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)