The structure of the earth

Pregunta	Respuesta
What is the outer layer of the earth called?	Lithosphere
Draw the structure of the earth.	Image: 558822-50521-49 (image/jpg)
Lithosphere is made up of ...	...Tectonic plates
How do we know what is beneath the crust?	Seismic waves and man-made explosions.
What does the mantle lie between?	Core and the crust.
The earths core transfers energy so...	...the temperature increases with depth.
Convection currents...	...slowly move plates.
Describe subduction.	Image: recycle.gif (image/gif)
Why is the theory of plate tectonics now widely accepted my scientists?	It explains a wide range of evidence and it has been discussed and tested by many scientists.
Who's theory was not accepted?	Wegner's continental drift theory in 1914
How did it slowly become accepted?	Sea floor spreading evidence in the 1960's.
Why does magma rise up?	It is less dense than the crust. It causes volcanoes.
Magma can have different...	...compositions....eruptions.
Why do geologists study volcanoes?	To predict eruptions in the future.
How are different types of igneous rock formed?	Lava
What does runny lava produce?	Iron-rich basalt rock. (slower eruptions)
What does thick lava produce?	Silica-rich rhyolite rock. (explosive eruptions)

Resumen del Recurso

	Creado por mmit hace casi 11 años