Restless Earth Flashcards
Name the layers of the earth starting from the middle?
Inner Core Outer Core Mantle Crust Asthenosphere
What is the core made out of?
Iron/Nickle
There are two types of crust what are they?
Oceanic Crust and Continental Crust
What are these crusts made out of?
Oceanic Crust - Basalt
Continental - Granite
Information on the thickness of the crusts?
- Continental crust is the THICKEST between 25-80km thick
- Oceanic crust is the THINNEST with millions of tonnes of seawater on top of it but this also makes it the densest plate it is between 6-8km thick
Name 4 tectonic plates?
- Eurasian plate
- North American plate
- South American plate
- Pacific plate
- Antarctic plate
- African plate
- Australian plate
- Nasca plate
What are CONVECTION CURRENTS?
Nuclear decay in the core causes heat which heats up magma. This magma rises towards the crust, while this is happening cool magma at the crust falls towards the core this causes CONVECTION CURRENTS
How do the Tectonic plates move?
The convection currents move along the crust pushing it
What are the 4 types of plate boundary?
- Collision zones
- Conservative plate boundary
- Constructive plate boundary
- Destructive plate boundry
Collision Zones
- Himalayas formed as the eurasian and indian plates PUSH into each other
- Destructive earthquakes magnitude 9.0
- Volcanoes are very rare
Conservative plate boundaries
- San andreas fault as the north american and pacific plates SLIDE past each other
- Small earthquakes every day
- Destructive earthquakes up to magnitude 8.5
- No volcanos
Constructive plate boundaries
- Iceland on the mid atlantic ridge there plates PULL apart from each other
- Eurasian and North American plates pulling apart
- Small earthquakes 5.0-6.0 magnitude
- volcanos erupt basalt lava at 1200 C
Destructive plate boundaries
- Oceanic plate ALWAYS SUBDUCTS under
- Andres mountains
- Very destructive earthquakes 9.5 can cause earthquakes
- Very explosive volcanoes steep sided erupt andesite lava 900-1000 C
Stratovolcanoes are..
- formed at destructive plate boundaries
- these volcanoes are composed of alternating layers of lava and ash other volcanoes are just lava
- andesite lava (acidic) flows a short distance and produces steep sides
Shield volcanoes
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