What is Geography?Geography is a representation of the whole known world together with the phenomena which are contained therein.

Ptolemy, Geographia 2nd Century A.D.

Geography is the science of place. Its vision is grand, i ts view panoramic. It sweeps the surface of the Earth, charting the physical, organic and cultural terrain, their areal differentiation, and their ecological dynamics with humankind. Its foremost tool is the map.

Leonard Krishtalka, Carnegie Museum of Natural History, 20th Century A.D.

What is Geography?Geography is the study of WHAT IS WHERE, HOW IT GOT THERE, and WHY WE CARE?

Five “Key Spatial Themes” of Geography

1. Location – specific location, where?

2. Place – unique properties of a place

3. Movement – diffusion, communications

4. Region – an area’s uniform characteristics

5. Human-Earth Relationships – human interaction with an environment

What is Physical Geography?

Geography is a bridge between the natural and social sciences. Geography is a holistic and synthesizing science.

Physical GeographyNatural Science Human Geography

Rocks and Minerals Population Landforms Settlements Soils Economic Activities Animals Transportation Plants Recreational Activities Water Religion Atmosphere Political Systems Rivers and Other Water Bodies Social Traditions Environment Human Migration Climate and Weather Agricultural Systems

GeotechniquesGIS, GPS, Remote-Sensing, Cartography

Fields of Physical GeographyGeomorphology - studies the various landforms on the Earth's surface.

Pedology - is concerned with the study of soils and their relationship to vegetation and farming.

Biogeography - is the science that investigates the spatial relationships of plants and animals.

Climatology - studies the effects of weather on life and examines the circulation of the atmosphere over longer time spans.

Cartography - the art and science of making maps.

Cartography: The Art and Science of Mapmaking

(Click for more info)

REMOTE SENSING (click here for more info)

Aerial Photosof GCC (click)

Geographic Information Science (GIS) GIS is "an organized collection of computer hardware, software,

geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of

geographically referenced information."

Click on the map above to use the National Atlas of the United States.

La Conchita Landslide, January 2005REMOTE SENSING

Geographic Information Systems (GIS) – click for info

• Latest World Earthquakes Map

• National Atlas of the United States

Jobs in GeographyAerial Photo Interpreter Facilities Planner Land Developer

Site Researcher Agricultural Extension Agent Forestry Technician

Land Economist Soil Conservationist Air/Water Quality Control Manager

Geographer Land-Use Analyst Surveyor

Cartographer Geographic Area Specialist Location Expert

Systems Analyst Cartography Compiler Geographic Attache'

Map Analyst Teacher Climatologist

Geographic Information Systems Map Curator/Librarian Traffic Manager

Coastal Zone Manager Geophysics Assistant Map Editor

Transportation Analyst Community Developer Hazardous Waste Planner

Market Research Analyst Transportation Manager Computer Mapper

Health Services Planner Natural Resources Spec. Travel Agent/Specialist

Computer Programmer Health Services Organization Manager Outdoor Guide

Urban/Regional Planner Demographer Hydrologist

Park Ranger Weather Forecaster Earth Scientist

Industrial Developer Peace Corp Volunteer Wildlife Manager

Ecologist Industrial Planner Property Manager

Writer/Author Editor Intelligence Agent

Public Utilities Specialist Zoning Investigator Env. Impact Analyst

International Business Rep Real Estate Agent/Broker/Appraiser Environmental Quality Specialist

International Investment Analyst Remote Sensing Analyst College/University Professor

International Investment Analyst Remote Sensing Analyst College/University Professor

Famous Geography Students

Mother Teresa - Taught Geography and History in Calcutta for 15 Years

Prince William of Wales – Majored in Geography at University of Saint Andrews, Scotland

Michael Jordan – Majored in Cultural Geography at University of North Carolina, Chapel Hill

Immanuel Kant – the famous philosopher also taught everything from geography to physics and anthropology.

