Presentation on theme: "Reading Maps Earth Science Mr. Bimber. Map Projections: You cant draw the round earth on flat paper, so all maps are distorted. Take a transparent globe."— Presentation transcript:
Reading Maps Earth Science Mr. Bimber
Map Projections: You cant draw the round earth on flat paper, so all maps are distorted. Take a transparent globe with a light shining out from the center. Trace the outlines of the land on a piece of paper held against the globe. Thats a map projection.
Cylindrical Projection A cylindrical projection: the map is traced on a cylinder. Latitude and Longitude lines are always right angles. –This is good for navigators and pilots. The areas near the poles are larger, and distorted. –Mercator maps are cylindrical
Azimuthal Projections Azimuthal Projections are traced on flat paper. Shape & direction are distorted near the edges. Examples: polar projection, gnomonic projection.
Conic Projections Conic projections are traced on paper rolled into a cone. They are distorted near the top and bottom, and latitude lines are curved. These have the least distortion for small area maps: almost all road and state maps are conic projections.
Map Scale A Maps Scale lets you measure and compare map distances to distances in the real world. The scale can be marked rulers, a ratio, or a fraction –(This map scale as a fraction would be 1/250,000.)
Map Scales Compared Small scale maps show more of the world, but less detail. … Large scale maps show less area, but more detail.
Map Scales check: Which map shows the most land area? Which map shows the most detail? Is the map on the left smaller or larger scale? Two places three inches apart on the left map are how far apart in the real world?
Latitude Latitude lines run east and west in circles all the way around the earth. They are measured in degrees north or south of the equator.
Longitude Go only half way around the earth. Lines run between north and south poles. Lines are east or west of the Prime Meridian.
Latitude and Longitude You can locate any place on earth by giving its Latitude north or south of the equator, and its Longitude east or west of the Prime Meridian.
Degrees, minutes, seconds To locate places more accurately, each degree can be divided into sixty arc minutes, and each minute into sixty arc seconds.