Earth Resources Flashcards
crust
rigid, outermost layer of solid and liquid Earth resources, serves as platform for humans, protects,
plate tectonics
motion is generated by convection in the mantle, which causes plates to move, results in topographical features and weather, movements cause minerals to move around and be brought up to the surface
boundaries / faults
the edges of plates where the most motion is generated
types of actions along boundaries
- divergent: plates move away from e/o, leads to mountains
- convergent: plates collide with e/o, forms faults
- transform/lateral: plates move side by side and scrape against e/o, creates volcanic activity and earthquakes
volcanoes
pipelines that take mantle material and bring it up to the surface, molten rock found underground is magma, when emitted by a volcano, it’s lava
2 primary types of volcanoes
- shield volcano: horizontal, massive, produces gentle but broad slope, magma flows easily, taller (ex. Hawaii)
- composite volcano: steep edges, sticky lava that doesn’t flow easily, wider, more explosive due to having more gas (ex. Mt. Pinatubo)
tsunamis
occur when an earthquake happens underwater
mineral
well-defined, naturally occurring, solid, inorganic, chemical compound
rock
an assemblage of one or more minerals
3 primary types of rocks
- igneous: created by cooling magma
- sediment: created by breakdown of igneous rocks and other abiotic substances
- metamorphic: consolidation of sedimentary and igneous rocks
techniques used to identify economically viable mineral deposits
- satellite imagery: used to identify deposits by looking at wavelengths of light which respond to diff things in the surface
- geomagnetic sensors: measure changes in magnetic fields generated by rocks
mining techniques
- open pit: cone-shaped, down into crust, dynamite
- dredging: underwater, for placer deposits (like gold which accumulates at the bottom of waterbodies)
- strip: linear, used for deposits created in layers
- shaft: dug into the crust with branches
- mountain top: removing mountain peaks
mining impacts on surface
deforestation, habitat fragmentation, soil erosion
mining impacts on atmosphere
dust and carbon emissions, transforming into other pollutants, deposited, accumulation, c.c.
underground mining impacts
collapsing the mine, sinkholes, pumping of groundwater which lowers water table
gangue
the valueless component of ore that is removed and discarded
coal
mostly C, contains H, S, and O impurities, originates from peat (decomposed materials of living things in the ground)
formation of coal
peat is compressed by heat and pressure and starts to transform into lignite and then coal, process takes a long time, quality has degraded due to more impurities
different qualities of coal that depends on carbon content
- anthracite: most carbon-rich, contains most energy per unit
- bituminous: lower carbon content, more common, contains gases that can lead to explosions when released
- lignite: low carbon content, high sulfur and metal content,
impacts of coal mining and energy use
- coal mining is expansive and intrusive
- creates atmospheric pollution
- disturbance and destruction of habitats
- acid mine drainage
- abandoned mines and decommissioning
- tailing/spoiling landslides
- energy source depletion
- damage to natural env
methods to “clean” coal
- scrubbers: decrease emissions by introducing a chemical reaction that changes sulfur into gypsum which contains less sulfur, leads to cleaner plant exhaust, turns carbon released into solid carbon which can be stored in the ground
- fluidized-bed combustion: increases efficiency by mixing coal with limestone to limit pollution and create more heat
- sequester carbon in storage: lowers net energy, energy intensive
oil/tar
the most used fuel in the world, has been used in a variety of ways,
formation of oil
petroleum is created by decomposed marine life, dead algae mixes with inorganic clays near ocean bottoms in a low-oxygen env which generates kerogen, when heated, it releases oil and gas into the sediment around it
crude oil
raw material that is extracted out of the ground
oil / tar sands
considered unconventional oil sources since it has combination of bitumen (thick, low-grade, crude oil), sand, and water, associated with heavy env degradation
oil transport
substantial risk of env damage, pipelines are the most common way of transport, other methods include marine transport and direct extraction
diversity of oil
comes from refining, heating the oil to vapourize and separate its components via distillation
plastics
created by cracking ethane and propane with heat, turns them into ethylene and propylene, can be converted into polymers, durable, lightweight, decompose after a long time, generate a lot of pollution
natural gas
volatile component that evaporates and remains trapped near its source, commonly accompanies coal and oil, the cleanest of the fossil fuels
methane flaring
natural gas is emitted into the atmosphere thru this process, this wastes and loses energy since it’s expensive and intensive to capture and transport natural gas
methane clathrates
mixture of methane and water which forms a solid ice-like structure, exist below the oceans, in permafrost, and outerspace, if it melts, methane is liberated into the atmosphere
2 types of nuclear energy
- nuclear fission: energy comes from splitting atoms
- nuclear fusion: takes energy from the initial nuclear fission reaction to make another reaction to emit more energy, would be a self-maintaining system, development may lead to an unlimited supply of electricity
uranium
non-renewable resource that doesn’t emit CO2 during energy production, radioactive, produces way more energy than fossil fuels when burned
nuclear fission
bombarding the uranium with neutrons causes a chain reaction and splits uranium,
uranium mining
can be open pit or underground, extensive processing concentrates uranium into yellowcake (intermediate form of U concentrate and is enriched to form low-grade, highly-enriched, U)
uranium processing
using gaseous diffusion, U is separated, converted into a solid, and pressed into pellets, pellets are installed into fuel rods that are placed into a reactor,
fuel is used to vapourize the water, steam moves turbines, generates electricity, and steam is condensed
uranium enrichment
takes low-grade U and concentrates its atoms to reach 4%, which is the min needed to sustain a controllable chain reaction
“spent” fuel rods
filled with a large amount of dangerous radioactive material, placed in a water tank to cool down and decay to safer levels to ensure safe handling and storage
major nuclear disasters
- Three Mile Island (USA): gas leak
- Chernobyl: released explosion, meltdown
- Fukushima: earthquake and tsunami flooded reactor, meltdown
nuclear energy and waste production
spent fuel rods are dangerous, no safe places to store radioactive materials, waste is generated at each step of mining, processing, and generation, not that efficient overall