Fieldwork: Geographers as Modern Explorers and Observers

My Personal Travelshttp://www.glendale.edu/geo/reed/general/personal.htm

Introduction to the Earth

Introduction to the Earth

Introduction to the Earth

•The Location, Size, and Shape of the Earth

•The Environmental Spheres

•The Geographic Grid

The Solar System

MercuryVenus

Mars

Uranus

Jupiter

Saturn

Neptune

Earth

The Environmental SpheresLithosphere - describes the solid inorganic portion of the Earth (composed of rocks, minerals and elements). It can be regarded as the outer surface and interior of the solid Earth.

The Environmental SpheresAtmosphere - is the vast gaseous envelope of air that surrounds the Earth. Its boundaries are not easily defined. The atmosphere contains a complex system of gases and suspended particles that behave in many ways like fluids. Many of its constituents are derived from the Earth by way of chemical and biochemical reactions.

The Environmental SpheresHydrosphere - describes the waters of the Earth (see the hydrologic cycle). Water exists on the Earth in various stores, including the atmosphere, oceans, lakes, rivers, soils, glaciers, and groundwater. Water moves from one store to another by way of: evaporation, condensation,runoff, precipitation, infiltration and groundwater flow.

The Environmental SpheresBiosphere - consists of all living things, plant and animal. This zone is characterized by life in profusion, diversity, and ingenious complexity. Cycling of matter in this sphere involves not only metabolic reactions in organisms, but also many abiotic chemical reactions.

All of these spheres are interrelated by dynamic interactions (biogeochemical cycling)

The Size and Shape of the EarthEarth Dimensionsdiameter: 8,000 miles (12,900 km) circumference = ¶ d or 3.14 x 8,000 = 25,000 miles

Dead Sea – 1378 ft. below sea levelMt. Everest – 29035 ft.

Seen from space, the earth is essentially completely smooth. In fact, i f the radius of earth was a 30 story building, Mt. Everest would be only a single brick in height.

The Size and Shape of the EarthPythagorous (ca. 580 - 500 B.C., Greek), the first to note earth’s shape, assumed spherical perfection. Sir Isaac Newton (1687) reasoned that sphere not possible since earth rotation is maximized at the equator and this should produce a ‘bulge.’ He called earth an oblate spheroid (think of spinning water balloon; Jupiter is egg-shaped enough to be noticeable through inexpensive telescope).

7900 miles

7927 miles

N

The Equator divides the world into Northern and Southern Hemispheres.In the Western world, sailors have traditionally undergone sometimes brutal initiation ceremonies when first crossing the equator. The rituals often include dressing in drag.

The Geographic GridLatitude - angular measurement of distance north or south of the Equator.

Range: 0 - 90 degrees N or S

1o latitude = approx. 69 miles (25,000 mi. /360o).

Important ParallelsParallels of Latitude - Imaginary lines that connect points of equal

latitude, thus slicing the earth into equal “layers” like on a wedding cake.

The seven latitudes noted at right represent parallels where the sun’s rays strike the earth in unique and important ways on specific days of the year.

The Geographic GridLongitude the angular measurement of distance east or west of the Prime Meridian or Greenwich Meridian.

Maximum value reached at International Date Line (180O E or W)

The Prime Meridian, the zero measure of longitude, is a meridian that passes through the North Pole, South Pole, and Greenwich, England.

The Geographic GridLongitude the angular measurement of distance east or west of the Prime Meridian.

Range: 0o - 180o E or W

East-west width of 1O longitude for selected western North American cities:

San Diego (32.5 N) = 57 milesSan Francisco (38 N) = 54 milesSeattle (48 N) = 46 milesAnchorage (60 N) = 35 milesNorth Pole (90 N) = ?

