Global Context

Chapter Three

Earth BasicsSurface Area = 510 million square km197 million square miles

70% Water30% Land

Freshwater covers about 1% of earth’s surface

Freshwater = 3% of total water supply of which 1% is available

Earth Basics

Bulk of land is located in the Northern Hemisphere = > 65%

Global Coordinate System

Latitude Longitude

Global Coordinate SystemLongitude (Meridians)-Run north and south and measure east

and west of the Prime Meridian (0o)

Closely associated with time and time zones.

Longitude

Global Coordinate SystemLatitude (Parallels)-Run east and west and measure north

and south of the equator (0o)

Closely associated with insolation and amount of daylight and darkness.

Latitude

Seven Parallels

0o

23.5 o N

23.5o S

66.5 o N

66.5 o S

North Pole

90o N

South Pole

90o S

Seven Parallels

Equator 0o degrees

Arctic Circle 66.5o N

Tropic of Cancer 23.5o N

Tropic of Capricorn 23.5o S

Antarctic Circle 66.5o S

North Pole & South Pole

Zones of Latitude

Equatorial Zone 0o - 7o N & S of Equator

Sub Arctic 55o - 66.5o N

Tropics 7o - 23.5o N

Tropics 7o - 23.5o S

Antarctic 66.5 o – 90o S

Sub Tropics 23.5o - 35o S

Sub Tropics 23.5o - 35o N

Middle Latitudes 35o - 55o N

Middle Latitudes 35o - 55o S

Sub Arctic 55o - 66.5o S

Arctic 66.5 o – 90o S

Revolution of Earth

June 21 – Summer Solstice Dec 21 – Winter Solstice

March 20– Spring Equinox

Sept 22 – Fall Equinox

Characteristics of Zones of Latitude

Equatorial Zone 0o - 7o N & S of Equator

Sub Arctic 55o - 66.5o N

Tropics 7o - 23.5o N

Tropics 7o - 23.5o S

Antarctic 66.5 o – 90o S

Sub Tropics 23.5o - 35o S

Sub Tropics 23.5o - 35o N

Middle Latitudes 35o - 55o N

Middle Latitudes 35o - 55o S

Sub Arctic 55o - 66.5o S

Arctic 66.5 o – 90o S