Tectonic Hazards Flashcards
3 main sections of the earth
crust
mantle
core
Describe the structure of the crust
10-70km thick
less than 1% of earth’s volume
made from rocks like granite and basalt
range up to 800 degrees celsius
Name 2 types of plates
Continental and Oceanic
Give the characteristics of the mantle
thickness of 2900km
800 to 3000 degrees celsius
Give the characteristics of the core
inner and outer core
contain iron and nickel mainly
range from 3000 to 5000 degrees celsius
2 causes that make tectonic plates move
convection currents
slab pull force
Plates that move away are…
divergent plates
Plates that move towards each other are…
convergent plates
What is a plate boundary?
Point where two or more plates meet
Divergent plate boundary typically form…
Rift alleys & block mountains
Ridges
Volcanoes
Convergent plates often form…
trenches
fold mountains
volcanoes
Transform plates often form…
earthquakes.
Define what a volcano is
landform formed by magma ejected from the mantle onto earth’s surface
How do earthquakes occur?
2 plates slide past each other horizontally, build up tension & pressure which results in violent earthquakes when released
Examples of continental continental plate divergence.
Between African plate Nubian and Arabian plate
Describe continental continental plate divergence
two plates forced apart from each other due to rising and diverging mantle convection currents
plates stretch and cause fractures
Landforms of continental continental plate divergence
rift valley
earthquake
block mountains
When plates diverge and fracture the crust it is also known as…
Faulting
Landforms of oceanic oceanic plate divergence
mid oceanic ridge
volcanoes
When lava cools and solidifies after flowing out onto the sea floor it is known as…
Sea floor spreading
What is rift valley?
Rift valley: valley with steep sides
What is mid oceanic ridge?
Central ridge structure that divides ocean base in half
What is block mountain?
Block mountain: block of land with steep slopes left standing higher than surrounding land
Landforms of oceanic oceanic plate convergence
Island volcano
trench