A Glimpse of World Geography

Geography is defined as a field of science devoted to the study of the lands, features, inhabitants, and various phenomena of the Earth.

Eratosthenes: The Father of Geography

Eratosthenes is widely recognized as the "Father of Geography" for his monumental contributions to the field.

• Background: He was born in Cyrene, which is located in present-day Libya in North Africa.

• Literary Work: He authored a three-volume work titled Geography, in which he mapped the entirety of his known world and divided the Earth into five distinct climate zones.

• Mathematical and Scientific Contributions:

  • He developed the fundamental concepts of latitude and longitude.

  • He was the first person to calculate the size of the Earth with a high degree of precision, achieving a minimal error of only $2\%$.

  • He calculated the Earth's axial tilt.

  • He is credited with possibly calculating the distance from the Earth to the Sun.

The Five Themes of Geography

The study of geography is organized around five core themes: Location, Place, Region, Human-Environment Interaction, and Movement.

1. Location

This theme refers to the specific position of a place on Earth and answers the question, "Where is it?"

• Absolute Location: This refers to the exact position of a place on the globe. It is determined by the intersection of lines of latitude and longitude.

  • Example (Africa): Africa is located between $37^\circ\text{ N}$ to $34^\circ\text{ S}$ in latitude and $17^\circ\text{ W}$ to $51^\circ\text{ E}$ in longitude.

  • Example (Greenland): Greenland is located between latitudes $59^\circ\text{ N}$ and $84^\circ\text{ N}$, and longitudes $10^\circ\text{ W}$ and $73^\circ\text{ W}$.

• Relative Location: This describes a place in relation to other places near or around it.

  • Insular Location: Refers to a place's location characterized by surrounding bodies of water.

  • Vicinal Location: Refers to a place's location as determined by the neighboring landforms and countries that border it.

2. Place

This theme explores the question, "What is it like to be in a certain place?" it is categorized into two sets of characteristics:

• Physical Characteristics: These refer to the natural environment, including landforms, water forms, climate, and ecosystems.

• Human Characteristics: These refer to elements reflecting human behavior, such as culture, architecture, and social practices.

3. Region

This theme asks, "What are the similarities or differences of these areas?"

• Formal Region: An area defined by official boundaries or uniform characteristics like similar climate, language, or culture.

• Functional Region: An area organized around a central point or node, linked by well-developed systems of transportation and communication (e.g., a metropolitan area).

• Vernacular Region: An area defined by how people mentally perceive a place (e.g., "the American South").

4. Human-Environment Interaction

This theme explores how humans and the environment affect each other through three specific lenses:

• Dependency: Humans rely on nature for their livelihood (e.g., resources like water or timber).

• Adaptation: How humans change their own lifestyles and behaviors to suit a new environment (e.g., wearing warmer clothes in cold climates).

• Modification: Actions taken by people to alter the environment to make it more suitable for their lives (e.g., building dams or leveling land).

5. Movement

This theme asks, "Why and how are places connected to each other?" It examines the migration of people, the transport of goods, and the flow of ideas.

Physical Features and Continental Drift

Continents are huge landmasses surrounded by sea or ocean. They comprise groups of countries categorized by their geographical locations.

• The Continental Drift Theory: Proposed in $1912$ by Alfred Wegener ($1880$-$1930$). He observed that the continents appeared to fit together and proposed they were once a single protocontinent called Pangaea (meaning "all lands"). Over time, these landmasses drifted apart to their current distribution.

Global Continents: Data and Specifications

1. Asia:

   • The largest continent on Earth, accounting for $30\%$ of the total land area.

   • Land Area: $44.58\,million\,km^2$.

   • Located primarily in the Eastern and Northern Hemispheres.

2. Africa:

   • The world's second-largest and second-most populous continent.

   • Land Area: $30,370,000\,km^2$ ($11,730,000\,sq\,mi$).

   • Renowned as a wildlife haven.

3. North America:

   • The third-largest continent.

