Plate tectonics GW1 Flashcards
Plate tectonics GW1
What is a natural hazard?
A natural hazard is a natural event that threatens human lives and causes damage to property.
Plate tectonics GW1
What are the 2 types of natural hazards and definitions
- Tectonic hazards, movement of continental and oceanic plate (tectonic process), occur along coastlines of Pacific Ocean eg earthquakes, volcanic eruptions
- Climate-related hazards, extreme weather and climate conditions (climate-related processes) eg storms, floods, droughts
Plate tectonics GW1
Impact of natural hazard
small scale
large scale
Plate tectonics GW1 Internal structure of core? (3) 1. ? - layer - temp - material - thickness - state
- Core
- between 3000°C and 5000°C
- mainly out of nickel –> good heat conductivity
- total: 3500km
- inner: 1400km, solid
- outer: 2100km, liquid
Plate tectonics GW1 Internal structure of core? (3) 2. ? - layer - temp - material - thickness - state
- Mantle
- upper and lower mantle
- between 800 and 3000
- solid rock
- 2900km
- rocks in lithosphere melt, molten rock – magma
Plate tectonics GW1 Internal structure of core? (3) 3. ? - layer - temp - material - thickness - state
- Crust
- basalt and granite
- continental: 35-70km
- oceanic: 5-10km
What is a tectonic plate?
- diff between oceanic and continental crust
- can be oceanic, contiental or combination
oceanic crust: - beneath deep oceans
- between 5 and 8km
- basalt, young rocks, less than 200 million year old
continental crust:
- beneath earth’s continent, shallow seas
- between 35 and 70 km
- granite, light rocks
- 4 billion years old
Why do plate tectonic plates move?
convection currents and slab-pull force
- Convection currents are movement of heat within mantle, heated by core, expand, rises and spread out beneath plates (diverge)
- causing plates, dragged along and to move away from each other
- mantle cools, sinks pulling plates along. Slab-pull force, dense, sinking oceanic plate pulls rest of plate (converge)
What are the different types of plate boundaries?
names (9)
types (3)
Name
- North American Plate
- South American Plate
- Eurasian Plate
- Indian Plate
- African Plate
- Nazca Plate
- Pacific Plate
- Philippine Plate
- Australian Plate
Type
- Divergent - move away
- Convergent - move towards
- Transform - move past
Divergent plate?
- move away, magma rise, cools, new crust
o-o c-c
Divergent 2 boundaries 1. ? - type of boundary - landform - specific example
- Oceanic-oceanic divergence
- tensional forces cause fractures
- magma rise, lave flows out, cools, new sea floor – sea-floor spreading
- formation of mid-oceanic ridge
- undersea volcanoes, grow above sea level – volcanic islands
Eg Mid-Atlantic Ridge, oceanic North American plate and oceanic Eurasian plate
volcanic islands - iceland
Divergent 2 boundaries 2. ? - type of boundary - landform - specific example
- Continental-continental divergence
- tensional forces
- rock layers, parallel forces, subside, form linear depression–rift valley and adjacent higher elevation–block mountains
Eg East African Rift Valley – Nubian boundary of African plate diverged from Somalian boundary of African Plate
Convergent plate?
- move toward, folded, subducted
Convergent 3 boundaries 1. ? - type of boundary - landform - specific example
- Oceanic-oceanic convergence
Oceanic-oceanic divergence
landform?
mid-oceanic ridge
volcanic islands
