Flashcards in Hazardous Earth Deck (27)
What is the 4 layers of the earth?
Crust, mantle, outer core & inner core
What are the types of plate boundaries?
Divergent, convergent, collision, conservative
What is the lithosphere?
The uppermost layer of the earth. It is cool and brittle. It includes the very tip of the mantle and above this is the crust.
What is the asthenosphere?
It is part of the Earth’s mantle. It is a hot, semi molten layer that lies beneath the tectonic plates.
What is the core?
The solid centre of the earth.
What is the mantle?
The middle layer of the earth. It lies between the crust and the core and is about 2900km thick. The outer layer is the asthenosphere.
What is continental crust?
It forms the land. It is low density and made mostly of granite. It is on average 30-50 km thick.
What is the oceanic crust?
It is under the oceans. It is 6-8km thick. It is high density and basalt.
What evidence do we have that the inner earth is hot?
Hot springs, geysers and molten lava spewing from active volcanoes.
What is made when heat rises from the core?
What moves the tectonic plates?
What is the engine of the tectonic plates?
Radioactivity in the core and mantle.
What are plumes?
Parts of the convection cells where heat moved towards the surface.
What is the core made of?
Nickel and iron
What is the mantle made of?
What plate boundaries move apart?
What are examples of primary impacts?
People die, buildings destroyed, roads blocked, bridges collapse, and people trapped
What are examples of secondary impacts?
Jobs lost, economy damaged, tourists do not visit
What is a hotspot?
A small area of the earth’s crust where an unusually high heat flow is associated with volcanic activity.
What are volcanoes like at divergent boundaries?
Not very explosive or dangerous, occur in fissures, erupt basalt lava at 1200 degrees C
Are there volcanoes at conservative boundaries?
What are volcanoes like at convergent boundaries?
Steep sided cone shape, erupt andesite lava at 900-1000 degrees C, very explosive and destructive
What are the earthquakes like at conservative boundaries?
Small (up to 5-6 on Ritcher) scale), destructive with a magnitude of up to 8.5
What are the earthquakes like at divergent plate boundaries?
Small earthquakes up to a 5-6 on Ritcher scale
What are the types of volcanoes?
Composite and shield
What are the earthquakes like at convergent plate boundaries?
Very destructive (9.5 magnitude) and tsunamis can form