EARTH SUBSYSTEM

• Factors that make Earth the only living planet in the solar system:

  • Right distance to the sun
  • Presence of an atmosphere
  • Right amount of gravity
  • Presence of oxygen
  • Presence of liquid water
  • Generation of internal heat
• Earth's subsystems:

  • The Earth is a system capable of regulating its own existence
  • Atmosphere:
  • Thin gaseous layer composed of 78% nitrogen, 21% oxygen, 0.9% argon, and trace gases
  • Important for redistributing heat through atmospheric circulation and exchanging heat and moisture with the hydrosphere
  • Low and high pressure areas:
  • Warm air converges and rises to form low pressure zones, associated with increased precipitation
  • Cold air descends to form high pressure regions, which are dry
  • Hydrosphere:
  • About 70% of Earth is covered with liquid water
• • Oceanic crust: ocean floor, basalt, thinner but more dense than continental crust
  • Mantle:
  • Thickest layer, composed of molten rock (magma)
  • Core:
  • Divided into outer core (liquid iron and nickel) and inner core (solid iron and nickel)
  • Biosphere:
  • Set of all life forms on Earth, covering all ecosystems from soil to deep sea
• • Only 3% of Earth's water is fresh, with two-thirds in ice and one-third in streams, lakes, and groundwater
  • Water cycle:
  • Processes include evaporation, condensation, precipitation, transpiration, surface runoff, and infiltration
  • Important for shaping and reshaping the Earth's surface and linking the hydrosphere, atmosphere, and lithosphere
  • Lithosphere:
  • Includes rocks of the crust and mantle, metallic outer core, and solid inner core
  • Earth is made up of the crust, mantle, and core
  • Crust:
  • Continental crust: dry land, made of granite, less dense
• System interactions:

  • Hurricanes sweep across the ocean and land, damaging dwellings of people along the coast (Atmosphere, Hydrosphere, Geosphere, Biosphere)
  • Volcanoes erupt, affecting the atmosphere, biosphere, and human habitations (Geosphere, Atmosphere, Biosphere)
  • Earthquakes can damage buildings, cause fires, and trigger tsunamis (Geosphere, Biosphere, Atmosphere, Hydrosphere)
• The lithospheric plates move over hot mantle material, and their stiffness and buoyancy drive plate tectonics.
• The Earth's atmosphere is composed mainly of nitrogen (78%) and oxygen (21%), with trace amounts of other gases.
• The lithosphere consists of the Earth's crust and solid upper part of the mantle.
• As plates diverge at mid-ocean ridges, magma from below rises and cools, adding new plate material that spreads apart.
• The atmosphere has different layers, including the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
• The troposphere is the lowest layer of the atmosphere and contains most of the air we breathe.
• Greenhouse effect refers to the process by which certain atmospheric gases trap heat from the sun within the earth's atmosphere.
• Plate boundaries occur where plates meet or interact.
• The hydrosphere includes oceans, seas, rivers, lakes, glaciers, and ice caps.
• Convergent boundary: Two plates collide, resulting in volcanism and earthquakes.
• The geosphere consists of the Earth's crust, mantle, and core.
• Divergent boundary: Plates pull apart, creating new crust at mid-ocean ridges.
• Plate convergence occurs when two plates collide or slide past each other.
• Convergent boundaries are where plates meet and interact.
• Convergent boundaries are where two plates meet and interact.
• The biosphere encompasses all living organisms and their environments.
• Plate convergence occurs when two plates collide or slide past one another, resulting in various geological processes such as mountain building, volcanism, earthquakes, and subduction zones.
• Divergent boundaries occur when plates pull away from each other.
• Air density also decreases with increasing altitude because there are fewer molecules per unit volume.
• The hydrosphere includes all water on Earth, both freshwater and saltwater, found in oceans, seas, rivers, lakes, ice caps, glaciers, groundwater, soil moisture, and atmospheric water vapor.
• Atmospheric pressure decreases as altitude increases due to the weight of the air above it.
• Temperature generally decreases with increasing altitude due to less atmospheric insulation.
• Divergent boundaries occur when two plates pull away from each other.
• The greenhouse effect helps maintain a stable temperature on Earth, but excessive levels can lead to global warming and climate change.
• Convection currents are caused by differences in temperature between the core and surface of the planet.
• Transform boundary: Plates slide past one another without adding or removing material.
• Climate change refers to long-term changes in weather patterns due to natural or manmade factors.
• Tectonic plates move due to convection currents in the asthenosphere.
• Divergent boundary: Plates move apart, creating new crust and causing rifting.
• Convection currents are caused by differences in temperature between the core and mantle.
• Global warming occurs when human activities release large amounts of carbon dioxide into the atmosphere, leading to an increase in temperatures worldwide.
• Divergent boundary: Plates move away from each other, creating new ocean floor and mountain ranges.
• Transform boundary: Plates slide past one another without collision, causing earthquakes.
• Atmospheric circulation patterns include Hadley cells, Ferrel cells, and polar cells.
• Transform boundary: Plates slide past each other without collision, causing earthquakes.