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Etymology and Definition of Geography

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• Etymological Origin: The term "Geography" (Heograpiya) is derived from two Greek words:

  • Geo: Meaning "earth" (daigdig).

  • Graphia: Meaning "description" (paglalarawan).

• Scientific Definition: Geography refers to the scientific study of the physical characteristics of the earth.

• Scope of Study: The discipline covers several key areas of the physical and biological world:

  • Landforms (Anyong Lupa) and Water Bodies (Anyong Tubig).

  • Natural Resources (Likas na Yaman).

  • Climate and Weather (Klima at Panahon).

  • Flora: Plant life distributed across the globe.

  • Fauna: Animal life distributed across the globe.

  • Human Interaction: The distribution and interaction of humans and other organisms with their environment.

The Five Themes of Geography

In $1984$, the National Council for Geographic Education and the Association of American Geographers established five interconnected geographical themes. The goal was to simplify the study of geography as a social science and help people understand the world they inhabit.

• Location (Lokasyon): Refers to the position of places on the earth. There are two methods of determination:

  • Absolute Location: Uses imaginary lines such as latitude and longitude to form a grid. The intersection of these lines determines the exact coordinate of a place.

  • Relative Location: Based on surrounding landmarks, including landforms, water bodies, and man-made structures.

• Place (Lugar): Refers to the unique characteristics of a specific site. There are two ways to describe it:

  • Physical Characteristics: Includes climate, landforms, water bodies, and natural resources.

  • Human Characteristics: Includes language, religion, population density, culture, and political systems.

• Region (Rehiyon): A part of the earth unified by similar physical or cultural characteristics.

• Human-Environment Interaction (Interaksiyon ng Tao at Kapaligiran): The relationship between humans and the physical features of their location. This involves:

  • The environment as a provider of human needs.

  • Human adaptation to environmental changes.

• Movement (Paggalaw): The transfer of people, things, and natural events (like wind and rain) from one place to another. It is measured by three types of distance:

  • Linear (Lineyal): Physical distance—how far away a place is.

  • Time (Oras): How long the travel takes.

  • Psychological: How the distance is perceived based on the traveler's outlook.

Earth's Position and Internal Structure

• The Solar System: Earth is one of eight planets orbiting the Sun. The Sun is the primary source of energy for all life (plants, animals, humans) and influences weather, waves, rain, and climate. Photosynthesis in plants relies on sunlight, which in turn produces oxygen for living beings.

• Internal Composition: 1 1Crust: The hard, rocky outer layer. Its thickness ranges from $30\,km$ to $65\,km$ under continents, but it is only $5\,km$ to $7\,km$ thick under the oceans.

  • Mantle: A layer of extremely hot rock. Parts of it are soft and molten.

  • Core: The innerm ost layer composed of metals, specifically iron and nickel.

• Plates: The earth has large masses of solid rock called plates. They float on the mantle and move very slowly, approximately $5\,cm$ ($2\,inches$) per year. This movement causes earthquakes, volcanic eruptions, and the formation of mountains (e.g., the Himalayas).

• Hemispheres: The earth is divided into four halves:

  • Northern and Southern Hemispheres: Divided by the Equator.

  • Eastern and Western Hemispheres: Divided by the Prime Meridian.

Quantitative Data of the Earth

• Mass: approximately $5.9736 \times 10^{24}\,kg$.

• Estimated Age: $4.6\,billion$ years.

• Population (2009 data): $6,768,167,712$.

• Total Surface Area: $510,066,000\,km^2$.

• Land Area: $148,258,000\,km^2$ (approx. $29.1\%$).

• Water Area: $361,419,000\,km^2$ (approx. $70.9\%$).

• Water Type Distribution: $97\%$ salt water, $3\%$ fresh water.

• Circumference at the Equator: $40,066\,km$.

• Circumference at the Poles: $39,992\,km$.

• Diameter at the Equator: $12,753\,km$.

• Diameter at the Poles: $12,710\,km$.

• Radius at the Equator: $6,376\,km$.

• Radius at the Poles: $6,355\,km$.

• Orbital Speed: $66,700\,mph$ or $107,320\,km/h$.

• Orbital Period (Year): $365\,days$, $5\,hours$, $48\,minutes$, and $46\,seconds$.

Coordinate Systems: Longitude and Latitude

• Longitude: Angular distance measured from the Prime Meridian ($0^{\circ}$) located in Greenwich, England. These are "great circles" running from the North Pole to the South Pole.

  • International Date Line (IDL): Located at $180^{\circ}$ longitude in the middle of the Pacific Ocean. Crossing this line changes the calendar date.

• Latitude: Angular distance measured North or South of the Equator ($0^{\circ}$). The Equator divides the Earth into the Northern and Southern Hemispheres.

  • Tropic of Cancer: Located at $23.5^{\circ}\,N$; the northernmost point where the sun shines directly.

  • Tropic of Capricorn: Located at $23.5^{\circ}\,S$; the southernmost point where the sun shines directly.

  • Arctic Circle: Located at $66.5^{\circ}\,N$.

  • Antarctic Circle: Located at $66.5^{\circ}\,S$.

  • North Pole: $90^{\circ}\,N$.

  • South Pole: $90^{\circ}\,S$.

• Longitude: Angular distance measured from the Prime Meridian ($0^{\circ}$) located in Greenwich, England. These are "great circles" running from the North Pole to the South Pole.

  • International Date Line (IDL): Located at $180^{\circ}$ longitude in the middle of the Pacific Ocean. Crossing this line changes the calendar date.

