1. LINES OF LATITUDE AND LONGITUDE
The location of any point on the earth’s surface can be pinpointed by using lines of latitude and longitude. They are measured in degrees.
Lines of latitude runs from east to west around the world and extends from 0 to 90 degrees North and South of the equator.
Lines of longitude runs from north to south around the world and extends east or west of the Prime Meridian. An important line of longitude is the Prime Meridian which is at 0 degrees. It is also called the Greenwich Meridian because it passes through Greenwich in London.

3. There are five important lines of latitude :
The equator which divides the northern and southern hemispheres.
The Tropic of Cancer which is at 23 1/3 degrees North. Almost the whole Caribbean lies between the Tropic of Cancer and the equator. So it is said that we are located in the Tropics. In the Tropics the climate is generally warm and hot.
The Tropic of Capricorn which is at 23 1/3 degrees South .
The Artic Circle which is at 66 1/3 degrees North . The lands north of the Artic Circle are called the Artic. The climate is cold . Mid winter is in December and mid summer is in June.
The Antartic Circle which is at 66 1/3 degrees South. In the Southern Hemisphere mid winter is in June and mid summer is in December.

4. MOVEMENTS OF THE EARTH
The earth is not flat but is spherical in shape. This spherical shape is called a geoid.
The earth is responsible for two movements:
It rotate
It revolves
The earth rotates once in 24 hours and this results in :
Day and Night
The deflection of winds and ocean currents
The daily rising and falling of tides.
The earth takes 365 ¼ days to revolve once around the sun. Every fourth year is given 366 days and this is called a leap year. All others have 365 days.
The earth axis always points in the same direction in the sky i.e. to the Polar star. The revolution of the earth and the inclination of its axis results in :
Changes in the altitude of the midday sun at different times of the year.
Varying lengths of day and night at different times of the year.
The four seasons.

5. ROTATION OF THE EARTH
Rotation is the movement of the earth around an imaginary axis (north and south pole).

6. Revolution is the movement of the earth in an elliptical orbit around the sun whose average distance is 93 million miles away. The time to travel 1 orbit = 1 year. During this time there are rotations of the earth

7. DAY & NIGHT
The earth rotates from west to east causing day and night. It spins on its axis once every 24 hours.
Places to the east see the sun first while other places away from the sun are in darkness.
When the sun is directly or vertically overhead at the equator on March 21st and September 23rd , all places over the world have 12 hours of daylight and 12 hours of night.
The earth axis is titled at 231/2 degrees as it follows an orbital path around the sun. Its spins on its axis from west to east , the sun which is in a stationary position appears to rise in the east and set in the west.
When the sun is located at its furthest point in the northern hemisphere June21, the southern hemisphere has its longest night.
The artic circle 661/3 N receives 24 hours of daylight during the summer solstice and the Antarctic circle 661/3 S receives 24 hours of darkness.

8. SOLSTICE
Solstice refers to the point on the plane of the ecliptic when the sun reaches its maximum inclination from the equator and then changes direction in its northwards and southwards movement.
It is the position of the overhead sun when it reaches its maximum declination from the equator from the equator that is 23 1/3 N or 23 1/3 S.
On March 21ST the sun is overhead at the equator.
On June 21 at 23 1/3 N it is at the Tropic of Cancer where its midday rays are felt directly overhead.
The summer solstice is on June 21st in the northern hemisphere .
The winter solstice is on June 21st in the southern hemisphere.
On September 23rd the sun is overhead at the equator . The sun is overhead at the equator twice per year.
On December 21 the sun is overhead at the Tropic of Capricorn . The midday sun is directly overhead.
December 21st is the winter solstice in the northern hemisphere and summer solstice in the southern hemisphere.

9. Tilt of the Earth (Inclination of the Earth's Axis) The axis of the earth's rotation is inclined 66.5 degrees from the plain of the ecliptic or 23.5 degrees from an imaginary line vertical to it. The angle of inclination of the earth's axis is constant; this is known as the parallelism of the axis.

10. EQUINOXES
During an equinox places along the equator have equal days and nights.
There are two equinoxes :
When the sun is overhead at the equator on March 21st , there is the spring equinox.
When the sun is overhead at the equator on September 23 , there is the autumn equinox.
When the sun is directly overhead at noon at the equator the rays of the sun fall directly on the equatorial belt.
All places over the world would have equal day and equal night as the axis is titled neither towards or away from the sun.

11. EQUINOXES At the times of the two equinoxes, then the sun's noon rays are vertical at the equator, the circle of illumination cuts all parallels in half, so that days and nights are equal (12 hr) over the whole earth.