GLOBAL GEO: THE PLANET EARTH

4 conditions for life on earth

1. stable temperature range

2. importance of water

3. importance of gases

4. role of the atmosphere

stable temperature range

• -50 to about +50 degrees C has to remain

greenhouse effect

• it allows heat in the atmosphere (carbon and water vapor)

• a natural process where certain gases in the Earth's atmosphere trap heat from the sun, warming the planet to a livable temperature

• limits the albedo effect

• plants play a significant role in creating a stable temperature through releasing water vapor and oxygen by the processes of photosynthesis and transpiration

albedo effect

• also known as “reflectivity” effect

• white or light surfaces reflect light, while black or dark surfaces absorb light

importance of water

• oceans trap heat and distribute it around the world

• the movement of heat controls weather patterns and climate

• water circulates through soil to provide nutrients to plants and other organisms

• water is also the metabolizing agent that allows plants and animals to dissolve minerals and nutrients to create energy

importance of gases

• the earth has to have 78% nitrogen, 21% oxygen, and 0.3% carbon dioxide

• essential for maintaining life on earth

• the production of carbohydrates, fats, and proteins require oxygen, carbon, and nitrogen atoms from the atmosphere, and hydrogen from water

• plants absorb carbon dioxide and produce oxygen

role of the atmosphere

• protects earth through a gaseous layer

• helps maintain a consistent temperature

• shields earth from collisions with harmful cosmic particles

• filters out excessive UV radiation

• source of all weather patterns

4 spheres 

1. lithosphere

2. atmosphere

3. hydrosphere

4. biosphere

lithosphere

• earth’s crust and all material soil, rocks, and minerals

• made up of the earth’s crust and solid upper mantle

• broken up into tectonic plates, which through their movement shape the earth’s surface

• volcanoes are often found along the plate boundaries and the occurrences of earthquakes

• weathering and erosion tear down earth’s surface

continental drift theory

• this is the scientific hypothesis that earth’s continents have moved over geological time relative to each other

• it explains the movement of continents

alfred wegener

• he noticed that continents fit together like puzzle pieces, like they had been connected at some point 

• he theorized that the continents used to be one large supercontinent (pangea)

new pangea

• pangea ultima, neopangea, pangea II

• NASA predicts that the earth will become a supercontinent in the future

plate boundaries

• plates move due to heat and gravity

1. divergent 

2. convergent

3. transform

divergent boundaries

• diverges and split

• creates a new crust

• PROCESS:

  1. Tensional forces pull plates apart.

  2. Magma rises from the mantle, creating a new crust.

  3. Formation of mid-ocean ridges and rift valleys. 

  4. Earthquakes due to crustal stretching.

transform boundaries

• slide past each other horizontally, causing earthquakes 

• PROCESS:

  1. Shear forces cause plates to move laterally.

  2. Plates grind against each other.

  3. Formation of strike-slip faults.

  4. Little to no volcanic activity.

convergent boundaries

• converges and joins together

• PROCESS:

  1. Compression forces push plates together.

  2. Subduction of denser oceanic plates.

  3. Formation of deep ocean trenches.

  4. Earthquakes along subduction zones.

effects of plate tectonic movement

• mountains form

• seafloor spreading and rift valleys

• earthquakes and tsunamis

• volcanoes

rock cycle

• the continuous process by which rocks change from one type to another over time

  From Rock Type	To Rock Type	Process
  Igneous, Sedimentary, or Metamorphic	Sedimentary	Weathering & Erosion (breaking down), followed by Lithification (compacting and cementing).
  Igneous, Sedimentary, or Metamorphic	Metamorphic	Intense Heat and Pressure deep underground.
  Igneous, Sedimentary, or Metamorphic	Igneous	Melting to form magma, followed by Cooling and Crystallization.

sedimentary rocks

• are formed from particles of sand, shells, pebbles, and other fragments of material. together, these particles gradually pile up and over time, these particles turn into rock. 

metamorphic rocks

• are formed under surface of the earth from the metamorphosis that happens because of intense heat and pressure

igneous rocks

• are formed when magma cools and hardens 

layers of the atmosphere

1. troposphere (closest)

2. stratosphere

3. mesosphere

4. thermosphere

5. exosphere (farthest)

troposphere

• closest

• weather occurs here

• temperature decreases with altitude

stratosphere 

• contains the ozone layer

• temperature becomes warmer (increases) with altitude because of the ozone layer 

mesosphere

• coldest layer (up to -120° F)

• meteors burn here 

thermosphere

• auroras occur here

• temperatures can reach 3600° F because of solar radiation 

exosphere

• outermost layer

• satellites orbit here

• particles rarely collide

mountain building

• occurs when two land plates (continental plates) slowly push into one another, they often fold upwards, creating mountain chains

seafloor spreading and rift valleys

• some tectonic plates move apart

• plates open, lava comes out, and forms land or a ridge of mountains in the middle of the Atlantic ocean

