4 “Hemi” is the Greek word for half Hemisphere means half of a sphereThe imaginary line that divides the world into the northern and southern hemisphere is called the Equator.The imaginary line that divides the world into eastern and western hemisphere is called the Prime Meridian.
5 To locate places north or south of the Equator, geographers use lines of latitude.
7 What is the lowest latitude and the highest latitude? 0 degrees = equator90 degrees = poles (but what poles)
8 It is necessary to add N or S, so that it’s clear whether you are north or south of the equator
9 Some latitude lines have special names Some latitude lines have special names. They divide the earth into regions according to the amount of direct sunlight they receive.Arctic CircleTropic of CancerTropic of CapricornAntarctic Circle
10 Each degree north or south of the equator represents approximately 69 miles
11 Let’s try a few locations If I’m at 10 degrees North, how many miles am I from the equator and in which direction?If I’m at 45 degrees North, where am I?The problem with LATITUDE alone is that I can tell how far from the equator I am, but I can’t tell where I am on that latitude. I could be at 45 degrees north and be in the Atlantic, Pacific, Europe, Asia or the United States.In order to pinpoint a location you need…..
12 To locate places east or west of the Prime Meridian, lines of longitude are used. The Prime Meridian is at 0 degrees longitude.Lines of longitude begin and end at the North and South Poles
14 DEGREES OF LONGITUDEThe Earth was divided up by 360 evenly spaced lines running from pole to pole. These are were called DEGREES OF LONGITUDE.If I start at ZERO and go one degree EAST, I am at ONE DEGREE EAST LONGITUDE. If I go 90 degrees to the west, or one fourth of the way around the world, I am at NINETY DEGREES WEST LONGITUDESo, now, to identify my location, I simply have to give a longitude and a latitude. If I am 20 degrees north of the equator and 20 degrees east of the Prime Meridian, I describe myself at 20N, 20E.
15 Latitude and Longitude together will give you the absolute location of a place
16 Some interesting things: If I go halfway around the world from the prime meridian, I get to a line identified as 180 degrees of longitude. It is BOTH 180 EAST AND 180 WEST. The highest line of longitude, therefore, is 180.The highest line of latitude is 90.This line of 180 degrees is also known as the International Date Line: it marks a time zone change, but it also marks a date change
18 World Time ZonesPrior to the late 19th century, time keeping was done locally. Each town would set their clocks to noon when the sun reached its zenith each day. A clockmaker or town clock would be the "official" time and the citizens would set their pocket watches and clocks to the time of the town. Travel between cities meant having to change one's watch upon arrival.Once railroads began to operate and move people rapidly across great distances, time became much more critical. In the early years of railroads, the schedules were very confusing because each stop was based on a different local time.
19 In 1878, Canadian Sir Sanford Fleming proposed the system of worldwide time zones that we use today. He recommended that the world be divided into twenty-four time zones, each spaced 15 degrees of longitude apart. Since the earth rotates once every 24 hours and there are 360 degrees of longitude, each hour the earth rotates one-twenty-fourth of a circle or 15° of longitude.United States railroad companies began utilizing Fleming's standard time zones in In 1884 an International Prime Meridian Conference was held in Washington D.C. to standardize time and select the Prime Meridian. The conference selected the longitude of Greenwich, England as zero degrees longitude and established the 24 time zones based on the Prime Meridian.