FOUNDATIONS OF GEOGRAPHY

The Science of Geography

geography from the Greek – geo and graphy

It has both spatial perspective and temporal perspective

The Study of Geography, cont

- Geographic Science is founded on five “themes”

location region place

movement human-earth relationships

- It is both a physical and social science

[see Fig 1.2: The content of geography]

(1) Cultural (Human) Geography

population; culture; ethnicity

(2) Physical Geography

meteorology; geomorphology

Both Subfields Study:

(1) Location

--- absolute and relative

(2) Characteristics of Places

--- physical landscape and cultural landscape

(3) Spatial Distributions and Spatial Patterns

Both Subfields Study:

(4) Spatial Interaction

links across the Earth surface

(5) Ever Changing Earth

(a dynamic system)

(6) Human Interactions With The Environment

Systems Theory / The Earth System

- The Earth is a system

- A system is a set of interrelated components / factors existing to carry out a function

--- a system is open or it is closed

- A system is conceptualized according to its components

Attempt to understand how these variables relate / affect / impact

- state (level) and rate

Systems are dynamic, but are viewed

point-in-time… Man needs an Earth in dynamic equilibrium

Systems are composed of “nested” subsystems

Earth is a Complex System

Complex systems are characterized by:

(1) strong (usually non-linear) interactions between components;

(2) complex feedback loop that make it difficult to distinguish cause from effect;

(3) significant time and space lags, discontinuities, thresholds, and limits;

(4) the inability to simply “add up”(aggregate)

small-scale behavior to arrive at large-scale results

Earth Subsystems

(1) Atmosphere

(2) Lithosphere

(3) Hydrosphere

(4) Biosphere

Models and Systems

Many systems are too complex to understand as they exist

… we create models in an attempt to simplify

… we must be careful not to become reductionist

Models may be:

(1) Physical

(2) Diagrammatic / Graphic

(3) Mathematical / Statistical / Computer generated

(4) Conceptual (ex: mental maps)

Environment-Ecology-Ecosystem

Geography is interested in relationships of Man-Environment / Spatial-Temporal

--- best studied through “impacts”

--- this is especially true for physical geography and the physical environment

Environment

physical, cultural and social aspects of our surroundings; affects our growth, way-of-life, etc.

… romanticized, environment is:

(1) our “canvas”: Man-Land Relationship

(2) our “paints”: Natural Resources

(3) our “work-in-progress”: Cultural Resources

Ecology

Ellen Swallow at M.I.T.

[have also heard the name Ernst Heinkel (latter 19th C) associated with coining this term]

Study of the relationships between organisms and their physical environment

Ecosystem

Ecological system

Community of organisms and their relation to the physical environment; a dynamic relationship

The Earth as a Planet: A Spherical Planet

We tend to think of the Earth as infinite

… obviously it cannot be

Unless we can circumvent light year distances, we are limited to the planet that we have

Size and Shape of the Earth

Throughout history Man has speculated about the Earth, its shape and our place in “everything”

Earth Mother

cosmologic civilizations

universalizing religions

Pythagoras (540 B.C)

theorized Earth as a sphere

Eratosthenes (circa. 247 B.C)

Greek climate scheme

“proved” the Earth is round

Earth is an oblate spheroid

(ellipsoid of rotation)

7900 mi x 7927 mi

Movements of the Earth

The Earth has three basic movements:

(1) rotation turning of Earth on polar axis

1o of arc every 4 min

1040 mph at Equator

0 mph at Poles

direction according to perspective

rotation, cont

We are not aware of rotational velocity:

(a) constant for all locations on Earth

(b) atmosphere rotates at same velocity

(c) no nearby objects for a frame of reference of motion

Rotation gives us circle of illumination

Someday Earth rotation will stop

(2) revolution – elliptical Earth movement around the sun

… Jan 3 at its perihelion

… July 4 at its aphelion

(3) galactic movement – movement of Earth, Sun and Solar System around the center of the Milky Way

Location and Time on Earth

- The ability of delineate location (absolute location) is fundamental to spatial perspective--- absolutely necessary for cause-and-effect; for location-relationship; for compare-and-contrast studies

- Verbal communication of location must have evolved early… particularly in the realm of the personal mental map

- Assigning location quickly developed religious and cosmological significance

- Historically, the most common representation of location has been the map or the globe