Length of a Degree ofLongitude

Los Angeles County: 34o N, 118o W

Each degree is divided in 60 minutes(‘), thus we can locate Glendale at: 34o 10’ N, 118o 14’ W

Each minute is further divided into 60 seconds(‘’), thus we locate Glendale College at:34o 10’ 03” N, 118o 13’ 41” W

At this point we are accurate to within 100 ft2.

Degrees, Minutes, Seconds

Geographic Names Information Server

Earth-Sun RelationshipsThe Reasons for the Seasons

Solar Radiation• The earth intercepts less than one two-billionth of

the energy given off by the sun.• However, the radiation is sufficient to provide

99.9% of the energy that heats the earth / drives our climate.

• Photosynthesis provides the energy for nearly all earth processes.

Radiation Receipt• Solar radiation is received as

parallel rays of energy (“line of sight, speed of light”)– Earth’s diameter is 12,765 km– Sun’s diameter is 1,390,000

km (over 100 times that of the

Earth)

So is the receipt of radiation the same everywhere on Earth?

Why is i t hot in the tropics and cold at the poles?

The Earth is curved and this cause differing angles of

incidence.

Intensity of incoming solar radiation (insolation) is related to angle of incidence. Higher angles = higher intensity.

Does our distance from the sun throughout the year cause

seasons?

The line marking the shortest distance between the Sun and Earth's orbit is called the perihelion and is 91,500,000 miles long. The line marking the greatest distance between the Sun and Earth's orbit is called the aphelion and is 94,500,000 miles long.

Rotation of the Earth

• Rotate west to east or ‘counter-clockwise’ (when viewed from the North Pole)– sunset and sunrise

• Rotation period is 24 hours per solar day (23 hours 56 minutes with respect to other stars)

• Axis points to Polaris

Tilt of the earth on its axis. • The earth is tilted 23.5º from perpendicular to the plane of the

ecliptic.• Tilt is currently constantly toward Polaris

What causes the seasons?

• 23.5 O tilt of the earth axis from perpendicular to the plane of the ecliptic

• revolution of the earth around the sun

• polarity (axial parallelism)

Tilt of the earth on its axis. • The earth is tilted 23.5º from perpendicular to the plane of the

ecliptic.• Tilt is currently constantly toward Polaris

SOLSTICESSUMMER, JUNE 21WINTER, DECEMBER 21

Where are the overhead rays of the sun on these days?

Which parts of the earth are in darkness and light? For how long?

Solstice -when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.

EQUINOXES - the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length VERNAL, MARCH 21 AUTUMNAL, SEPTEMBER 21

Effects of the Seasons• Changes in solar altitude• Changes in day length• Changes in apparent solar intensity• Changes in temperature

All of these changes are most extreme at high latitudes and minimized at the equator.

90o N

E W

N

Of W

N of E

S of W

S of E

Annual Change in Noontime Solar Altitude

1 of 2

What is the change in height from the solstice to the equinox?

The total annual change?Summer Solst ice

Winter Solst ice

Equinox

E W

N of E

S of E

Annual Change in Noontime Solar Altitude

2 of 2

23.5O

23.5O

Summer Solst ice

Winter Solst ice

Equinox

Total annual change: 47O

sunrise sunsetS of W

N of W

Thought question: How high in the sky will the sun be in Glendale at noon on December 21?

E NN

Annual Change in Noontime Solar Altitude Total annual change: 47O

sunrise sunset

This diagram was created for Memphis, Tennessee (350 N).

How would it be different for Glendale, California?

How about Quito, Ecuador?

And what about Fairbanks, Alaska (650 N)?

Effects of the Seasons• Changes in solar angle• Changes in day length

All of the above lead to:• Changes in temperature • Changes in apparent solar intensity

All of these changes are most extreme at high latitudes and minimized at the equator.

Key Points• Size and Shape of Earth• Latitude and Longitude• Explain the basic earth-sun relationships• Equinoxes, solstices and the relationship among

– seasons– the latitude of the sun’s direct rays, and – the intensity of solar radiation received– changes in Daylight and Darkness