usually in the form of pictures. Process is called remote sensing. We can also use “real-time” satellite information such as GPS (Global Positioning Systems) to get directions and more accurate data because it is close to real-time.

Group Activity Fill out this chart: Map Type Advantages Disadvantages Mercator Projection Robinson Projection Conic Projection Gnomic Projection