- Because of the importance of map making, the geographic field of cartography evolved

“the art that became a science”

Globes and Great Circles

- The globe represents that most perfect representation of the Earth currently available

- Most important is that a globe correctly represent the aspects of area and shape

--- because of this a globe allows illustration of significant concepts (day-night; seasonal change; etc)

- Globe has limitations:

(1) expense

(2) inconvenient shape

(3) lack of detail

Despite of their limitations globes serve as a good starting point for explaining the concepts of location… and this is what your text does

I. Great Circle – and imaginary line on the surface of the Earth that bisects the center of the Earth (any other circle is a small circle) [Fig 1.13]

--- represents largest circle possible on the Earth

I. Great Circle, cont--- the circumference of a great circle will be the circumference of the Earth (?)--- use:

(1) cuts Earth in ½ creating hemispheres(2) each hemisphere will be the

circumference of the Earth (?)(3) each is the shortest route of travel

around the Earth (great circle route)

Latitude and Longitude

A set of coordinate systems for deriving locations on the Earth (Cartesian coordinates) [Fig 1.10]

II. Latitude (1) latitude extends east-west and measure

angular distance north-south of the Equator great circle

(2) are circles when viewed in entirety(3) are parallel (equidistant) (4) 1o of latitude equals approx 70 mi of Earth surface distance

II. Latitude, cont

… can further subdivide degrees

1 min = 1.2 mi. ; 1 sec = 102’

(5) vary greatly in length, but do so in an orderly manner

(6) an unlimited number of parallels exist

(we use convenient numbers of them)

III. Longitude - In order to pinpoint east-west location, we must define a north-south measure --- this can be done by defining an

arbitrary N.-S. reference line running from pole-to-pole … problem is, which one?

- 1884 Greenwich, England was designated as the Prime Meridian (0o long)

III. Longitude, cont- Locations measured in degrees, minutes, seconds, east or west of Greenwich to a maximum of 180o (International Date Line) (1) meridians extend north-south and

measure distance east-west (2) each is a ½ circle with Polar endpoints (3) meridians are not parallel to each other

and converge at the Poles[so distance of degrees, minutes, seconds is latitude dependent]

III. Longitude, cont

(4) meridians always intersect at 90o

(5) an unlimited number of parallels exist

(we use convenient numbers of them)

With latitude and longitude we have effectively created a universal, transferable grid

Longitude and Time

Time Zones- Longitude has a special relationship in the determination of time- Problem of “local time” and “solar noon”- 1884 the International Meridian Conference established a system of time zones [Fig 1.15]

--- 24 zones of 15o longitude each, representing an hour period

- From 1884 the Prime Meridian and every 15th degree established the time for a time zone 7 ½o to either side of it

Maps and Map Projections

Maps are representations of the features / activities of Earth having advantages and disadvantages for use

Advantages(1) cheap to produce and transport(2) easy to use and make for special requests(3) ability to use at many scales

Disadvantagescannot represent circular/spherical area on flat map without distortion

… shape; area; distance; direction… distortion greater as region represented gets larger and/or gets further from the Equator

Map Essentials

Whatever the type of map, form of projection, ultimate use, etc; all maps share some essential features

(1) title - area and data depicted

(2) date - time frame of data depicted

(3) legend - key to symbolization used on map

(4) scale - statement of relationship of map distance-to-Earth distance

Global Positioning Systems

GPS – Newest way available to determine location on the Earth

--- takes advantage of orbiting satellites to triangulate a requested position

--- initially developed for the military, now potential utilization for any location / activity

Modern Mapping Technology

Computer Mapping and Geographic Information systems

Computer technology has revolutionized cartography

Computer technology allows accumulation and storage of unprecedented volumes of digital form information for instant retrieval, updating and perspective altering

Computer Mapping and Geographic Information systems, cont

Geographic Information Systems (GIS) - a computer-based technology that enters, analyzes,

manipulates and displays geographic information- marriage of computer cartography and data-base

management- potential to store/utilize massive amounts of data- organized into layers of information – “overlays”- super widespread applications

Downside to GIS is that accumulation of useable data can be expensive and exhaustive

Remote Sensing of the Environment- collection of data through a distance- “remote sensor” is a mechanical device

accumulating information across a distance- Utilizes visible light or radiant energy;

--- is “active” or “passive”; --- can be photographic or non-

photographic