LATITUDE AND LONGITUDEREVISITED

DAY 4

Latitude lines are imaginary lines on the earth's surface that run east and west. They tell you your distance in degrees north or south of the Equator. Think of latitude like the rungs of a ladder (ladder sounds like latitude) that also run east and west.

Longitude lines are imaginary lines on the earth's surface that run from the North Pole to the South Pole, encircling the globe. They and tell you your distance in degrees east or west of the Prime Meridian. When you think of longitude, think of long, tall telephone poles (because longitude lines run from pole to pole).

In the field of mathematics, circles are measured in degrees. There are 360° in a circle. Since the earth is basically circular, it was decided to measure latitude and longitude in degrees also.

Why Degrees?

The Equator is equally distanced between the north and south poles.

It is the longest of all latitude lines. (Look at this line of latitude compared to others on a globe.)

All other latitude lines are measured in degrees north or south of the Equator.

Altogether there are 90 degrees of latitude to the north and 90 degrees of latitude to the south of the Equator.

EQUATOR

The Prime Meridian lies at 0° longitude. All other longitude lines are measured in degrees east or west of the Prime Meridian. There are a maximum of 180 degrees on longitude to the east or the west of the Prime Meridian.

For more accuracy in location, degrees can be divided into smaller parts. One degree can be divided into 60 minutes (') and one minute can be divided into 60 seconds (").

PRIME MERIDIAN

•If someone asked you the location of McDonalds, you may say: "It is at the intersection (corner) of Airline Drive and Viking Drive." •Latitude and longitude are like imaginary streets on the earth. The place where the two lines intersect (cross) is the absolute location.•It is customary to list the latitude of a place first and the longitude second. •For example, you would say "35° N, 77° W". This eliminates the need to say the words latitude and longitude. •Make sure that you give a direction with the number. If you simply say "66° latitude", there are two of them - one is north and one is south.

Using Latitude and Longitude to Pinpoint a Location

To find a latitude line such as 60° N, you must do three things:

1. Begin at your starting line (the Equator).

2. Determine which direction you must go (north or south).

3. Determine the distance in degrees you must go (ex. 60°). This will give the location of one of your two map location points.

Finding Latitude

To find a longitude line, you must also doThre e things:

Go to your starting line (the Prime Meridian).

1. Determine which direction you must go (east or west).

2. Determine the distance in degrees you must go (ex. 40°). This will give the location of the second of your two map location points.

Finding Longitude

To find a longitude line such as 60° W, you must do three things:

1. Begin at your starting line (the Prime Meridian).

2. Determine which direction you must go (east or west).

3. Determine the distance in degrees you must go (ex. 60°). This will give the location of the second of your two map location points.

If you find the intersection of these two lines, you have found the exact (absolute) location of a particular place on the earth's surface (shown by the red "X" on the map below).

Important: The equator is neither North nor South of the starting line, so it is simply 0° latitude (no direction needed). The prime meridian would be 0° longitude (no direction needed).

In real life, there are several instances where you would need to know how to find latitude and longitude. For example, when weather forecasters are tracking hurricanes, they note the absolute location on a periodic basis to see the path of the storm and try to predict the future path based partially on these findings.

Another example would be in the military. Suppose you were at war and you wanted to blow up an ammunition factory, but not the hospital nearby. Using minutes and seconds of latitude and longitude, you can launch a missile from hundreds of miles away and strike only that particular building.

In an emergency situation, like a plane crash or a ship sinking, you can relay your coordinates of latitude and longitude to assist rescue teams when time may be very important. If you are in the middle of an ocean, there are no landmarks to use, so you had better know your latitude and longitude.

In the event of a 911 emergency, the address associated with phone number from which the call is

made is not necessarily the location to which emergency responders will be sent. The Federal Communications Commission requires that all

network operators provide the latitude and longitude of the place from which the call was

placed.

Let’s see what you have learned about Latitude and Longitude.

In which hemispheres would each of these absolute locations be found (choose the correct letter)?

1. 41°N, 21°E2. 37°N, 76°W3. 72°S, 141°W4. 7°S, 23°W5. 15°N, 29°E6. 34°S, 151°E

A B

C D

1. B 2. A3. C4. C5. B6. D

The United States is which direction from the Prime

Meridian?

A) WestB) South C) East D) North

Which letter marks the spot where the Prime Meridian and the Tropic of Capricorn intersect (cross)? The answer is C

In which hemispheres do the Tropic of Cancer and the Equator intersect?

A) Northern and WesternB) Southern and EasternC) Northern and Eastern D) None of the above

If you said D, then great job! These are both lines of latitude, which means they are parallel, and as you know parallel lines NEVER intersect!!!