Restless Earth Flashcards
What happens at constructive plate boundaries?
Rising magma splits up continental crust, forming new ocean crust.
What happens at destructive plate boundaries?
Oceanic plates collide with continental plates; and when this happens the denser basaltic oceanic crust subducts under the continental plate. As it subducts into the mantle it increases in pressure and temperature.
What happens at collision zone boundaries?
two continental plates collide, and as they are of the same density neither of them subduct, resulting in them forcing upwards to form fold mountains
What events can occur at constructive plate boundaries?
Volcanoes - as magma fills the gaps
What events can occur and destructive plate boundaries?
Volcanoes and fold mountains
What events can occur and conservative plate margins?
Earthquakes
What events can happen at collision zone margins?
Fold mountains
what is an example of a constructive plate boundary?
The mid-Atlantic ridge
What is an example of a destructive plate margin?
Where the nazca plate meets the South American plate
What is an example of a conservative plate margin?
San Andreas fault
What is an example of a collision zone plate boundary?
Indo-Australian and Eurasian plate forming the Himalayas
What happens at conservative plate boundaries ?
plates slide past each other or move on the same direction but at different speeds
1) no crust is destroyed or formed
2) great strain builds up along the junction with sudden lurches along the fault
3) earthquakes are frequent and large
What does the impact of hazards depend on?
Size of event
Vulnerability of the population
How prepared the population are
Where do earthquakes occur?
Conservative plate margins and sometimes miles away from margins
Where do volcanoes occur?
Destructive plate boundaries and sometimes on hotspots
