apes unit 6 test

PLATE TECTONICS

  • Boundaries

    • Convergent: Converge to a point, magma moves down (moving towards each other)

      • On land, forms mountain ranges like Himalayas 

      • On land moving toward ocean plate, ocean plate moves under because more density (can cause oceanic trenches)

        • Basalt makes up majority of ocean crust 

      • Has earthquakes, no volcanoes

      • Ocean-ocean, ocean-continental, continental-continental

      • Ex. Ring of Fire

    • Divergent: Moving away, magma moves up and cools

      • Forms volcanoes + new landmass with magma eruptions (i.e volcanic islands)

      • Continental-continental

      • Ex. Mid Atlantic Ridge

    • Transform: Move parallel to one another

      • Many earthquakes around this area, no volcanoes

      • Continental-continental

      • Ex. San Andreas Fault

        • Pacific Plate is sliding past the North American Plate

        • Moves every ~120 years; it's been ~160 years since it moved (so “CA is doomed”)

  • Seafloor spreading: formation of ocean crust as a result of magma pushing upward and outward from the mantle to the surface



EARTHQUAKES

  • Focus: area where energy is released (where the earthquake beings)

    • Seismic waves travel outward in all directions from the focus

  • Epicenter: directly above the focus, on Earth’s surface

  • Measured by the Richter scale 

    • 1- very weak (not felt)

    • 4- you can feel it

    • 8- collapse of buildings

    • Recorded by a seismograph

  • Waves

    • Body waves

      • P waves: travel through earth; Caused by expansion & contraction of bedrock

        • Weaker shocks compared to S waves (but moves much faster)

        • Can travel through solids and liquids

          • The more rigid the material, the faster the p wave

      • S waves: produced when material moves vertically/horizontally and travels only within the uppermost layers of the earth

        • Can only travel through solids

          • Cannot be detected on the other side of Earth because they can't travel through the liquid outer core

        • Typically causes the most destruction 

      • Lag time: differences in arrival times of P and S waves (Increases with distance from epicenter)

    • Surface waves: produce rolling / swaying motion

      • (NOT ON TEST)

      • Slower than P or S waves

      • Cause ground motion and damage

      • Occur when P and S waves transfer energy to surface

      • Rayleigh waves: ground shakes in an elliptical pattern (similar to ocean waves)

      • Love waves: horizontal; moves surface from side to side, perpendicular to p wave

      • Same frequency, > 1.0 Hz  =  Rayleigh wave is 2x as strong as love wave

      • Same frequency, < 1.0 Hz  =  Love wave is stronger than Rayleigh wave

  • Severity depends on:

    • Amount of potential energy that has been stored

    • Distance from epicenter  (closer = stronger)

    • How far below the surface the movement occurred

    • Makeup of the rock material



VOLCANOES

  • ~500 active volcanoes on Earth; at least 50 eruptions a year

  • Two types

    • Shield: Wide; lava oozes out slowly

    • Composite/Stratovolcanoes: Steeper & more violent

  • Lava: molten magma that emerges from the volcano; very slow

  • Pyroclastic flow: poisonous ash cloud that emerges during an eruption; travels over 100 mph (DEADLIER THAN LAVA)

  • Creates new land where life can flourish

  • Ring of Fire: ~90% of earthquakes; ~75% of volcanoes are located here (others are located at hotspots where the crust is thinner, ex Hawaii)

    • Boxing Day tsunami, 2004: > 250,000 people died

      • Caused by a megathrust earthquake (most powerful type)

    • Alaska, March 1964: NA’s biggest recorded earthquake

      • So powerful ground movements were observed in Florida (~4000 mi away)

    • In AK, there are ~1500 earthquakes every month

    • Earthquakes that occur in the ocean are shallower; gets deeper as you go inland

      • Creates a “dipping” feature - drops below the ground

      • Subduction: Sea floor slides under the land

      • As it moves, the top sedimentary layers are “scraped off” and pushed up (can form mountains)

