This document provides an overview of key concepts in geography. It begins by defining geography and its two main divisions: physical geography, which deals with natural environments, and human geography, which examines human-environment interactions. Physical geography includes the study of landforms (geomorphology), oceans (oceanography), climate (climatology), life (biogeography), and the environment. The document then discusses human geography topics like population, urban areas, agriculture, and culture. It also explains concepts like the rotation and revolution of the Earth, which cause seasons, and types of eclipses like lunar and solar eclipses. In the end, it briefly mentions time zones and how local times differ globally.
2. Objectives
Introduction.
Rotation And Revolution And Change In Season.
Eclipses.
Latitude And Longitude.
World Time Zone Standard And Local Time Zone.
Finding Location On Map.
Direction And Scale OF Map.
Prepared By Awais Bakshy.
Geography.
Geographyis Greek word which mean’s earth description.
Geographydeals with the physical and humans aspects on the earth surface.
The relation between man and its environment is called geography.
Geographymainlydivided in two types.
1. Physical Geography.
2. Human Geography.
Physical Geography.
Physical geographydeals with the studyof processes and patterns in the natural
environment like the atmosphere, hydrosphere, biosphere, and Geosphere
No interference of man
Four Realms of Earth.
1. Land = Lithosphere=Geomorphology.
2. Air=Atmosphere=Climatology
3. Water=Hydrosphere=Oceanography
This All join Together to form Life.
4. Life=Biosphere=Bio Geography.
3. All above the realms combine to form environment.
5. Environmental Geography.
Physical Geography Divisions.
1. Geomorphology
2. Oceanography
3. Climatology.
4. Bio Geography.
5. Environmental Geography.
Geomorphology.
Geomorphology is the field concerned with understanding the surface of the Earth
and the processes by which it is shaped, both at the present as well as in the past.
Oceanography.
Oceanography is the branch of physical geographythat studies the Earth's oceans
and seas.
Climatology.
Climatology is the studyof the climate, scientificallydefined as weather conditions
averaged over a long period of time.
Bio Geography.
Biogeographyrefers to the distribution of various species and ecosystem
geographicallyand throughout geological time and space. Biogeographyis often
studied in the context of ecological and historical factors which have shaped the
geographical distribution of organisms over time.
Environmental Geography.
The branch of geographythat describes and explains the spatial aspects of
interactions between human individuals or societies and their natural environment.
Human Geography.
Human geographydeals with the study of people and their communities, cultures,
economies, and interactions with the environment.
4. Human Geography divisions.
1. Population geography.
2. Regional geography.
3. Urban geography.
4. Agriculture geography.
5. Medical geography.
6. Cultural geography.
7. Settlement geography
Demography or population geography.
Is the studyof human populations – their size, composition and distribution across
space – and the process through which populations change. Births, deaths and
migration are the ‘big three’ of demography, jointly producing population stabilityor
change.
Regional geography.
Regional geographyis a division of human geography. It focuses on the interaction of
different cultural and natural geofactors in a specific land or landscape.
Urban Geography.
With the development of urban cities worldwide, the branch urban geographycame
into playsince it enables researchers to studythese trends much more effectively.
In addition to this, these geographers are able to investigate potential locations that
are suitable for development for the tiniest of villages to sprout into the desired huge
cities.
Agriculture geography.
Agricultural geography is a division of human geography concerned with the spatial
relationships found between agriculture and humans.
Medical Geography.
The branch of human geographythat deal with the geographic aspects of heath and
health care .
5. Cultural Geography.
The Studyof the relationship between culture and place
Settlement geography.
Settlement geographyis a branch of geography that investigates the earth's
surface's part settled byhumans.
Rotation and Revolution.
What is Rotation?
When an object turns around an internal axis (like the Earth turns around its axis)
it is called a rotation
What is Revolution?
When an object circles an external axis (like the Earth circles the sun) it is called
a revolution.
Earths Movement.
There are two types of earth movement. 1) Rotation. 2) revolution.
Rotation and Revolution of earth.
Rotation of the earth.
Rotation is the movement of the Earth on its axis from west to east once in twenty
four (24) hours period. It is also called dailymotion or diumal. The earth axis which
runs from north to south and passes through the center of the earth. The speed of
rotation is 24, 855/24 hours or 1,038 miles/hr
One rotation completes in. 24 hours 56 minutes 4.1 seconds. This Period Called
Sidereal period.
Effects of Rotation of Earth.
