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Tectonic - Coggle Diagram
Tectonic
Basics
-
Continents
- North America
- South America
- Africa
- Europe
- Asia
- Australia/Oceana
- Antartica
Major Plates
- Pacific
- North America
- South America
- African
- Eurasian
- Antartica
- Indian-Australian
Minor Plates
- Caribbean
- Cocos
- Nazca
- Somalian
- Philippine
- Okhotsk
- Arabian
- Sunda
-
Super Volcanoes
- VEI = 8, Logscale : each magnitude of power *10 bigger than the last one
Hazards/Risks
-
- Pressure and Release Model – Blaikie et al. (1994)
- Root cause : low access to resources, limited influence in decision making, poor governance, a weak economy
- Dynamic Pressures : low capacity : lacking education &skills, lack of investment, lack of press freedom, lack of ethical standards in public life, rapid change (population growth (quick), urbanisation, deforestation)
- Unsafe Conditions : lack of disaster prep, no warning systems, fragile economy & lack of social safety net
when added to the natural hazard, the risk is calculated
- Prediction and Forecasting
- Prediction : knowing when and where the hazard will stike in advance with time for evacuation
- Volcanoes : Predictable
- Tsunamies : once the waves have started the hit is calculated
- Earthquakes : unpredictable
- Forecasting : less precise, percentage chance of disaster based on previous data, eg. The old fault lines along Anatolia prove to have a cycle of fracturing
- Disaster Response :
- Predisaster : Prep, warn and evacuate
- Hazard Event
- Response : Saving people
- Recovery : Ongoing assistance, reconstructon, resettlement, relocation
- Mitigation : any action taken to reduce scale of the next disaster
- Disaster Modification Stragegies :
- Modify the event : prevention
- Modify the Vulnerability : prediction and forecastin, education and practice
- Modify the loss : response and recovery || Short term : medical and rescue, Long term : rehousing and rebuilding
Hazards
-
Volcanic Hazards
- Primary
- Basaltic Lava : Constructive – Slow, threat to property; Heimay || Eldfjell, 1973
- Gas : Constructive – Sulphur Dioxide, Carbon Dioxide; Laki ||1783, 25% population died
- Tephra : Destructive – Cause internal bleeding, roofs collapse; Eylafjallajökull || 2010
- Pyroclastic Flow : Destructive – Wind blows ash, hot rock and hot gas over the world; Mt. Pelee || Martinique, 1902, 30k Died
- Lateral Blast : Destructive – Side Explosion; Mt. St. Helens || 1980, spread for 18 miles
Secondary
- Mass Movements : Both – Lahar (Mudflow), water from snow/rain/rivers mixes with mud; Mt. St. Helens || 1980, 40/50 miles away from explosion
- Jokülhlaup : Both – volcanoes under glaciers erupt and cause flooding; Grimsuatun || 1996, under Vatnajokull
- Tsunamis : Both – Landslides from volcanoes can cause water displacement; Krakatau || 1883, 34k people dead
- Climate Change : Both – Tephra blocks sun, CO₂, greenhouse gases; Tambora || 1815 // Permian-Triassic Mass extinction
- Forest Fire : Both – Tephra + Lava in forest
- Thunder Storms : Both – Volcanic ash and clouds; Eyjafjallakökull || 2010
Earthquake Hazards
- Wave Types
- Primary Waves
- First
- Through all earth layers
- 8KM/s
- Not too damaging
- Back and forth motions
- Secondary Waves
- crust and mantle, not liquid
- 4.8KM/s
- Up and Down motions
- Love Waves
- Surface
- 4.3KM/s
- Most damage
- High amplitude
- Measurement of Earthquakes
- Movement Magnitude Scale (Replaced Richter Scale)
- Logscale, not damage done
- Measures energy released
- objective scale
- 1-12
- Subjective Scale
- Primary
- Ground Shakes : Buildings collapse
- Crustal Fracture : Roads are broken and railways damaged
- Secondary
- Soil Liquifaction : Buildings fall, ground is unstable, reclaimed land susceptible, breaks infastructure ∴ soil particles move apart & act like liquid
- Fire : San Francisco || 1906, Fires for a week ∴ electricity and gas issues
- Mass Movement : Crushes people, floods, blocks, water/walk ways, buries buildings ∴ mud/rock/land movements
- tsumani : drowning, flooding, destruction ∴ movemeent of sea flood cause mass water displacement
- Types
- Tectonic : Volcanoes, earthquakes, tsunami
- Hydrometeorological : Tropical Storms, flooding, storm surges, drought, tornado, hail, storm, blizzards
- Mass movement : avalanche, landslides, sinkholes, lahar (mudflow), rockfalls, slumps
- Biological : disease, wildfires, locust plagues
Plate Margin || Boundary
- Divergent
- Oceanic Contructive : Crust Created – Basaltic Lava & Non-Vicious & <55% Silica, low gas content ∴ effusive eruption
- Continental Constructive : Basaltic & Non-Vicious & <55%, low gas content ∴ effusive eruption – Shallow Focus
- Convergent
- Ocean-Ocean Destructive : subduction, conical; high gas content, ash, high silica >70% viscous ∴ explosive eruption – Deep and Shallow Focus
- Ocean-Continental : fold mountains (E.g. Andes), conical, dense ocean crust, subduction; >70% silica content, high gas content, viscous
- Collision : no volcanoes, 7-8 magnitude not common – Shallow focus
- Transform
- Conservative : offset streams, big earthquakes, no volcanoes
Examples/Depth Studies
- Examples
- Volcanoes
- Eyjafjallajökull || 2010
- Mt. St. Helen || 1980
- Earthquakes
- Haiti, Port-au-Prince || 2010
- San Francisco || 1989
-
Spearman
r = 1-(6∑d²)/(n³-n)
- Correlation Coefficient
- -1 Perfect Negative Correlation
- -0.7 Strong Neg
- -0.5 Moderate Neg
- -0.3 Weak Neg
- 0 No Correlation
- 0.3 Weak Pos
- 0.5 Moderate Pos
- 0.7 Strong Pos
- 1 Perfect Positive Correlation