      • Sea bed brings water in contact with the magma → creates magma plumes that create explosive volcanoes



TSUNAMIS

  • Tsu = harbor; nami = wave → harbor wave

  • Caused by volcanoes, landslides, or earthquakes under the ocean floor

  • Oceanic and continental plate collide → pressure builds

    • Oceanic plate (heavy) slides under the continental plate

    • Action is mirrored on the surface of the water (some water rises up while the rest goes down = wave) → Gravity pulls it back down

    • Seismic waves still travel through the water (up to 970 km/hr)

    • Extends much deeper than regular ocean waves

    • Can travel up to 16,000 km (carries a lot of water and has a lot of energy)

    • As they reach the shore, they slow down and pack together → water level rises

  • Earthquake with a magnitude > 7.5 to generate a massive tsunami

    • 2004 tsunami was caused by a 9.0 tsunami

  • Can sometimes be predictable (ex. receding waves)



ROCKS

  • Types

    • Igneous

      • Intrusive: slow magma cooling (ex. granite)

      • Extrusive: rapid lava cooling (ex. obsidian) 

        • Shiny and glasslike (no crystal formation)

        • Basalt: has gas bubbles (cools slower than obsidian)

      • Hard, no layers

    • Sedimentary

      • Classic: compacted broken rocks (ex. sandstone)

        • Conglomerate: sand and pebbles are visible

      • Chemical: compacted dissolved minerals (ex. limestone)

        • Often found near oceans and lakes (contains fossils)

      • Organic: bompacted biogenic matter (ex. coal)

      • Crumbly, layered

    • Metamorphic

      • Transformation of other rocks under intense heat and pressure

      • Relatively hard, may or may not have layers 

      • Can have crystals

      • Foliated: layered (ex. slate)

      • Non-foliated: no layers (ex. marble; comes from limestone)

  • Rock Cycle: continuous process of formation, breakdown, and reformation or rocks

    • Igneous / sedimentary rock + deformation (heat & pressure) = metamorphic rock

    • Any rock + weathering & erosion = sediments

    • Sediments + lithification (compaction & cementation) = sedimentary rock (ex. coal)

    • Metamorphic / igneous rock + melting = magma

    • Magma + crystallization (cooling) = igneous rock

  • Connections to mining

    • Mineral deposits form from igneous processes (ex. cooling of magma chambers)

    • Sedimentary layers contain coal, oil, and gas reserves

    • Metamorphic processes concentrate valuable resources (like gemstones)

  • Structure of the Earth

    • Core: innermost zone; made mostly of iron and nickel (liquid outer layer and solid inner layer)

    • Mantle: above the core; contains magma

    • Magma: molten rock

    • Asthenosphere: layer of Earth located in the outer part of the mantle; composed of semi-molten rock

    • Lithosphere: outermost layer; includes the mantle and crust

    • Crust: chemically distinct outermost layer of the lithosphere



MINING

  • Earth’s crust = 45% O, 27% Si, 8% Al

  • Terms

    • Ore: concentrated accumulations of minerals from which economically valuable materials can be extracted

    • Overburden: soil and rock that covers the ore (land that needs to be removed before excavation)

    • Metals: Elements that can conduct electricity & heat (Cu, Ni, Al, Au)

    • Reserve: Known quantity of a resource that can be recovered

    • Spoils: materials removed to extract ore (the rock that is removed to access ore)

      • Spoil banks: holes that were filled with waste (cheap & easy; susceptible to erosion, causes sediment runoff)

    • Gangue: unwanted part of the ore; left over after extracting valuable minerals (after processing)

    • Tailings: piles of gangues (after the gangue is processed and finely ground)

    • Subsidence: gradual collapse of land due to underground coal mining

    • Rare earth metals: Sc, Y, lanthanides

      • Sc: alloys with Al, used in tech, baseball bats, and military jets

      • Widely distributed throughout rocks concentrated enough to get a commercially viable deposit