1. Day and Night: As the earth rotates on its axis, half of the earth faces the sun
and half of the earth faces away from the sun. The half of the Earth that faces the
sun will experience day while the half of the Earth that faces away from the sun
will experience night.
6. 2. Coriolis Effect.
An effect wherebya mass moving in a rotating system experiences a force
(Coriolis force) acting perpendicular to the direction of motion and to the axis of
rotation. On the earth, the effect tends to deflect moving objects to the right in
the northern hemisphere and to the left in the southern and is important in the
formation of cyclonic weather systems
History.
Gustave Gaspard Coriolis (1792-1843).
Using just a pen, paper and mathematics, he figured out why the wind turns,
curves, and goes around in circles.
Then named his resulting discovery the Coriolis effect.
7. 3. Low And High Tide.
High and low tide is a result of the gravitational pull between the sun and the
moon. When the earth rotates, the sun and the moon pulls it, however, one of the
force is usuallystronger than the other. Hence, we will experience high and low
tide.
4. Wind speed and directions.
Wind on the earth comes from north, south, east and west direction. As the earth
rotates on its axis, different places will get stronger surge of wind as a result of
the speed of the rotation
Longest days and nights.
Northern southern
Hemisphere. Hemisphere
Longest day(short night) = June 22 December 22
Shortest day(longest night) = December 21 June 21
What is equator?
A line notionallydrawn on the earth equidistant from the poles, dividing the earth into
northern and southern hemispheres and constituting the parallel of latitude 0°
The equator divides the earth into half sphere or hemisphere.
Northern hemisphere.
The Northern Hemisphere is the half of Earth that is north of the Equator
8. Southern hemisphere.
The Southern Hemisphere is the half of Earth that is south of the Equator
Eastern hemisphere.
Eastern Hemisphere, the half that lies east of the prime meridian and west of
the 180th meridian
Western hemisphere.
Western Hemisphere, the half that lies west of the prime meridian and east of the
180th meridian
Equal Days and Nights.
Days and nights are equal at the equator throughout the year, because the circle of
illumination always divides the equator into two parts.
Days and night in Pakistan.
Longer days and shorter night: in June
Shorter days and longer nights: in December
Note………………………………….Note…………………………………Note……………………….Note………………..
Direction of Rotation.
1. Imagine yourself looking down on the north pole of the earth. From this
position, the earth is turning in a counterclockwise direction
2. Imagine yourself off in space, viewing the planet much as you would view a
globe in a library, with the north as you would view a globe in a library, with
the North Pole on top. The earth is rotating from left to right or in an eastward
direction.
Speed of Rotation. 1670 km/hr
Equatorial Diameter. 12,756km
Polar Diameter. 12,714km
9. One complete rotation with respect to the sun defines the solar day. The solar day
is divided in to 24 hr.
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Revolution of Earth and Change in Seasons.
Revolution is the movement of the earth around the sun, this last for 365 and ¼
days (365 days 5 hr 48 min and 45.51 seconds). Earth revolves around the sun in a
slightlyeccentric elliptical orbit once a year. The speed of earth’s revolution is
about 18 miles per hour. This motion is also called annual motion or yearly motion
because its take one solar year to complete the journey.
Effect of Revolution of Earth.
Causes of change in seasons.
How Seasons Change.
The earth’s axis is inclined at an angle 66 ½ degree to the plane of its orbit. As a
result of this, the earth is in different positions while revolving round the sun. during
the first half of the year the northern hemisphere tilts towards the sun resulting in
longer days and the summer season in the region during this period the southern
hemisphere experience winter. During the second half of the year the southern
hemisphere tilts toward the sun, and thus experience summer and northern
hemisphere experience winter during this period.
What is Equinox: Equinoxes are dates when nights and days are equal. During
these days the sun shines directlyover the equator March 21 is called vemal
equinox or spring equinox. September 23 is called autumnal equinox.
10. What is solstice: The time of the year when the difference between the length of
the days and the length of nights is the largest is referred to as solstice. During
these days the sun shines verticallyover a tropic.
1. On or around June 21 the north pole tilts towards the sun and the sun shines
directly over the tropic of cancer. This is called summer solstice.
2. On or around December 22 the earth is at the opposite end of its orbit. The
South Pole tilts towards the sun the North Pole away from it. This is called
winter solstice. In the northern hemisphere, days are longest and nights are
shortest during the summer solstice and alternatelythe days and night are
shortest and longest respectively during the winter solstice.
11. Note………………………Note…………………………………Note…………………………..Note………………………..Note.
The revolution of the earth around the sun the path where earth revolves around the
sun is elliptical that means the distance is different. When earth is nearest to the sun
at perihelion which occurs in January. When the earth is farthest away from the sun
at aphelion occurs in July.
