Latitude and Longitude The 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.
a) Latitude (Parallels) b) Longitude (Meridians) The Geographic Grid
Latitude lines are 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. There is a slight variation because the earth is not round, but more ellipsoid.
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 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 1 st , LONGITUDE 2 nd
N or S°, E or W°
For Example- Yucaipa, 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.
Using your atlas
An atlas is a collection of maps compiled into an easy-to-use format
It usually has an accompanying index, which is an alphabetical listing of place names and their pronunciations
Atlases may be general in nature and cover the entire globe, or they may be specific to geographical locations, topics or time periods
Specialized atlases exist in a wide variety of topics
Most libraries have atlases in their reference sections.
Goode’s World Atlas
Contains information about:
The edition of the Atlas you are using
Basic Earth properties
Information on longitude and latitude, important grid lines, and more
Information about the different types of maps included in the atlas
This section is very important!
Contains information about the symbols used on the maps
For example, shows the different sized dots that are used to represent cities and what the population is for each sized dot
Also shows the symbols used to depict landforms
Tables and Indexes
Goode’s World Atlas
World Maps Section
This section contains many world maps including:
Political, physical, landforms, volcanoes, ocean floor, climates, vegetation, soil, population density, gross domestic product, literacy, languages, minerals, nuclear power, military power, telecommunications, and more.
Goode’s World Atlas
Regional Maps Section
This is separated into regions with many different maps of each region.
The regions in this atlas are:
Australia, Oceania, and Antarctica
Oceans and Arctic Region
Goode’s World Atlas
Tables and Indexes Section
This section contains an alphabetical list of all of the places in the atlas, which includes a pronunciation guide, page number where the place can be found in the atlas, and the latitude and longitude coordinates.
It also contains:
A glossary of foreign geographic terms
General Information about:
Land area of islands, area of lakes and oceans, heights of mountains, length of rivers, population for large cities
World Political Information
World Demographic Information
World Agriculture Information
World Economic Tables
Early agricultural societies found that local noon could be determined by observing the changing length of the shadow cast by a stick placed perpendicular to the ground. Local noon is the time at which the shadow is the shortest length cast. Romans used this principle to design their sundials and called their noon position of the Sun the "meridian" ( meridiem - the Sun's highest point of the day).
It was difficult to compare time as one traveled to different localities as each city adjusted its clocks to their own local noon.
Because the Earth rotates toward the east, towns to the east experienced solar noon earlier while those to the west later.
As cross-country travel and communication became faster and more efficient, a standardized system of global time was required.
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.
International Date Line Ferdinand Magellan and crew in 1519 set out on their westward journey from Spain to circumnavigate the Earth. Upon their return three years later, they discovered that their meticulously kept logs were off by one day. This was one of the first recorded experience with changing global time. This earlier experience would ultimately lead to the establishment of the international date line. The International Date Line lies directly opposite of the prime meridian and having a longitude of 180°. Crossing the line when traveling east one turns their calendar back a full day. Traveling west one moves their calendar forward one day. http://www.danstopicals.com/dateline.htm
Daylight Saving Time
Many countries observe daylight saving time - the practice of setting clocks forward one hour in the spring and back one hour in the fall.
First proposed by Benjamin Franklin, the notion of extending daylight one hour into the evening didn't catch hold until World War One as a means of energy savings.
Some countries, territories, and states in the U.S. do not observe daylight saving time.
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 This map does NOT include Alaskan or Hawaiian time zones. Atlantic Standard Time and Newfoundland are NOT in the US, they are Canadian.