Question | Answer |
What are the layers of the Earth? Give a brief description of their properties. | Crust-a hard, thin outer shell that floats on the mantle.
Mantle- soft molten rock about 3800 degrees Celsius
Outer Core- liquid iron and nickel
Inner Core- Solid iron and nickel, up to 5500 degrees Celsius |
Describe a property of the crust in the Earth's structure. | The crust is broken up into large pieces like a jigsaw known as Tectonic Plates, these float on the mantle. |
What are the two types of crust. | Oceanic Crust- is what you get under oceans.
Continental Crust- is what you get under the continents or land masses. |
Describe the main properties of Oceanic Crust. | -5 to 10 km thick, dense (basalt)
-Sinks into the mantle when oceanic and continental crust meet
-The oldest is only about 180 million years old
-This crust forms constantly at constructive plate margins
-Destroyed at destructive plate margins |
Describe the main properties of Continental Crust. | -25-100 km thick, less dense (granite)
-Doesn't sink
-Very old, 3.4 billion years
-New crust is not formed
-Cannot be destroyed |
What are Tectonic Plates? | Tectonic Plates are continental sized slabs of the Earth's crust which floats on the mantle, connecting a global sized jigsaw puzzle. |
What is found on the edge of Tectonic Plates? | The Earth's crust is particularly unstable at the plate margins, this is where volcanoes are found and where Earthquakes may occur. |
What are the 7 major tectonic plates of the Earth? | -African Plate
-Antarctic Plate
-Eurasian Plate
- Indo Australian Plate
-North American Plate
-Pacific plate
-South American Plate |
How do Tectonic Plates Move? | As heat rises from the Earth's core, it sets off convection currents in the mantle. The convection currents move at about the speed that fingernails grow at.This force and power sets off Earthquakes and Volcanic Eruptions. |