12. Instant fact: very large in earth’s history(Between 4.5 and 4.3 billion years ago) a
mars sized object struck earth. The impact created tremendous heat and produced
orbiting debris that coalesced of form our moon. The impact also Knocked earth off
its axis of rotation to the present tilts 23.5 degree without such an impact.
Change in Seasons.
1. The earth revolves around the sun in 365 days.
2. The earth axis of rotation is tilted by23 ½ degree from normal on the plane of the
ecliptic.
3. The tilt of the earth axis points in a constant direction in heaven throughout its
journeyaround the sun.
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Four Seasons.
The annual motion of the earth cause four seasons .
1. Spring.
2. Summer.
3. Autumn.
4. Winter.
Spring.
13. Spring Equinox marks the beginning of spring on March 20/21. When it is spring in the
northern hemisphere it will be autumn in the southern hemisphere and the sun is
directly over the equator.
Summer.
Summer Solstice marks the beginning of summer on June 21/22. June 21 is the
longest day. When it is summer in the northern hemisphere it will be winter in the
southern hemisphere and the sun is directlyover the tropic of cancer
Autumn.
Autumn Equinox marks the beginning of autumn on September 22/23. When it is
autumn in the northern hemisphere it will be spring in the southern hemisphere and
the sun is directlyover equator.
Winter.
Winter Solstice marks the beginning of winter on December 21/22. December 21 is
the shortest day.
Eclipses.
What is Eclipse: An eclipse takes place when one heavenlybodysuch as a moon or
planet moves into the shadow of another heavenly body. There are two types of
eclipses on Earth: an eclipse of the moon and an eclipse of the sun.
Types Of eclipses.
1. Lunar Eclipses.
2. Solar Eclipses.
Lunar Eclipses.
The moon moves in an orbit around Earth, and at the same time, Earth orbits the sun.
Sometimes Earth moves between the sun and the moon. When this happens, Earth
blocks the sunlight that normallyis reflected by the moon. (This sunlight is what
causes the moon to shine.) Instead of light hitting the moon’s surface, Earth's shadow
falls on it. This is an eclipse of the moon a lunar eclipse. A lunar eclipse can occur
only when the moon is full. A lunar eclipse can be seen from Earth at night.
There are three types of lunar eclipses.
14. 1. Total lunar eclipses.
2. Partial lunar eclipses.
3. Penumbral Lunar.
Total Lunar Eclipses.
A total lunar eclipse occurs when the moon and the sun are on exact opposite
sides of Earth. Although the moon is in Earth's shadow, some sunlight reaches the
moon. The sunlight passes through Earth's atmosphere, which causes Earth’s
atmosphere to filter out most of the blue light. This makes the moon appear red
to people on Earth.
Partial Eclipses.
A partial lunar eclipse happens when onlya part of the moon enters Earth's shadow.
In a partial eclipse, Earth's shadow appears very dark on the side of the moon facing
Earth. What people see from Earth during a partial lunar eclipse depends on how the
sun, Earth and moon are lined up.
Penumbral Lunar Eclipses.
The Moon passes through Earth's penumbral shadow.
15. Note……………………Note………………………………………Note………………………..Note……………………….
A lunar eclipse usually lasts for a few hours. At least two partial lunar eclipses
happen every year, but total lunar eclipses are rare. It is safe to look at a lunar
eclipse.
Types Of Shadow.
Umbra: The first shadow is called the umbra. This shadow gets smaller as it reaches
Earth. It is the dark center of the moon’s shadow.
Penumbra: The second shadow is called the penumbra. The penumbra gets larger as
it reaches Earth.
People standing in the penumbra will see a partial eclipse.
People standing in the umbra will see a total eclipse.
Total Moon eclipse sometime called blood moon.
Danjon Scale.
End……………………………………….End…………………………………….End……………………………End……..
Solar Eclipses.
When the moon orbits Earth, it moves between the sun and Earth. When this happens,
the moon blocks the light of the sun from reaching Earth. This causes an eclipse of
the sun, or solar eclipse. During a solar eclipse, the moon casts a shadow onto Earth.
Types of Solar Eclipse.
1. Total Solar Eclipse.
2. Annular Solar Eclipse.
16. 3. Partial Solar Eclipse.
4. Hybrid Solar Eclipse.
Total Solar Eclipse.
