Geography: Introduction to Earth and The Geographic Grid (Latitude & Longitude)

Introduction to Earth

• Focus: Welcome to Week 1 Part 1 on Geography and the Earth, including physical features, environmental change, and the geographic grid.

• Core idea: Geography describes the Earth, its features, and how they vary across space.

Geography: What is Geography?

• Geography is the description of the Earth.

• Greek origin: geography =

  • location and distribution of things (spatial aspect)

  • how things differ from place to place

  • what makes a certain place unique

• Visual aid mentioned: A global perspective image often referred to as the "Blue Marble" (Earth) by Suomi NPP, 2012; Credit: NASA/NOAA.

• Examples of geographic inquiry:

  • What makes San Francisco unique? Why it is distinctive due to its location near the Pacific Ocean, its Mediterranean climate, presence of the San Andreas Fault, and the Silicon Valley.

What makes San Francisco unique? (Example)

• Proximity to the Pacific Ocean

• Mediterranean climate

• San Andreas fault

• Silicon Valley (technology hub)

Geographic data and imagery (Beijing/Jinan/Seoul, etc.)

• Geographic analysis relies on imagery and data sources:

  • Data sources cited: SIO, NOAA, U.S. Navy, NGA, GEBCO

  • Imagery sources: Landsat, Copernicus

  • Data providers and organizations: LDEO-Columbia, NSF, NOAA

• Example locations mentioned (illustrative of global coverage):

  • Beijing, Jinan, Nanjing, Shanghai, Fukuoka, Osaka, Sapporo, Seoul, Pyongyang, Dalian, Tokyo, etc.

• Imagery details noted: Imagery date (e.g., 12/31/2020) and coordinates/elevation for specific locations (e.g., 39°14'33.11" N 117°20'46.38" E, elev 16 ft).

What makes Kentucky unique? (Another example)

• Kentucky is used as a case study for regional uniqueness in geography.

Elements of Geography (Overview)

• Natural Science (Physical Geography) vs. Human Geography

  • Physical Geography includes: Landforms, Rocks & Minerals, Water, Weather & Climate, Plants

  • Human Geography includes: Population, Animals, Soil, Food, Economic Activities, Languages, Religions, Political Systems, Settlements, Social Science

Global Environmental Change

• Definition: Both natural and human-caused processes currently altering landscapes worldwide.

• Emphasis: Growing recognition of how human activities increasingly alter the environment.

Global Environmental Change (Case Illustrations)

• Beijing, China: Air pollution red alert warnings (e.g., Dec 19, 2015 article) highlighting severe smog and health concerns.

• Seoul, South Korea: Noted for high-level warnings when pollution reaches dangerous levels.

• The content underscores the real-world impact of environmental change on urban air quality.

Featured National Parks (Examples of places studied in environmental geography)

• Glacier, Mt. Rainier, Crater Lake, Yellowstone, Grand Teton, Badlands, Point Reyes, Isle Royale, Cape Cod, National Mall, Rocky Mountain, Shenandoah, Yosemite, Bryce Canyon, Canyonlands, Mammoth Cave, Death Valley, Grand Canyon, Great Smoky Mountains, Assateague Island, Denali, Hawai'i Volcanoes, Everglades

Environmental Spheres (Four Interconnected Spheres)

• Lithosphere: rocks and mineral matter

• Atmosphere: mixture of gases

• Hydrosphere: water in all its forms; cryosphere = frozen water

• Biosphere: all parts where living organisms exist

• Interactions: The spheres are interconnected and influence each other (e.g., atmosphere affects hydrosphere and biosphere, etc.).

The Geographic Grid: Latitude and Longitude

• Purpose: Provide precise location on Earth to describe geographic features.

• Graticule: The Earth's grid system with two sets of lines:

  • First set: Earth's rotation axis line through the North Pole and South Pole.

  • Second set: Imaginary lines through the equator.

• Use: Allows us to describe location with latitude and longitude.

The Geographical Grid: Latitude

• Definition: Latitudes measure angle north or south of the equator.

• Key reference points:

  • The equator: 0^ ext{$ op$} latitude

  • The North Pole: $90^ op$ N latitude

  • The South Pole: $90^ op$ S latitude

• Parallels: Latitudes are parallel to each other (e.g., 40th parallel is the line at $40^ op$).

