UNIT 1. PLANET EARTH

David Pardos Grao

4. THE GEOGRAPHIC

COORDINATES.

P a r a l l e l s a n d Meridians: grid of imaginary lines that help us to find a place.

Parallels

Imaginary circles in an East-West direction.

There are 90 parallels in the north and 90 parallels in the south

Important parallels

Equator (0º)

Artic Circle

Tropic of Cancer

Tropic of Capricorn

Antartic Cricle

Meridians

Imaginary semicircles running in a North-South from pole to

pole. There are 360 meridians. 180 meridians en each part (east

and west)

PRIME MERIDIAN: Greenwich Meridian

LATITUDE AND LONGITUDE: INDICATE THE GOEGRAPHIC COORDINATES OF A PLACE.

Latitude: is the distance from a parallel to the

equator.

North-South. Parallels show latitude. It is measured in

degrees (º), minutes (‘), and seconds (‘’).

Its values go from 0º at the equator to

90º.

LATITUDE AND LONGITUDE: INDICATE THE GOEGRAPHIC COORDINATES OF A PLACE.

Longitude: is the distance from a meridian to Greenwich meridian.

East-West Meridians show longitude.

It is measured in degrees (º), minutes (‘), and seconds (‘’).

Its values go from 0º at the Greenwich

to 180º.

HOW DO WE LOCATE A PLACE ON A MAP?

We always need the geographic coordinates (longitude and latitude)

•  Longitude is at the top and bottom of the map

•  Latitude is placed in the right and left of the map

HOW DO WE USE SCALE ON A MAP??

•  Map scale: it is a reduced representation of a real area. Scale indicates the difference between the size on a map and real world.

Types

Numeric scale is expressed as a fraction.

Numerator represents the distance on the map

Denominator represents its distance in real world

Units are in centimeters

Graphic scale

Bar looks like a small ruler

Numbers indicates the distance on the map and the equivalent in the real world

NUMERIC SCALE

1: 10.000

1= centimeters on the map

10.000= centimeters in the real world

GRAPHIC SCALE

HOW TO USE SCALE TO CALCULATE DISTANCES

INTERPRETE: SCALE 1:50.000 MEANS 1 CM

ON THE MAP IS EQUIVALENT TO 50.000

CM IN THE REAL WORLD

MEASURE THE

DISTANCE IN THE MAP

CALCULATE: YOU HAVE TO MULTIPLICATE THE DISTANCE MEASURED

BY THE DENOMINATOR

CHANGE CENTIMETRES

INTO KILOMETRES