Human Demography

• Tectonic plates:

  • Major tectonic plates include African, Antarctic, Indo Australian, North America, Pacific (largest tectonic plate), South America, Eurasian
  • Minor tectonic plates include Arabian, Caribbean, Cocos, Juan de Fuco, Indian, Nazca, Philippine Sea
• Divergent boundary:

  • Landform created at divergent boundary is a ridge
• Transformative Boundary:
• Convergent Boundary (Destructive boundary):

  • Landform created on convergent boundaries is a trench
• Plate Movements:

  • Constructive/divergent boundary type moves away from each other, with volcanoes and weak earthquakes
  • Destructive/Convergent (with one continental plate and one oceanic plate) moves towards each other, with subduction, volcanoes, and earthquakes
  • Destructive/convergent (with two continental plates, AKA collision) moves towards each other creating fold mountains, with earthquakes
  • Conservative/transform boundary moves side-by-side in opposite directions or the same direction, with earthquakes
• Stratovolcanos are found on convergent boundaries
• Subduction is the action or process in plate tectonics where one crustal plate descends below another
• Pyroclastic flow:

  • Extremely hot flow burning anything in its path, forms when lava, ash, and gases lose upward momentum and fall back to the ground
• Shield Volcanos:

  • Found on divergent boundaries, have less violent eruptions and runny lava
• Hot Spot:

  • Area over a mantle plume with hotter magma than surrounding areas
• Earthquakes:

  • Tectonic earthquakes are produced by sudden movement along faults and plate boundaries
  • Volcanic earthquakes are induced by rising lava or magma beneath active volcanoes
• Ways to limit earthquake damages:

  • Be educated on what to do during earthquakes
  • Design appropriate buildings with central columns, stabilizers, and proper foundations
• Turkey earthquake:

  • Experienced a 7.8 magnitude quake followed by aftershocks
  • Situated between the Anatolia plate and micro plate, tectonically active and unstable
• Benefits of Volcanoes:

  • Tourism benefits from over 1,500 active volcanoes worldwide
  • Fertile soil benefits from lava containing nutrients like potassium, phosphorus, and iron
  • Land formation benefits creating mountains, islands, and seafloors
  • Geothermal energy benefits from heat beneath the Earth's surface
  • Raw materials benefits from minerals brought to the surface like sulfur, gold, aluminum, copper, and diamonds
• Rivers:

  • Water cycle includes evaporation, evapotranspiration, condensation, precipitation, interception, infiltration, percolation, overland, through, and ground flow
  • Erosion types include hydraulic action, abrasion, attrition, solution, vertical erosion, lateral erosion
  • Transportation types include solution load, suspension load, saltation load, traction load
  • Deposition occurs when a river's energy decreases
• River Long Profile:

  • Source Zone in the Upper Course
  • Transition Zone in the Middle Course
  • Floodplain Zone in the Lower Course
• River deposits materials, such as huge rocks, when its energy decreases
• River Long Profile:

  • Source Zone → Upper Course
  • Transition Zone → Middle Course
  • Floodplain Zone → Lower Course
• Upper Course:

  • Source: Where the water is coming out
  • Interlocking Spurs: River bends around hard rock, creating interlocking spurs
  • V-shaped Valleys: River cuts and curves meandering
• Gorge: a narrow valley with steep, rocky walls located between hills or mountains

  • Waterfall: a river's steep fall over a rocky ledge into a plunge pool below
  • Potholes: circular holes formed in the rocky bed of a river by the grinding action of stones or gravel whirled around by the water
• Middle Course:

  • Meanders: water flows in a curvy, bendy path
  • Oxbow Lake: remains of a bend in the river, usually dries out eventually
• Lower Course:

  • Distributaries: river splits into smaller rivers at the mouth
  • Flood Plain: a flood-created flat plain with fertile soil near the river
  • Alluvium: minerals deposited on land after a flood
  • Levèes: walls built to stop a river from overflowing
• • Causes of the flood: torrential summer monsoon rains, melting snow and glaciers, global warming, building levees causing river channel to silt up, deforestation causing erosion and sediment transport, lack of flood policy and effective laws
  • Damage of flood: 9,300 dead, 14M displaced homes, infrastructure damage, loss of school buildings, livestock, malnutrition, lack of clean water
  • Responses to flood: short-term and long-term responses, government aid, foreign aid
• Case study for floods:

  • Opportunities: water supply, irrigation, agriculture, hydroelectricity, flat land for building, fertile soil, fishing, industries in Pakistan
  • Hazards: not safe to live near flood areas, deforestation affecting vegetation and wildlife, Indus river shifting course, sediment clogging irrigation canals, extreme heat causing land to be useless for cultivation, climate change increasing flooding, pressure on food and water
• Coastal Areas:

  • Fetch: distance a wave covers
  • Backwash: water retreats
  • Swash: waves cover the beach
  • Constructive waves: add material to a beach
  • Destructive wave: take material away from the beach
  • Frequency of the wave: how many waves per minute
  • Discordant coastline: different rocks meet the coast at right angles
  • Concordant coastline: different rocks are parallel to the coastline
• How do tropical storms form?

  • Found between the tropics and equator with warm water
  • Water evaporates, fueling the storm
  • Warm winds cause more evaporation
  • Moist air goes up, cools, condenses into stormy clouds
  • Circular winds form, storm begins
  • Storm surge: type of tide
• Case study for hazards:

  • Happisburgh: settlement on the Norfolk coast, eastern England
  • Coast eroding fast due to cliffs composed of silt, clay, and sand
  • Erosion rate in Happisburgh: 0.2 squared kilometers
  • Past prevention efforts: groynes, sea defenses, rock armour
  • Current prevention efforts: sandscaping, managed realignment
• Weather and Climate:

  • Weather instruments:
  • Rain gauge: measures amount of rainfall in millimeters
  • Wind vane: measures wind direction in cardinal directions
  • Anemometer: shows wind speed in miles per hour or kilometers per hour
  • Sunshine recorder: records sunshine hours
  • Stevenson screen
  • Barometer: measures atmospheric pressure in bars
  • Hygrometer: measures humidity in milliliters per cubic centimeter