• Latitude: Angular distance measured North or South of the Equator ($0^{\circ}$). The Equator divides the Earth into the Northern and Southern Hemispheres.

  • Tropic of Cancer: Located at $23.5^{\circ}\,N$; the northernmost point where the sun shines directly.

  • Tropic of Capricorn: Located at $23.5^{\circ}\,S$; the southernmost point where the sun shines directly.

  • Arctic Circle: Located at $66.5^{\circ}\,N$.

  • Antarctic Circle: Located at $66.5^{\circ}\,S$.

  • North Pole: $90^{\circ}\,N$.

  • South Pole: $90^{\circ}\,S$.

Continental Drift and the Seven Continents

• Continental Drift Theory: Proposed by Alfred Wegener, a German scientist. He suggested that the continents were once joined in a supercontinent called Pangaea, surrounded by the Panthalassa Ocean.

• Timeline of Separation:

  • $240\,million$ years ago: Existence of Pangaea.

  • $200\,million$ years ago: Pangaea split into Laurasia (North) and Gondwana (South).

  • $65\,million$ years ago: Continents continued to separate; India began moving toward Asia.

  • Present Day: Continents continue to drift; North America and Europe move away from each other by about $2.5\,cm$ annually.

The Seven Continents

1. Asia: The largest continent, covering approximately $1/3$ of the world's total land area. Includes China (most populous country) and Mt. Everest ($8,848\,m$).

2. Africa: Known for having the most countries. Features the Nile River (longest river) and the Sahara Desert (largest desert). Major supplier of gold and diamonds.

3. North America: Triangle-shaped, defined by the Appalachian Mountains (East) and Rocky Mountains (West). Features the Hudson Bay and Gulf of Mexico.

4. South America: Triangle-shaped, narrowing toward Cape Horn. Home to the Andes Mountains, which stretch $7,240\,km$ ($4,500\,miles$).

5. Antarctica: The only continent covered entirely by ice (avg. thickness of $2\,km$). No permanent human residents, only scientists. Rich in sea mammals and fish.

6. Europe: Approximately $1/4$ the size of Asia, making up $6.8\%$ of the world's land area. It is the second smallest continent.

7. Australia and Oceania: Australia is both a country and the smallest continent. It has been isolated for $50\,million$ years, leading to unique species like the Kangaroo, Koala, and Platypus.

Tectonic Activity and Earthquakes

• Pacific Ring of Fire: An area where the boundaries of the Asia, North America, and South America plates meet. It contains $75\%$ of the world's active volcanoes ($540$ known eruptions in history).

• Notable Volcanic Eruptions:

  • Tambora ($1815$): $92,000$ deaths.

  • Krakatoa ($1883$): $36,000$ deaths.

  • Mt. Pelee ($1902$): $30,000$ deaths.

• Notable Earthquakes:

  • China ($1556$): $830,000$ deaths.

  • Japan ($1923$): $143,000$ deaths.

  • China ($1976$): $242,000$ deaths.

  • Sumatra ($2004$): $227,898$ deaths.

  • Haiti ($2010$): $222,570$ deaths.

Climate and Geography

• Climate (Klima): The long-term condition of the atmosphere in a specific region.

• Factors affecting climate:

  • Latitude (proximity to the Equator).

  • Season.

  • Distance from the ocean.

  • Elevation/Altitude (height above sea level).

• Significance: Earth is the only planet capable of sustaining life due to its atmosphere and suitable levels of sunlight, heat, and water.

Topography: Landforms and Water Bodies

• Topography: The physical characteristics of a place or region.

• Historical Impact: Early civilizations emerged near river valleys, such as the Tigris-Euphrates, Indus, and Huang Ho in Asia, and the Nile in Africa.

• Major Mountain Peaks:

  1. Everest: $8,848\,m$ (Nepal/Tibet).

  2. K-2: $8,611\,m$ (Pakistan).

  3. Kangchenjunga: $8,586\,m$ (Nepal/India).

  4. Lhotse: $8,511\,m$ (Nepal).

  5. Kilimanjaro: $5,895\,m$ (Highest in Africa).

  6. Elbrus: $5,642\,m$ (Highest in Europe/Russia).

• The World's Oceans:

  • Pacific Ocean: $155,557,000\,km^2$. Deepest part: Mariana Trench ($35,840\,ft$).

  • Atlantic Ocean: $76,762,000\,km^2$. Deepest part: Puerto Rico Trench ($28,232\,ft$).

  • Indian Ocean: $68,556,000\,km^2$. Deepest part: Java Trench ($23,376\,ft$).

  • Arctic Ocean: Smallest recognized ocean.

  • Southern Ocean: Recognized by the International Hydrographic Organization in $2000$. It surrounds Antarctica and reaches up to $60^{\circ}\,S$ latitude. Deepest part: South Sandwich Trench ($23,736\,ft$).

• Major Seas: South China Sea, Caribbean Sea, and Mediterranean Sea.

Questions & Discussion

• Question: What race did the Malays originate from?

  • Answer: Austranesian.

• Question: Which destructive typhoon hit the Philippines on November 8, 2013?

  • Answer: Yolanda.

• Question: What is the climate of the Philippines?

  • Answer: Tropical.

• Question: Which country is west of Chad?

  • Answer: Niger.

• Question: How can one show understanding of the heritage provided by ancient civilizations that succeeded despite environmental challenges?

  • Answer: (Implicit) Through studying and preserving the methods they used to adapt to and utilize their physical geography.