Chapter 1 - Intro to Earth

Terms

  • Geography - “Earth Description”
  • Physical Geography - characteristics of the earth (Environmental Geography)
  • Human Geography - cultural, economic, urban, etc. - the ways humans interact
  • Interrelationships - everything is connected to everything else
  • Global Environmental Change - Human and Natural processes that alter the environment in specific regions
  • Globalization - the increasing connectivity of the world as a result of human expansion. Specifically for this textbook, the consequences of globalization matter
    • i.e. Cutting down rainforests in the Amazon to clear space for farming due to an increased necessity for food as a result of increased population globally
  • Scientific Method:

  

  1. Observe a phenomenon that raises a question
  2. Generate a hypothesis to answer the question
  3. Design an experiment to test the hypothesis
  4. Predict the outcome of the experiment
  5. Conduct the experiment
  6. Draw conclusions based on the experiment
  7. Either revise the initial hypothesis are redo the experiment OR create a general rule based on your conclusions
  • Theory - a scientific fact drawn from experimentation
  • Systems of Measurement
    • Metric - grams, meters, liters, etc.
    • English Customary - pounds, feet, gallons, etc.
  • Closed Systems
    • An area/cycle that is isolated within a region
    • Very rare on Earth, technically Earth as a whole is a closed system (except for energy)
  • Open Systems
    • A cycle who’s inputs/outputs can exist outside of a region
    • A lake that receives water from rain and has water exist through a river
  • Equilibrium - where the inputs and outputs of a system/cycle are balanced
  • Positive Feedback Loops
    • A disruption to an equilibrium that reproduces the disruption
    • Global Warming: Increased warming causes ice to melt, which allows trapped methane to be released, causing increased warming
  • Negative feedback loops
    • A disruption to an equilibrium that leads back to equilibrium
    • Cloud Cover: Increased warming leads to more evaporation and cloud cover, which decreases incoming sunlight

Earth’s Environmental Spheres

Lithosphere - related to all rocks/rock cycles in Earth’s system

Hydrosphere - comprises of water in all forms (steam, oceans, rivers, ice, etc.)

Cryosphere - a subcomponent of the hydrosphere relating to all frozen water (snow and ice)

Atmosphere - the layer of gases that surrounds the planet

Biosphere - relating to all life on Earth

Some Notes:

  • Spheres are not disconnected - they interact with each other frequently, and even “isolated” phenomenon are often associated with multiple spheres.
    • A prime example is soil. Soil is technically made up of rocks, placing it in the lithosphere. However, good soil requires water to help plants grow, and often has tons of bacteria in it, placing it in both the biosphere and hydrosphere.

Earth and the Solar System

Geography is about scale - how do we measure things in comparison to each other. The Earth is about 4.5 billion years old. The universe is approximately 13.7 Billion Years old.

Fast Earth Facts:

  • Earth isn’t a sphere - it bulges slightly at the equator, and is slightly flatter at the poles
  • Earth’s maximum relief (difference between highest point and lowest point) is about 20 kilometers
    • Mariana Trench in the Pacific Ocean and Mount Everest
  • Divided into “belts”/regions based on latitude (parallel lines that run across earth)
    • Equatorial - few degrees near equator
    • Tropical - in-between the tropics (23.5 degrees N and S)
    • Subtropical - between 25 and 30 degrees
    • Polar - few degrees near the poles
    • “Low” Latitude - 0-30 Degrees
    • “Mid” Latitude - 30-60 Degrees
    • “High” Latitude - 60-90 Degrees

Great Circles are a planes that run through the center of a circular body, producing circles that produce a diameter of the sphere. The fastest route for any plane to fly is along a great circle, as it’s the most direct path.

Earth also rotates on its axis. It takes approximately 23 hours and 56 minutes for earth to rotate. In other chapters, we’ll learn about how this produces the Coriolis Effect, which creates broad wind cycles.

Latitude are lines that run from pole to pole vertically. These lines (also called meridians) help to divide the world’s time zones. Each time zone is 15 degrees wide. The prime meridian, which runs through Greenwich, Britain, serves as the universal standard time (UTC). The opposite side of the prime meridian, or 180°W/E, is the international date line.

Meridians and Parallels are measured in degrees, minutes, and seconds. 1 Degree = 60 Minutes. 1 Minute = 60 Degrees.

  • New York Exists at:
    • 40° 43' 50.1960'' N and 73° 56' 6.8712'' W
    • 40 Degrees, 43 Minutes, 50 Seconds North by 73 Degrees, 56 Minutes, and 6 Seconds West

Sun Relations

Earth technically has an elliptical orbit - it is closest to the Sun in January (Perihelion) and furthest away in June (Aphelion). This doesn’t produce seasons, though. Rather, Earth’s 23.5 degree tilt is responsible for seasons.

  • The tilt also helps us determine the tropics (23.5°N and 23.5°S) and polar circles (66.5°N and 66.5°S)

Solar Delineation is when the Sun is directly overhead. This is only possible in the tropics, due to Earth’s tilt. During the Equinoxes (Fall and Spring) the whole world gets equal hours of sunlight (12 and 12). During the ==summer solstice==, the ==Tropic of Cancer receives direct sunlight==, and the ==Arctic Circle gets 24 hours== of sunlight, while the ==Antarctic Circle gets none==. During the ^^winter solstice^^, this flips. The ^^Tropic of Capricorn receives direct sunlight^^, the ^^South Pole gets 24 hours^^ of light, and the ^^North Pole gets none^^.

Earth’s rotation creates ring of illumination - at any given moment, half the Earth is in the Sun’s light, and half is in darkness. The ring itself are areas of the Earth where the Sun seems to sit on the horizon.

Earth revolves around the sun. It takes approximately 365.25 days. This revolution produces seasons, as the amount of sunlight received by the hemisphere changes. The summer in the northern hemisphere is the winter in the southern hemisphere, and vice versa. This is because as the northern hemisphere receives more sunlight, the southern hemisphere receives less.