  • Types

    • Surface: cheap, safe, very destructive

      • Open-pit mining: large visible pit (ex. quarries)

        • Material is removed using large equipment

        • Resource is close to surface

        • Degrades landscape, affects air and water quality

      • Strip mining: removes strips of soil and rock

        • Similar to open-pit, but not as deep

        • Remove material, extract resource, return spoils / tailings

        • Area strip mining: flat terrain (can cause erosion)

        • Contour strip mining: mountainous areas (terraces are cut into the mountain)

      • Mountaintop removal: uses explosives to expose seams of minerals

        • Tailings are deposited in nearby regions

        • Causes deforestation and carbon emissions (burning of coal)

      • Placer mining: looking for minerals / metals in river sediments

    • Subsurface: expensive, dangerous, less damage to the environment

      • Underground coal mining: open shafts into the earth that “follows” the coal

        • AMD can drain out of mines

        • The ground above each shaft could collapse 

      • Room and pillar: pillars of coal are left to support the cavern, creating “rooms” of coal (to prevent collapse)

        • Can cause water pollution and changes in groundwater flow patterns

      • Longwall mining: extracts minerals using a shearer

        • Good for ores that form horizontal deposits

      • Shaft mining: vertical tunnel straight into the deposit

        • Top of excavation is at the ground surface = shaft

        • Top of excavation is underground = winze / subshaft

      • Slope and drift mining (for coal)

        • Slope = diagonally sloping access shafts

        • Drift = Horizontal access tunnels

      • In situ: for radioactive U

      • Dredging: sand is removed from the ocean floor

        • Can be used to restore beaches

        • Destroys benthic ecosystems

      • Solution mining: pumping water into subsurface mineral deposits to bring dissolved minerals to the surface

      • Hydraulic fracturing: fracking

        • Creates fractures in rock by injecting a fluid that forces them open

        • Allows more oil and gas to flow out

      • Mine adit: entrance to an underground mine; serves as an entrance, drainage area, tunnel ventilation

  • Steps

    • Prospecting: finding places where there is ore

    • Mine exploration & development: whether the ore can be extracted economically

    • Mining: extraction of ore

    • Beneficiation: separate ore from rock

    • Smelting / refining: extract pure mineral from ore

      • Heat bleaching: takes low grade ore and extracts / concentrates the rare earth metals they contain

    • Transportation: brining mineral to market

    • Marketing & sales: finding buyers to sell the mineral

  • Impacts

    • Air: Dust particles, methane / CO2 (fossil fuels)

    • Soil: increases erosion (loss of vegetation), loss of topsoil in strip-mined regions

    • Biodiversity: habitat destruction

    • Health: Increased regulation to reduce health risks

      • Mine collapse, fire, asphyxiation, pneumoconiosis, asbestosis, silicosis, metal poisoning (especially Hg), radiation exposure

      • Black lung: comes from inhaling coal dust (type of pneumoconiosis - CWP)

    • Water: contamination as a result of tailings, accidental drainage of rivers/lakes

    • Acid Mine Drainage (AMD): formation of acidic water in heavy metals

      • Can react with water to form sulfuric acid

      • pyrite + O2 + H2O = Fe(OH)3 + SO4 + H+      (NOT ON TEST)

        • pyrite + oxygen + water = iron (iii) hydroxide + sulfate + hydrogen ions

      • Different AMD flows in different mines have different amounts of rare earth metals because different plants / sediments were compressed into the coal

      • Has a heavy rare earth metal : total metal ratio of ~50% (largest mine only has a ratio of ~12%)

      • Treatment:

        • Add lyme to AMD to form a slurry (thin mix of liquid and sludge that will flow)

        • Moves through a clarifier, where the heavier particles and sludge settle to the bottom

        • Water moves to get treated, sludge goes to geotubes

          • Massive expensive for treatment (Can’t be thrown into a landfill because it can contaminate groundwater supplies)

