Latitude and LongitudeThe latitude and longitude system was developed in the middle ages. Ptolemy also used a grid system in ancient Greece.

Latitude lines run horizontally and are also known as parallels.

Longitude lines, also known as meridians, run vertically.

LATITUDE LONGITUDE

Latitude

Latitude also known as parallels because they are parallel and are an equal distance apart from each other.

Each degree of latitude is approximately 69 miles apart. One way to remember latitude is to imagine it as the rungs of a ladder, “ladder-tude.” Degrees of latitude are numbered from 0 to 90, both north and south. 0° is the Equator, the imaginary line that divides the earth into northern and southern

hemispheres. 90° north is the North Pole and 90° south is the South Pole.

The Equator: 0° N/S

Longitude

Longitude lines are also known as meridians. They are about 69 miles apart at the equator, they converge at the

poles. 0° longitude is located at Greenwich, England. The degrees continue to 180° east and west until they meet at the

International Date Line in the Pacific Ocean.

Prime Meridian: 0° E/W• Greenwich, England: the site of the

British Royal Greenwich Observatory, was established as the site of the Prime Meridian by an international conference in 1884.

International Date Line 180° E/W

Longitude and Latitude

Degrees longitude and latitude are divided into minutes (') and seconds (").

– There are 60 minutes in each degree. Each minute is divided into 60 seconds.

– Seconds can be further divided into tenths, hundredths, or even thousandths.

For example, the U.S. Capitol is located at 38°53'23"N , 77°00'27"W

– Or 38°, 53 minutes, and 23 seconds north of the equator and 77 degrees, no minutes and 27 seconds west of the meridian passing through Greenwich, England).

How to write Latitude and Longitude

Coordinates of latitude and longitude are ALWAYS written as

LATITUDE 1st, LONGITUDE 2nd

N or S°, E or W°

For Example- Rancho Cucamonga, CA:34° N, 118° W

Directions MUST always be included in the coordinates

Using Latitude and Longitude

AAA is located at the corner of Haven Ave. and Foothill Bl.– Latitude and longitude are like imaginary streets on the earth.

1. Go to your starting line (the Equator).2. Determine which direction you must go (north or south).3. Determine the distance in degrees you must go.

*This will give you the location of one of your streets*

1. Go to 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.

*This will give the location of your second street.*– If you find the imaginary intersection of the two roads, then you have

found the exact location of a particular place.

 

Standard Time

• The globe is divided into 24 time zones in the Standard Time System.

• All inhabitants within a zone keep time according to a standard meridian that passes through their zone.

• Since standard meridians are usually 15° apart, the difference in time between adjacent zones is normally one hour.

– In some geographic regions the difference is only half an hour.

Standard Time• Given the Earth rotates once throughout a 24 hour period, 24

standard times zones were agreed upon at the 1884 International Prime Meridian Conference.

• The local solar time at Greenwich, England was designated the prime meridian. Each time zone extends 7.5° on either side of a central meridian.

• For years the global standard for reporting time was Greenwich mean time (GMT).

• GMT is now referred to as Universal Time Coordinated (UTC)  but the prime meridian is still the reference for standard time.

Standard Meridians

There are 24 standard meridians.

They are all 15° apart. The first standard meridian is

the Prime Meridian. Time does NOT change at the

standard meridians.– The standard meridian is the middle of the time zone.

– Time zones extend 7.5° on each side of the standard meridian.

US Time Zones

Global Time• Our planet requires 24

hours for a full rotation with respect to the sun, and our global time is oriented with some respect to the sun.

• 15° of longitude equates to one hour of time.

• Since Earth turns 360° in a 24-hour day, the rotation rate is: 360° ÷ 24 hours = 15°

per hour.

http://www.flickr.com/photos/telstar/433029904/

Time

• A solar day is defined by one sun circuit.

• Solar noon (at a particular location) is the time of the highest solar angle.

• The time is calculated by the position of the Sun at selected meridians (Standard Time).

Military TimeMilitary Time

• Military time is an unambiguous, concise method of expressing time used by the military, emergency services (law enforcement, firefighting, paramedics), hospitals, and other entities.

• The following sections provide a detailed description of the difference between regular and military time, how military time is written, and several time conversion examples.

Military TimeMilitary Time

• The main difference between regular and military time is how hours are expressed.

• Regular time uses numbers 1 to 12 to identify each of the 24 hours in a day.

• In military time, the hours are numbered from 00 to 23. Under this system, midnight is 00, 1 a.m. is 01, 1 p.m. is 13, and so on.

• Regular and military time express minutes and seconds in exactly the same way.

• When converting from regular to military time and vice versa, the minutes and seconds do not change.

• Regular time requires the use of a.m. and p.m. to clearly identify the time of day.

• Since military time uses a unique two-digit number to identify each of the 24 hours in a day, a.m. and p.m. are unnecessary.

Military TimeMilitary Time

Regular Time Military Time Regular Time Military Time

Midnight 0000 Noon 1200

1:00 a.m. 0100 1:00 p.m. 1300

2:00 a.m. 0200 2:00 p.m. 1400

3:00 a.m. 0300 3:00 p.m. 1500

4:00 a.m. 0400 4:00 p.m. 1600

5:00 a.m. 0500 5:00 p.m. 1700

6:00 a.m. 0600 6:00 p.m. 1800

7:00 a.m. 0700 7:00 p.m. 1900

8:00 a.m. 0800 8:00 p.m. 2000

9:00 a.m. 0900 9:00 p.m. 2100

10:00 a.m. 1000 10:00 p.m. 2200

11:00 a.m. 1100 11:00 p.m. 2300