• in other areas, the separation of tectonic plates has created rift valleys—long valleys between parallel ridges of mountains

earthquake and tsunamis

• plate movements can cause a break in earth’s crust, known as a fault

• plate movements can also cause vibrations known as earthquakes

• as the plates move, they cause stress at plate boundaries

• when an earthquake occurs under or near the ocean, it creates immense ocean waves of destructive force known as tsunamis

volcanoes

• when tectonic plates diverge or go under another, pressure in the mantle is reduced and some of the hot, solid rock turns into liquid

• pockets of molten rock form beneath the surface

• magma, ashes, and gases erupt and form a volcano

• lave is when the magma reaches the surface 

ring of fire

• around the pacific ocean

• a zone of volcanoes and frequent earthquakes 

• coincides with the boundaries of the tectonic plates

weathering

• wearing down of rocks at the surface by the actions of wind, water, ice, and living things

• since water expands when it freezes, when water seeps into cracks and freezes, a crack is formed

• running water and rain may break down smaller particles

• chemicals (acids) dissolve rocks

• microorganisms also break down and disintegrates rocks

erosion

• processes by which rock, sand, and soil are broken down and carried away

• displacement of solids

deposition

• the same forces that erode one place can deposit particles and sediments in another, building it up

• areas being flooded a lot gets lots of sediments

convection

• the spread of heat through the movement of a fluid substance

• inside the mantle, semi-solid rocks are heated

• when heated, it becomes less dense and rises up 

• once it is cooled, it then goes back down

• this cycle repeats, which creates a circular motion or current

• the circular motion pushes the plates above

gravity

• also contributes to plate movement

• when oceanic and land plates collide, the dense oceanic plate is pulled by gravity under the lighter land plate

• at one end of the oceanic plate sinks, it pulls on the rest of the plate as well

how the atmosphere works

• the atmosphere moves due to uneven heating from the sun, creating convection currents

• warm air rises at the equator and cool air sinks at the poles, forming convection cells

• the rotation of earth causes the Coriolis effect, deflecting winds, and high-speed jet streams flow in the upper atmosphere, influencing air movement

convection cells

• circular patterns of air movement driven by temperature differences

• hot air rises from the equator to the poles and cool air go from the poles to the equator, which chapes wind patterns and weather systems

3 main convection cells in each hemisphere

• hadley cell

• ferrel cell

• polar cell

hadley cell

• near the equator

ferrel cell

• middle latitudes

polar cell

• near the poles

coriolis effect

• the earth’s rotation causes the deflection of moving air and water

• influences the direction of ocean currents and winds, shaping global weather patterns

• northern hemisphere: winds are deflected to the right

• southern hemisphere: winds are deflected to the left

hydrosphere

• includes all water on earth, including oceans, rivers, lakes, glaciers, and groundwater

types of freshwater

• rivers

• streams

• lakes

• aquifer

• wetlands

• swamps

• bogs

• groundwater

• glaciers

types of non-freshwater

• oceans

• icebergs

• permafrost

glaciers vs icebergs

• glaciers move along land while icebergs move along water

ocean currents

• the continuous movement of seawater that helps regulate global temperatures

• surface currents are caused by wind and earth’s rotation

• deep ocean currents are driven by differences in salinity/density and temperature

tides

• the rise and fall of sea levels caused by the gravitational pull of the moon

• spring tides: when earth, moon, and sun are aligned—higher high tides and lower low tides

• neap tides: when moon and sun are at right angles to earth—lower high tides and higher low tides

interaction between atmosphere and hydrosphere

• winds from the atmosphere drive ocean currents, which in turn affect climate

weather

• short-term and localized

• can change withing minutes or hours

• condition of the atmosphere at a specific tie and place, including temperature, humidity, precipitation, and wind

climate

• long-term and regional

• average weather over many years in one specific place

• the long-term average of weather patterns in a region, measured over 30 years or more

6 factors that influence climate

1. latitude

2. ocean currents

3. wind and air masses

4. elevation

5. relief

6. nearness to water

latitude

• the closer a region is to the equator, the warmer its climate

ocean currents

• warm ocean currents raise temperatures; cold currents lower them

wind and air masses

• winds and air masses move warm or cold air, influencing regional temperature

elevation

• higher altitudes are cooler than lower areas

relief

• mountains can block air flow, creating wet areas on the windward (direction from which the wind is blowing—upward) side and dry areas (leeward side) on opposite sides

nearness to water

• coastal areas have more moderate temperatures due to water’s heat capacity

weather and climate are influenced by factors such as

• latitude, ocean currents, elevation, relief, nearness to water, and winds

• these factors help explain differences in temperature, precipitation, and overall climate

ecosystem

• a community of living things that interact with one another and the physical world

