• Save
Upcoming SlideShare
×

Like this presentation? Why not share!

# Latitude and longitude

## on Feb 10, 2014

• 936 views

maps

maps

### Views

Total Views
936
Views on SlideShare
922
Embed Views
14

Likes
0
0
0

### 3 Embeds14

 http://yvonnebrand.blogspot.com.es 7 http://northwoodcollege.fireflycloud.net 6 http://yvonnebrand.blogspot.mx 1

### Categories

Uploaded via as Microsoft PowerPoint

### Report content

• Comment goes here.
Are you sure you want to
Your message goes here
• You may want to discuss minutes and seconds. <br /> Degrees of latitude and longitude can be divided into sixtieths, or minutes (&apos;). Any location on Earth can be described as lying at a certain number of degrees and minutes of latitude either north or south of the equator and at a certain number of degrees and minutes of longitude either east or west of the prime meridian. For example, the United States Capitol in Washington D.C. is at 38 degrees 53 minutes north latitude (38° 53&apos; N.) and 77 degrees 0 minutes west longitude (077° 00&apos; W.). Minutes of latitude and longitude can be divided into sixtieths, or seconds ("), when more precise information on the location of a place is needed, for example, by navigators, surveyors, pilots, or map makers. <br />
• You may want to discuss how longitude came to be calculated. <br /> The invention of clocks during the Renaissance was the first step toward the reliable calculation of longitude. The clocks of that era, however, were too inaccurate for use in navigation. In 1714 the British Board of Longitude offered a large cash prize to anyone who could build a clock that would meet certain standards of accuracy throughout long ocean voyages. By 1735 John Harrison, a British clockmaker, had submitted the first of several clocks, the last of which won the prize for him. They were called chronometers. In 1766 Pierre Le Roy, a Frenchman, built a chronometer more accurate than Harrison&apos;s. From that time on, sailors have been able to determine longitude accurately by comparing local time with Greenwich mean time (GMT). Shipboard chronometers are set to show GMT. Because of the speed and direction of the Earth&apos;s rotation, local time at a given place will be one hour behind GMT for every 15 degrees west of the prime meridian and one hour ahead of GMT for every 15 degrees east of the prime meridian. For example, if a ship&apos;s chronometer reads 0300 (3:00 AM) and the ship&apos;s local time is 0800 (8:00 AM), the ship is 75 degrees east of Greenwich, or at 75° E. Special radio time signals allow navigators to check the accuracy of their chronometers. <br />
• Over the years, the position of the International Date Line has changed several times. Until 1845, the Philippines were on the eastern side of it (the same side as the United States). It was on the eastern side of the line because it was a Spanish colony and most Europeans arrived there via the Spanish colonies in South America. Indonesia, almost directly to the South of the Philippines, was a Dutch colony and most European arrivals came via the Cape of Good Hope. Thus Indonesia was to the west of the International Date Line. After the independence of the South American countries, most people travelling to the Philippines also came by way of the Cape of Good Hope, so it was decided to change from the east of the line to the west of the line. Alaska, originally claimed by Russia, was to the west of the International Date Line because most travellers arrived there by way of Siberia. When the United States bought Alaska in 1867 the line was moved to the west of it. The most recent change in the line was in 1995 when Kiribati moved a large segment of it to the east, so that the entire nation would be on the same side of the International Date Line. <br />
• Answers appear on mouse click. <br />

## Latitude and longitudePresentation Transcript

• Latitude and Longitude These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable. For more detailed instructions, see the Getting Started presentation. 1 of 17 © Boardworks Ltd 2005
• Learning objectives How can we locate places on a globe? What are lines of latitude? Why is the Prime Meridian in Greenwich? 2 of 17 © Boardworks Ltd 2005
• Latitude and longitude 1 A system of lines is used to find the location of any place on the surface of the Earth. Lines of latitude run in an east-west direction. Lines of longitude run in a north-south direction. 3 of 17 © Boardworks Ltd 2005
• Learning objectives How can we locate places on a globe? What are lines of latitude? Why is the Prime Meridian in Greenwich? 4 of 17 © Boardworks Ltd 2005
• Latitude Latitude (shown as a horizontal line) is measured in degrees north or degrees south of the equator, which is the line around the exact middle of the earth. Lines of latitude are often referred to as parallels. Arctic Circle (66° 30'' N) Tropic of Cancer (23° 30'' N) Tropic of Capricorn (23° 30'' S) Antarctic Circle (66° 30'' S) 5 of 17 © Boardworks Ltd 2005
• Latitude There are 89 such equally spaced lines of latitude to the north of the equator and 89 to the south of the equator. Where the 90th east-west lines would be are two points – the North and South poles. Each east-west line is a circle. The further it is from the equator the shorter its length. The 60th east-west line, for example, is only half as long as the equator! 6 of 17 © Boardworks Ltd 2005
• Latitude North Pole Equator South Pole 7 of 17 © Boardworks Ltd 2005
• Lines of latitude 8 of 17 © Boardworks Ltd 2005
• Learning objectives How can we locate places on a globe? What are lines of latitude? Why is the Prime Meridian in Greenwich? 9 of 17 © Boardworks Ltd 2005
• Longitude Longitude (shown as a vertical line) is measured in degrees east or west of something called the Prime Meridian. This is the line going from the North Pole to the South Pole and running through the middle of the Greenwich Observatory in London. Lines of longitude are often referred to as meridians. Prime Meridian 10 of 17 © Boardworks Ltd 2005
• Why is the Prime Meridian in Greenwich? Britain was a world leader in exploration and map making. Therefore, navigators of other nations often used British maps. As a result, in 1884 the meridian of Greenwich was adopted throughout most of the world as the Prime Meridian. 11 of 17 © Boardworks Ltd 2005
• Why is the Prime Meridian in Greenwich? There was still another reason for the selection of the Greenwich Meridian as 0o longitude. Travellers must change time by an entire day when they cross the 180th meridian. If this meridian crossed a large country, timekeeping would be difficult. But with the Greenwich Meridian set at zero, the 180th meridian is near the middle of the Pacific Ocean. It crosses only a small land area in northeastern Asia and divides some island groups in the Pacific. 12 of 17 © Boardworks Ltd 2005
• International Date Line To avoid differing dates in these Pacific islands, the nations of the world established a special line across which dates change. It swerves from the 180th meridian whenever convenient. This line is called the International Date Line. 13 of 17 © Boardworks Ltd 2005
• Latitude and longitude 14 of 17 © Boardworks Ltd 2005
• Latitude and longitude N These are lines of latitude always write these first a These are lines of longitude The latitude of ‘a’ is 20ºS… ‘a’ is 20º south of the Equator. The longitude of ‘a’ is 20ºW… ‘a’ is 20º west of the Greenwich Meridian. Therefore we write the latitude and longitude of ‘a’ as 20ºS 20ºW. 15 of 17 © Boardworks Ltd 2005
• Latitude and longitude Match the places with the correct latitude and longitude. 16 of 17 © Boardworks Ltd 2005
• Latitude and longitude b c e a f d g Write down the latitudes and longitudes of these places. 17 of 17 © Boardworks Ltd 2005