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Chapter I: The nature of physical geography- Spheres of study

1. Atmosphere, lithosphere and hydrosphere

2.Breaking it down further: biosphere and ecosystem

Characteristics of geography

i. Geography is integrative.

- It borrows from either disciplines or integrates them, in its study.

- GEOGRAPHY touches on chemistry, biology, and many other sciences.

- Physical geography studies locations, distributions an patterns

- Cartography will look at the reading and of maps.

- Spatial understanding also looks at how changes occur on the earth's

surface.

ii. Physical geography is holistic - looking at the big picture.

- The depletion of one species can lead to problems in another part of

the earth.

- Physical geography is concerned with change

- For many natural processes, the change is predictable

- The flooding of the river Nile led to the growth of one of the earth's

greatest civilizations.

iii. Lastly, geography is system-oriented

Systems

- Geography divides the study into systems.

1)Morphological system

*Morphology = change

- Concern of results of the changes

2)To understand the energy used to create the change we look at

cascading systems

2a) Open cascading systems are systems that receive energy fromoutside the system

- One could look at a forest as an open cascading system

- The energy comes from solar energy and fuels the processes that

generate the forest.

- Energy flows in and out of the system

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2b) or from a different perspective, one could look at the water cycle

as a closed cascading system

- The water molecules circulate in a finite space - a loop

- Ecosystems look at the interrelation between the elements of a

systems

- Here one can see how everything is connected and influenced by

things around.

- The removal of one seemingly insignificantly species can have dire

repercussions on the whole ecosystem.

- Lastly, the influence of human interference cannot be understood

3)Here we look at altered systems.

- These are the systems that are changed or altered through human

interference.

- The building of a pier and breakwater on a private beach disrupts the

natural flow of sand and has consequences down the line.

Geological time

- Time is an important issue for geographers

- Geological time however is much different from type of time we are

used to understanding

- It's incredibly fast

- The Earth is approximately 4.5 - 5 billion years old

- It all obeys the well established laws of science

- Because of the vast age of the earth in comparison to our brief time

on the planet, scientists needed a way to validate these theories

- Much of scientific discovery is based on direct observation

- Sometimes when direct observation is not possible, we rely on past

experience

- Our understanding of the basic physical laws help us to make theories

about how things develop- Here we use the law of Uniformitarism

- Simply put, we can make assumptions on processes based on an

understanding of how things work.

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- since we cannot stay and observe the changes water makes on the

surface of the earth over hundreds of years, we can make

assumptions based on visible forces around us

- We have also considered that some changes occur rapidly

- When an ice dam burst in the last ice age, the sudden release of

water physically altered the surface of the earth in a sudden and

dramatic way.

- The sudden changes are called catastrophic events

- they could be the sudden eruption of a volcano, a flash flood or an

earthquake

- They alter the landscape in a sudden and dramatic fashion.

Gaia Hypothesis

- While many scientists view the earth and the changes as being

separate processes, the Gaia Hypothesis states that we cannot

ignore the influence of the living things on the earth

- We know that humans have a great capability to alter the

environment

- Even a mountain sheep walking along the same path for years can

alter the environment.

- Simply states, the Gaia Hypothesis states that we are not separate

from our environment and therefore, to study the geographic

processes that go to forming and shaping our earth, we must also

look at our influence on our environment