PHYSICAL - Topic 1: Tectonic processes and hazards Flashcards
(23 cards)
Name the layers of the earth - inside to out
Inner core, outer core, mantle, crust
What types of crust are there?
Oceanic, continental
What is the listhosphere?
Crust and uppermost solid mantle
What are P waves
Primary seismic waves
What happens when a P wave hits materials of different densities
EITHER
A) refracts the P wave
B) cause the P wave to travel or different speeds
What do indirect signals in the P wave shadow zone suggest?
There is a solid inner core deflecting some of the waves
What are s waves?
Secondary waves
What can S waves travel through?
They can only travel through solid or semi-solid rock
What happens when S waves hit the liquid outer core?
They are refracted and reflected by the liquid outer core
What is the composition of the continental crust?
Granitic rocks, light color. The rocks contain minerals rich in silica(si) and aluminum(al). There are sedimentary rocks evident
What is the composition of the oceanic crust?
Dark colour, Basalt, tend to contain minerals rich in silica(si) and magnesium =(ma)
What was the one big piece of land called 225 mill years ago?
Pangea
What does rifting cause?
Continents to split apart and new oceans to form
Is the inner core a solid , liquid or gas?
Solid
Is the outer core a solid, liquid or gas?
Liquid
What can a conservative plate boundary also be called
divergent plate boundary
what can a destructive plate boundary also be called
convergent
What can a conservative plate boundary also be called
transform
What is a conservative / divergent plate boundary?
sliding past each other
What is a destructive/ convergent plate boundary?
Plates come together and one is subducted under the other
What is a conservative / trasform plate boundary?
Two plates pull away from each other
What happens when an oceanic plate meets a continental plate?
The oceanic plate is denser so when the plates collide, the oceanic plate is subducted (slides) under the continental plate into the mantle. Deep ocean trenches mark the place where the oceanic plate starts to sink beneath the continental. Subduction leads to fold mountains - continental plate folds and slowly rises. Friction between plates causes earthquakes in the Benioff zone
What happens when the oceanic plate meets another oceanic plate?
The denser or faster plate is subducted beneath the other and deep ocean trenches form. The subducted plate melts and rises from benioff zone to form underwater volcanoes, making low poer earthquakes