A total solar eclipse is only visible from a small area on Earth. The people who see the
total eclipse are in the center of the moon’s shadow when it hits Earth. The sky
becomes very dark, as if it were night. For a total eclipse to take place, the sun, moon
and Earth must be in a direct line.
Partial Solar Eclipse.
This happens when the sun, moon and Earth are not exactlylined up. The sun appears
to have a dark shadow on onlya small part of its surface.
Annular Solar Eclipse.
An annular eclipse happens when the moon is farthest from Earth. Because the moon
is farther away from Earth, it seems smaller. It does not block the entire view of the
sun. The moon in front of the sun looks like a dark disk on top of a larger sun-colored
disk. This creates what looks like a ring around the moon.
Hybrid Solar Eclipse.
17. World Time Zone. Standard and Local Time.
Global Time.
Our Planet requires 24 hours for a full rotation with respect to the sun. Humans long
ago decided to divide the solar day into 24 units, called hours, and devised clocks to
keep track of hours in groups of 12. Yet, different regions set their clocks
differently—when it is 10:03 A.M. in New York, it is 9:03 A.M. in Chicago, 8:03 A.M. in
Denver, and 7:03 A.M. in Los Angeles. These times differ byexactly one hour. How did
this system come about? How does it work? Even in today’s advanced age, our global
time system is oriented to the Sun. Think for a moment about the Sun moving across
the sky. In the morning, the Sun is low on the eastern horizon, and as the day
progresses, it rises higher until at solar noon it reaches its highest point in the sky. If
you check your watch at that moment, it will read a time somewhere near 12
o’clock (12:00 noon). After solar noon, the Sun’s elevation in the sky decreases. By
late afternoon, the Sun hangs low in the sky, and at sunset it rests on the western
18. horizon. Imagine for a moment that you are in Chicago. The time is noon, and the Sun
is at or near its highest point in the sky. You call a friend in New York and ask about
the position of the Sun. Your friend will saythat the Sun has already passed
solar noon, its highest point, and is beginning its descent down. Meanwhile, a friend in
Portland will report that the Sun is still working its way up to its highest point. But a
friend in Mobile, Alabama, will tell you that the time in Mobile is the same as in
Chicago and that the Sun is at about solar noon. How do we explain these
different observations? The difference in time makes sense because solar noon can
only occur simultaneouslyat places with the same longitude. Onlyone meridian can
be directly under the Sun and experience solar noon at a given moment. Locations on
meridians to the east of Chicago, like New York, have passed solar noon, and
locations to the west of Chicago, like Vancouver, have not yet reached solar noon.
Since Mobile and Chicago have nearlythe same longitude, theyexperience solar
noon at approximatelythe same time. Figure 1.14 indicates how time varies with
longitude. Since the Earth turns 360° in a 24-hour day, the rotation rate is 360°/24
= 15° per hour. So 15° of longitude equates to one hour of time.
19. World Time Zone.
According to our map of the world’s time zones (Figure 1.16 ), the country spanning the
greatest number of time zones is Russia. From east to west, Russia spans 11 zones, but
groups them into eight standard time zones. China covers five time zones but runs on a
single national time using the standard meridian of Beijing.
A few countries, such as India and Iran, keep time using a meridian that is positioned midway
between standard meridians, so that their clocks depart from those of their neighbors by30
or 90 minutes. Some states or provinces within countries also keep time by 7 ½° meridians,
such as the Canadian province of Newfoundland and the interior Australian states of
South Australia and Northern Territory.
20. Standard Time Zone
We’ve just seen that locations with different longitudes experience solar noon at
different times. But what would happen if each town or cityset its clocks to
read 12:00 at its own local solar noon? All cities and towns on different
meridians would have different local time systems. With today’s instantaneous global
communication, chaos would soon result. Standard time simplifies the global
timekeeping problem. In the standard time system, the globe is divided into time
zones. People within a zone keep time according to a standard meridian that passes
through their zone. Since the standard meridians are usually 15 degrees apart, the
difference in time between adjacent zones is normallyone hour. In some
geographic regions, however, the difference is onlyone-half hour.
21. Figure 1.15 shows the time zones observed in northern North America. The United
States and its Caribbean possessions fall within seven time zones. Six zones
cover Canada. Their names and standard meridians of longitude are as follows:
Local Time Zone.
Local time is the time where you are, or where the event is, or where the person is
who is being talked about. In Portland, Oregon, where I am, right now it is midnight
local time, but in Naples, Florida, where myhusband is on business, it is 3 am local
time.
Latitude and Longitude of earth.
