L2 Restless Earth Flashcards
What are the Earth’s 4 concentric layers?
Inner core, Outer core, Mantle, Crust
What is the Earth’s crust broken up into?
Tectonic plates
What are convection currents in the Mantle caused by?
Heat rising and falling generated by radioactive decay in the core, which causes the plates to move
What happens at a Destructive plate boundary?
The two plates collide and one plate flows beneath the other- subduction. Earthquakes and volcanoes occur here.
What happens at a Constructive plate boundary?
Rising convection currents pull the crust apart forming a volcanic ridge
What happens at a Conservative plate boundary?
Two plates slide past each other. Earthquakes occur here.
What happens during a collision?
Two continental plates collide and the two plates buckle. Many Earthquakes occur here.
What are the characteristics of a Shield Volcano?
- Found on Constructive plate boundaries
- Formed by eruptions of thin, runny lava which flows a long way before it solidifies
- Have gentle sloping sides and a wide base
What are the characteristics of a Composite Volcano?
- Found on Destructive plate boundaries
- Formed by eruptions of viscous, sticky lava and ash that don’t flow far
- Have steep sloping sides and a narrow base
What are the 2 scales used to measure the magnitude of an Earthquake?
The Richter scale, The Mercalli scale
What happened in the Kashmir Earthquake in 2005?
- 75,000 dead
- 75,000 injured
- 2.8 million homeless
- Property damaged ($440 million)
What are the signs of a Volcano nearing eruption?
- Animals and birds moving out from an area
- An increase in gas emissions
- An increase in soil temperature
- The Volcano swelling
Give an example of a Conservative plate margin
Pacific plate (oceanic) North American (continental)
Give an example of a Constructive plate margin
North American
Eurasian plates
Give an example of a Destructive plate margin
Nazca (oceanic) South American (continental)
