Map A model or representation of the Earths

• Map • A model or representation of the Earth’s surface • Reference point • Is a fixed point on the Earth’s surface from which direction and location can be described – Example: a landmark like the north or south pole (because the Earth is round) • Cardinal directions • North, south, east and west – More precise than left, right, and straight – True north: the geographic north pole – it never changes, unlike the magnetic north pole • Latitude • Imaginary lines drawn around the Earth parallel to the equator – Called parallels – The distance north or south from the equator measured in degrees • equator • A circle ½ between the poles that divides the Earth between Northern and Southern Hemispheres – 0° latitude

• Longitude • Imaginary lines that pass through the poles – Called meridians – The distance east or west from the prime meridian measured in degrees – Not parallel, touch at the pole and farthest apart at the equator • Prime Meridian • The meridian selected to be 0° longitude – – Greenwich, England Does not completely circle the globe 180° is the opposite side Eastern Hemisphere is between 0°-180° east of Prime Meridian – Western Hemisphere is between 0°-180° west of Prime Meridian • Using Latitude and Longitude • Find the intersecting points on the map – The points make a grid, connect north & south with east & west points

• Losing accuracy • Because the Earth is a sphere, accuracy is lost when information is transferred – Distortions in shape and distance • Mercator Projection • A map projection where the contents of the globe are transferred onto a cylinder of paper. – Latitude and longitude lines are straight & parallel – Widens the area near the poles • Conic Projection • A map projection made by transferring the contents of the globe onto a cone and unrolled – Touches each line of longitude, but only one line of latitude – Distortion occurs along the lines of latitude further away from the one touching the cone – Best for East/West landmasses

• Azimuthal Projection • A map projection made transferring the globe onto one plane – Only touches one point, usually a pole – Little distortion at that point – Distortion occurs from that point on • Modern Map Making • Aerial Photographs – give a bird’s-eye view • Remote sensing – gathering information without actually being there (satellites) • Information on Maps • The keys to what is on any given map – Title – telling you what type of map it is – Scale – Earth surface vs. map surface • • • Graphic scale – comparison ruler Verbal scale – describes the scale Representative fraction – ratio Compass rose – shows North Legend – shows symbols (key) Date – when the map was accurate