          • Lets the water flow out, but keeps solids in

          • One tube has ~ $11,000 of rare earth metals

  • Regulation

    • MSHA (Mine Safety and Health Administration) enforces health standards

    • Mining Law of 1872 (General Mining Act):

      • Allows individuals / companies to recover ores and fuels from federal lands

      • Few provisions for environmental protection

    • Surface Mining Control and Reclamation Act (1977)

      • Land must be minimally disturbed during coal mining, then reclaimed

      • Regulates the environmental effects of coal mining

      • Created two programs to reclaim abandoned mines and to regulate active mines

      • Related laws: 

        • Clean Air Act: regulates air emissions

        • Clean Water Act: regulates discharge of pollutants into water

        • Superfund Act: tax on chemical / petroleum industries

  • Resources

    • Metallic (ex. Au, Cu, Pd), non-metallic (ex. sand, gravel), energy resources (ex. coal, U)

    • Mineral reserve: economically mineable part of a measured mineral resource

      • Proven reserve: offers >90% probability of successful extraction

      • Probable reserve: ≥50% probability of extraction

      • Possible reserve: unproved deposits; probability of successful extraction ≥10%

    • Sustainability

      • Recycling items with important heavy metals

      • Reducing the amount of heavy metals in products (more efficient usage)

    • Economic Mineralogy

      • Minerals are important in domestic & international commerce

      • Gold, silver, diamond = jewelry, electronics, grinding 

      • Gypsum, calcite = construction

      • Copper, hematite = electronics, manufacturing

      • Clay minerals = clay industry

      • Biggest consumers: US, Japan, Europe

      • Biggest producers: South America, South Africa, Russia, CHINA

      • Blood diamonds

        • Diamonds mined in a war zone and sold to finance war efforts

        • Includes diamonds mined during civil wars in Angola, Sierra Leone, and the Ivory Coast



LITHIUM MINING



SANTA ANA WINDS

  • Formation

    • High pressure builds over the Great Basin

    • Compression and heating of air

    • Canyon & valley effects: narrow passages amplify wind speed

  • Characteristics

    • Hot and dry (relative humidity < 10%)

    • Strong and gusty (can knock down trees and power lines)

    • Prolonged (can last for several days)

  • Occurs from early fall - winter

    • Air over the inland deserts cools (denser and heavier, so it sinks)

    • High pressure systems form over deserts (pushes the air outward)

    • Pressure is higher inland and lower near the coast, so air moves from desert areas towards lower-pressure coastal areas

    • Wind compresses as it passes through mountain passes (increases heat and speed)

  • Because of these conditions, it is very easy for fires to start

    • Brings very dry air to coastal areas (dries vegetation and makes them more flammable)

      • Lower ignition temperature: requires less heat to ignite; a very small spark / ember can easily start a fire

      • As vegetation dries, it undergoes pyrolysis (organic material like cellulose breaks down into flammable gases → mixes with oxygen and ignites)

    • Strong winds can fan small sparks, creating larger fires (can also carry embers, starting spot fires)

      • Fast winds provide a continuous supply of oxygen = burns hotter and faster

    • Hot air creates warm conditions where fires spread easily

    • Compression heating (air is compressed due to increasing pressure at low altitudes) causes adiabatic heating

      • This allows the air to hold more moisture, but because there isn’t any water for it to hold, humidity drops even further

  • Impact on CA wildfires

    • Created the perfect conditions for fire spread

    • High temperatures amplified fire intensity

    • Additional dangers

      • Power outages (winds can damage power infrastructure, like power lines)

      • Increase in respiratory issues (inhalation of dust and smoke)

      • Psychological stress (from wildfire threats)

    • Reduce risks

      • Infrastructure improvements (underground power lines, fire-resistant materials)

      • Community preparedness (evacuation plans, firebreaks)

      • Early warning systems (monitoring weather patterns)

      • Satellite monitoring (for fire prediction)

robot