PARALLELS AND MERIDIANS
Imagine cutting the globe just as you might slice an onion to make onion rings
(Figure 1.4 A). Lay the globe on its side, so that the axis joining the North and
22. South Poles runs parallel to your imaginarychopping board and begin to slice.
Each cut creates a circular outline that passes around the surface of the globe.
This circle is known as a parallel of latitude, or a parallel. The Earth’s longest
parallel of latitude is the Equator, which lies midway between the two poles. We
use the Equator as a fundamental reference line for measuring position.
Now imagine slicing the Earth through the axis of rotation instead of across it, just as you
would cut up a lemon to produce wedges (Figure 1.4 B). The outlines of the cuts form
circles on the globe, each of which passes through both poles. Half of this circular outline,
connecting one pole to the other, is known as a meridian of longitude, or, more simply, a
meridian.
Meridians and parallels define geographic directions. When you walk directly north or south,
you follow a meridian; when you walk east or west you follow a parallel. There are an infinite
number of parallels and meridians that can be drawn on the Earth’s surface, just as there
are an infinite number of positions on the globe. Every point on the Earth is associated with a
unique combination of one parallel and one meridian. The position of the point is defined by
their intersection. Meridians and parallels are made up of two types of circles—great and
small (Figure 1.5 ). A great circle is created when a plane passing through the center of
23. the Earth intersects the Earth’s surface. It bisects the globe into two equal halves. A small
circle is created when a plane passing through the Earth, but not through the Earth’s center,
intersects the Earth’s surface. Meridians are actually halves of great circles, while all
parallels except the Equator are small circles.
Because great circles can be aligned in anydirection on the globe, we can always find
a great circle that passes through two points on the globe. As we will see shortly in
our discussion of map projections, the portion of the great circle between two points
is the shortest distance between them.
24. Latitude And Longitude.
We label parallels and meridians by their latitude and longitude. The Equator divides
the globe into two equal portions (the northern hemisphere and the southern
hemisphere). Parallels are identified by their angular distance from the Equator,
which ranges from 0° to 90°. All parallels in the northern hemisphere are
described by a north latitude, and all parallels south of the Equator are given as
south latitude (N or S).Meridians are identified by longitude, which is an angular
measure of how far eastward or westward the meridian is from a reference
meridian, called the prime meridian. The prime meridian is sometimes known as the
Greenwich meridian because it passes through the old Royal Observatory at
Greenwich, near London, England. It has a longitude value of 0°. The longitude of a
meridian on the globe is measured eastward or westward from the prime
meridian, depending on which direction gives the smaller angle. Longitude then
ranges from 0° to 180°, east or west (E or W). Used together, latitude and longitude
pinpoint locations on the geographic grid (Figure 1.8). Fractions of latitude or
longitude angles are described using minutes and seconds. A minute is 1/60 of a
degree, and a second is 1/60 of a minute, or 1/3600 of a degree. So, the latitude 41°,
27 minutes (‘), and 41 seconds (‘‘) north (lat. 41° 27’ 41’’ N) means 41° north plus
27/60 of a degree plus 41/3600 of a degree. This cumbersome system has
now largelybeen replaced by decimal notation. In this example, the latitude 41° 27’ 41’’
N translates to 41.4614° N.
25. Degrees of latitude and longitude can also be used as distance measures. A degree of
latitude, which measures distance in a north-south direction, is equal to about 111 km
(69 mi). The distance associated with a degree of longitude, however, will be
progressively reduced with latitude because meridians converge toward the poles.
For example, at 60° latitude, a degree of longitude has a length exactly half of that at
the Equator, or 55.5 km (34.5 mi).
26. Finding Location on Map and Globe.
Map: A map is a drawing of a particular area such as a city, a country, or a continent,
showing its main features as they would appear if you looked it them from above.
Globe: A spherical representation of the earth, a celestial body, or the heavens.
Location: The terms location and place in geography are used to identify a point or an
area on the Earth's surface or elsewhere.
Types of Location:
27.
28. Directions and Scales of maps.
Directions of Map:
Types of Direction.
1. True Directions/ Geographical Location.
Geographic location refers to a position on the Earth. Your absolute geographic
location is defined by two coordinates, longitude and latitude. These two
coordinates can be used to give specific locations independent of an outside
reference point. Relative location, on the other hand, defines a location in terms
of another. For example, Lille is north of Paris.
2. Magnetic Directions.
GPS (GLOBAL POSITIONING SYSTEM) is a magnetic Direction.
Primary Directions.
Secondary Directions.
Tertiary Directions.