   • Entirely within the Northern Hemisphere and almost entirely within the Western Hemisphere.

   • Land Area: $24.71\,million\,km^2$.

4. South America:

   • The fourth-largest continent.

   • Located entirely in the Western Hemisphere, mostly in the Southern Hemisphere with a small portion in the Northern Hemisphere.

   • Land Area: $17.84\,million\,km^2$.

5. Antarctica:

   • The southernmost continent and the site of the South Pole.

   • The fifth-largest continent, it is virtually uninhabited.

   • Land Area: $14.2\,million\,km^2$.

6. Europe:

   • The sixth-largest continent.

   • Located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere.

   • Land Area: $10.18\,million\,km^2$.

7. Australia/Oceania:

   • The seventh-largest continent.

   • Sometimes known in technical contexts as Sahul, Australinea, or Meganesia to distinguish the continent from the country of Australia.

   • Land Area: $7.692\,million\,km^2$.

Tectonic Boundaries and Landforms

Plate Tectonic Boundaries

There are three primary types of plate tectonic boundaries:

• Convergent Boundaries: Plates move toward each other.

• Divergent Boundaries: Plates move away from each other.

• Transform Boundaries: Plates slide past each other (e.g., the San Andreas Fault).

Types of Landforms

• Mountains: Sloping and highly elevated areas with a summit (highest point). They are formed by tectonic plates pushing land upward.

  • Fold Mountain: The most common type, formed by the folding of rock layers. Examples include Mt. Pulag, Mt. Apo, and Mt. Talinis.

  • Dome Mountain: Created when magma pushes up under rock layers without erupting, creating a dome-shaped uplift.

  • Volcanic Mountain: Formed when molten rock deep within the Earth erupts and piles up on the surface.

• Hill: An elevated landform with a rounded summit, lower and less steep than a mountain.

• Plateau: An elevated landform with a flat top and steep slopes on all sides (e.g., the Tibetan Plateau).

• Plain: A wide area of flat land. Plains cover more than one-third ($1/3$) of the Earth's surface.

• Basin: A hollowed-out landform on the Earth's surface that lacks an outlet for water to flow out.

• Valley: Flat land situated between mountains.

• Desert: A large, barren area with little to no rocky soil or vegetation. They can be classified as hot or cold.

Water Forms

Bodies of water are major components of physical geography. Major forms include:

• Oceans:

  • Pacific Ocean: Separates Asia from the Americas.

  • Atlantic Ocean: Separates the Americas from Europe and Africa.

  • Indian Ocean: Separates Asia from the Southern Ocean.

  • Southern Ocean: Surrounds Antarctica and separates it from other continents.

  • Arctic Ocean: Located around the North Pole.

• Sea: The next largest body of salt water after oceans, typically shallower than an ocean.

• River: A large body of flowing water. Longest rivers include the Nile (Africa) and the Amazon (South America).

• Bay: A body of water almost completely surrounded by land, except for a small opening.

• Gulf: Larger than a bay with a wider opening; a portion of the ocean that extends into the land.

Common Livelihoods by Geography

Livelihoods Under Landforms

• Agriculture: Farming crops such as rice, sugarcane, potatoes, barley, and tea.

• Animal Raising: Producing meat, milk, wool, and animals for transportation.

• Forestry: Harvesting timber, herbs, honey, firewood, and medicinal plants.

• Eco-Tourism and Trekking: Providing guiding services, homestays, and local product sales.

• Mining and Quarrying: Extraction of gold, copper, or limestone.

Livelihoods Under Water Forms

• Freshwater/Marine Fishing: Catching fish, crabs, squid, or shrimp.

• Irrigated Farming: Using river water to plant crops like rice and vegetables.

• Boat-making and River Transport: Construction of vessels for fishing or moving people/goods.

• Sand and Gravel Quarrying: Excavating materials from riverbeds.

• Trading and Port Services: Selling goods and offering transportation through maritime ports.