• all work together as a functional unit

• cannot accommodate more organisms if it passes the food, water, and shelter they have in capacity

biotic

• living or once living organisms

• found in the biosphere 

• capable of reproducing

• plants (producer), animals (consumers), and microorganisms (decomposers)

abiotic

• non-living physical and chemical elements in the ecosystems

• usually located in the lithosphere, atmosphere, and hydrosphere

• physical: energy, climate, raw materials and living space (air, water, soil, sunlight)

• chemical: sources of essential nutrients (organic and inorganic substances)

function of an ecosystem

• to allow flow of energy and nutrient cycling

types of ecosystems

1. natural - terrestrial (taiga, tundra, grassland, desert, tropical rainforest, temperate deciduous forest)

2. natural - aquatic (marine: lagoons, coral reefs, mangrove | freshwater: stream, spring, wetland)

3. artificial or man-made (garden, dam, terrarium, aquarium, greenhouse)

4 laws of ecology

• created by physicist and ecologist Barry Commoner

1. law 1 - everything is connected to everything else

2. law 2 - everything must go somewhere

3. law 3 - nature knows best

4. law 4 - there is no such thing as a free lunch 

law 1

• every species is connected some ay or another (interconnected)

• every ecosystem stabilizes itself by passing through a series of cycles

law 2

• matter is indestructible

• evolution

• it doesn’t disappear, it just becomes another type of matter

law 3

• connected to the gaia theory

• human change forced into an ecosystem is bound to be detrimental

• don’t try and take matters into hands because you did not make it and you will only make it worse

• “nature is like the watchmaker and nature has refined its various ecosystems through millions of years of evolution”

law 4

• pay a price for everything we take on earth

• face the consequences of your choices

• everything you do must have a reason

• you have to do something in order to get something in return

natural hazard

• a natural event or condition that has the potential to cause harm

• keyword: potential

disaster

• when a natural hazard actually causes harm

• keyword: actually causes

types of hazards/disaster

1. atmospheric

2. geologic

3. biological

4. human-made

atmospheric

• caused by weather and climate events

geologic

• caused by processes within the earth’s crust and surface

• can be sudden or slow

biological

• related to living organisms, diseases, and environmental factors that effect human health

human-made

• caused directly by human actions

biodiversity

• “bio” means life; “diversity” means variety

• variety of life and the essential interdependence of all living things

• has intrinsic value (something that has value in and of itself | provides people; all serve a purpose)

importance of biodiversity

1. protects the atmosphere

2. agricultural production

3. stable ecosystems

protects the atmosphere

• having a variety of plants allows us to maintain the atmosphere

• greenhouse effect and amount of CO2 and O2 in the atmosphere are regulated by the diversity plants

agricultural production

• need food to survive along with various species on earth

• need the many different species of insects and birds to pollinate crops

stable ecosystems

• life processes on earth are intricately connected

• damage to one could mean damage to another

• some species are codependent on each other

what do we get from biodiversity?

• oxygen

• food

• clean water

• medicine

• aesthetics

• ideas

what actions to make to help biodiversity?

• support reforestation projects and habitat protection projects

• “leave” your leaves and leave your weeds to decompose and give nutrients

• turn your lawn into a garden

threats to biodiversity

1. habitat alteration/destruction

2. pollution

3. exploitation/overuse of land

4. global climate change

5. new species introduction/invasive species

habitat alteration/destruction

• a change in land use or land cover that has an impact on local and global ecosystems

pollution

• any matter or energy released into the environment that causes undesirable impacts on the health and well-being of humans or other organisms

• happens when humans produce materials or product in large amounts that harm living things and the earth’s natural systems

exploitation/overuse of land

• refers to harvesting a renewable resource to the point of diminishing returns or overhunting

global climate change

• human induced

invasive species

• species that enter new ecosystems and multiply, harming native species and their habitats

• often done accidentally or deliberately introduced by humans

how have humans affected biodiversity?

• disrupted food chains, carbon cycle, water cycle; basically disrupting the cycles on earth

• through mining, deforestation, pollution, urbanization, crop selection/monoculture (one crop only; no diversity = bad)

habitat alteration/destruction

• species need their own habitat, destruction of that habitat leads to loss of species

• examples: clearing forests, hydroelectric dams, habitat fragmentation, urbanization and suburban sprawl

deforestation

• the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use

• example: conversion of forestland to farms, ranches, or urban use

desertification 

• the process by which a productive dry land area is degraded to the point that it becomes an unproductive desert land

• loses its ability to grow and cultivate

• caused by human activities: over-cultivation, overgrazing, deforestation, inappropriate irrigation techniques 

exploitation/overuse

• significant cause of extinction

• example: overhunting, poaching, urban growth

threatened

• population is low but extinction less imminent

endangered

• population is low but extinction is imminent

• good chance of becoming extinct

global climate change

• natural process; however its sped up due to human actions

• increased CO2, deforestation, and current agricultural practices has contributed in an increase of greenhouse gases

invasive species

• bringing back new species may actually causes harm

• introducing new species to an area often have disastrous effects