2 - using latitude & longitude to determine your position on Earth. Coordinate System- using latitude & longitude to determine your position on Earth.
3 Latitude Longitude line running east to west measures the distance in degrees North and South of the equator.measured by parallels, because all lines of latitude are parallel.largest value of latitude is 90°- Equator – 0°00’ N/S- North Pole – 90°00’ N- South Pole – 90°00’ S- Horseheads, NY – 42°10’Nline running north to southmeasures the distance in degrees East and Westof the prime meridian.All meridian lines meet at the poles and are further apart at the equator. They are not parallellargest value of longitude is 180°Prime Meridian – 0°00’ E/W Horseheads, NY – 76°51’ W
4 Latitude49oLatitude lines are also called PARALLELS because they run parallel to the equator.
5 LatitudeAt night in the Northern Hemisphere, latitude can be determined by measuring the altitude of Polaris (North Star)40o
6 To PolarisTo Polaris90°40°HorizonTo PolarisNorth Pole0°
7 Longitude Based on the Sun’s Apparent motion through the sky. How long does it take the Earth to rotate once on its axis?24 hoursHow many degrees does it rotate in this time?360oDegrees per hour = 360/24 = 15o/hour
8 LongitudeThe distance, in degrees, measured east or west of the Prime Meridian.Prime Meridian passes through Greenwich, England (Longitude 0o)
9 Measuring Longitude Greenwich Mean Time (GMT) Solar Time – (noon) what time it is in Greenwich, England0o line for longitudeSolar Time – (noon)when the sun reaches it highest altitude in the sky at your location.
10 Measuring LongitudeRemember – the Earth rotates at 15o/hr and that the Sun “appears” to move through the sky at the same rate.If you know what time it is in Greenwich when it is noon at your location you can calculate you longitude.
11 Measuring LongitudeIt was 2:00 pm in Greenwich (GMT) when it was noon at your location (12:00pm)Time Difference =?2 hours2 hours X 15o/hr= 30oYour longitude = 30oW Earth Rotates from W to E Note – If it is NOON your time and GMT = PM, you are WEST of the P.M.If it is NOON your time and GMT = AM, you are EAST of the P.M.