Earth Mapping

Maps

A map is a model of Earth.  You can make a flat representation of the Earth on paper, if you want to model the entire planet you can make a globe.

Map Views

• Map view is when maps are drawn as if you were looking down on an area above Earth's surface, it can also be called plan view

• A profile view is a drawing that shows an object from the side

Map Legends and Scales

• Map legends are a key that lists all the symbols used on a map and explains what they mean

• Map scales show the relationship between a distance on the map and the distance in reality - it can be written verbally, as a ratio or as a graph

Longitude and Latitude

• Longitude is the distance in degrees East or West of the prime meridian

• The Prime Meridian at 0° and the 180° meridian divide Earth into east and west

• Latitude is the distance in degrees North and South of the equator, these lines are all parallel to each other 

• The Equator is at 0° and is the largest circle

• We plot longitude and latitude using degrees, minutes and seconds

Time Zones

• A time zone is the area on Earth's surface between two meridians where people use the same time, the reference point for time zones is the prime meridian

• Earth is divided into 24 time zones, the standard width is 15° longitude, however this can change due to political boundaries

• The International Date Line is the 180° line of longitude east or west of the prime meridian, it doesn't follow the 180° meridian exactly as some islands would be split by time

Map Projections

• Cylindrical Projections show shapes near the equator well, but shapes near the poles are enlarged

• Conical Projections has very little distortion near the line of latitude where the cone touches the globe but it's distorted elsewhere

• All types of projections distort the shapes, in maps where continents are accurately represented, it's only because areas such as oceans are cut away or distorted

Types of Maps - General Use

• Physical maps: use lines, shading and color to indicate features like rivers etc.

• Relief maps: use shading and shadows to identify mountains and flat areas

• Political maps: show boundaries between countries, states etc.

• Road maps: can show interstates or a range of roads

Types of Maps - Topographic Maps

• A topographic map shows he detailed shapes of Earth's surface

• The height above sea level at any point on Earth's surface is elevation, the difference between the highest and lowest point of elevation in an area is called relief

Contour Lines

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Contour lines are imaginary lines that connect points of equal elevation.

The contour interval is the elevation difference between contours next to each other. The slope is a measure of how steep the land is. Contours spaced far apart show a gradual or flat slope, close together they indicate a steep slope.

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Types of Maps - Geologic Maps

• Geologic maps show the surface of geology of the mapped area - this includes rock types, ages and locations of faults

• Different colors and symbols represent different rock formations

• Geologic cross sections are vertical slices through the surface to show the layers of rocks below the surface of the Earth

Making Maps Today

Making Maps Today

• Global Positioning System - GPS is a group of satellites used for navigation

• Geographic Information System - GIS combin data collected from many sources, including satellites, scanners and aerial photos

• Remote Sensing - the process of collecting information about areas without coming into contact with it, such as through photographs

• Today satellites orbit Earth repeatedly and can help us study changes in the area, particularly after natural disasters