Latitude Units: DMS (Degrees, Minutes, Seconds)

• Lat. is expressed as degrees, minutes, seconds:

  • $1^ op = 60'$; $1' = 60''$

• Example: Morehead, KY

  • DMS form: $38^ op 10' 40.17'' ext{ N}$

• The relationship of decomposition: $1^ op = 60' \ 1' = 60''$

Latitude Units: Decimal Degrees

• Another representation: decimal degrees (DD)

• Example: Morehead, KY

  • DD form: $38.177825^ op ext{ N}$

  • DMS form: $38^ op 10' 40.17'' ext{ N}$

Seven Important Latitudes (Impact of solar energy on climate)

• Equator: $0^ op$

• Tropic of Cancer: $23.5^ op ext{ N}$

• Tropic of Capricorn: $23.5^ op ext{ S}$

• Arctic Circle: $66.5^ op ext{ N}$

• Antarctic Circle: $66.5^ op ext{ S}$

• North Pole: $90^ op ext{ N}$

• South Pole: $90^ op ext{ S}$

• Significance: They mark zones of varying solar radiation and climate patterns.

Descriptive Zones of Latitude

• Low latitude: between the equator and ${30^ op}$ N/S

• Midlatitude: between about ${30^ op}$ and ${60^ op}$ N/S

• High latitude: greater than about ${60^ op}$ N/S

• Equatorial: within a few degrees of the equator

• Tropical: within the tropics (between $23.5^ op ext{ N}$ and $23.5^ op ext{ S}$)

• Subtropical: slightly poleward of the tropics (around $25^ op ext{ N}$ and $25^ op ext{ S}$ to $30^ op ext{ N/S}$)

• Polar: within a few degrees of the North or South Pole

The Geographic Grid: Longitudes

• Longitudes describe east–west positions; angular description

• Range: A maximum of $180^ op$ in each direction

• Meridians: imaginary lines connecting points along the same longitude

• Convergence: longitudes converge at the poles

The Prime Meridian of the World

• Established at an international conference in 1884

• Longitude zero: $0^ op 0' 0''$ at Greenwich, England (near London)

A Polar View of Meridians (Illustration context)

• Shows meridian lines radiating from the North Pole with various longitude values (e.g., $60^ op ext{E}, 30^ op ext{E}, 0^ op, 30^ op ext{W}, 60^ op ext{W}$, etc.)

Longitude Units

• Like latitude, longitude can be expressed in:

  • Degrees, minutes, seconds (DMS)

  • Decimal degrees (DD)

• Example: Morehead, KY

  • DMS: $83^ op 26' 04.39'' ext{ W}$

  • DD: $83.434553^ op ext{ W}$

How to Find Latitude and Longitude

• Steps:
  1) Start from a reference point: equator for latitude; Prime Meridian for longitude
  2) Determine direction to travel: north-south for latitude; east-west for longitude
  3) Determine distance in degrees: latitude ranges $0^ op-90^ op$; longitude $0^ op-180^ op$

• Convention: give latitude first, then longitude, e.g., $35^ op ext{ N } 75^ op ext{ E}$

Latitude and Longitude: Practical Example

• A red dot example location: $49^ op ext{ N } 60^ op ext{ E}$, a location in western Kazakhstan

• Prompted question: What about the red star (★)? (conceptual exercise to identify a different coordinate)

Summary (Key Takeaways)

• Geography is the description of the Earth from Greek roots; it studies location, distribution, and variation across space.

• Elements of Geography:

  • Physical Geography: landforms, rocks/minerals, water, weather & climate, plants

  • Human Geography: population, animals, soil, food, economic activities, languages, religions, political systems, settlements, social science

• Global Environmental Change covers natural and human-caused processes altering landscapes and the environment.

• The Four Environmental Spheres: Lithosphere, Atmosphere, Hydrosphere, Biosphere; all interact to shape the Earth’s surface.

• The Geographic Grid (Latitude and Longitude) provides precise global location via a graticule:

  • Latitude measures north-south position relative to the equator; paralleled lines; key references: $0^ op, 90^ op N, 90^ op S$

  • Longitude measures east-west position relative to the Prime Meridian; meridians converge at the poles; range up to $180^ op$ in each direction; prime meridian at Greenwich is $0^ op$.

• Latitude and longitude can be expressed in DMS or decimal degrees; conversion rules: $1^ op = 60'$ and $1' = 60''$; example conversions provided for Morehead, KY:$38^ op 10' 40.17'' ext{ N}$ or $38.177825^ op ext{ N}$.

• Key latitudinal belts and zones influence climate and environmental conditions: Equator, Tropics, Polar zones, and intermediate belts like Midlatitude and Subtropical zones, with important reference parallels at $23.5^ op$, $66.5^ op$, etc.

• The Prime Meridian and global longitude conventions enable standardized positioning and navigation.