What are the two main types of evidence that geologist have used to learn about Earth's interior?
direct evidence and indirect evidence
100
Describe Earth's inner core.
A dense ball of solid metal.
100
Why did geologists reject Alfred Wegener's theory?
Most geologist rejected Alfred Wegener's theory because he could not provide a satisfactory explaination for the forece that pushes or pulls the continents.
He could not identify the cause of continental drift.
100
What does subduction mean?
the process by which ocean floor sinks beneath a deep-ocean trench and back into the mantle.
100
How did scientists map the mid-ocean ridges?
using sonar
200
Give on example of direct evidence
Rock samples
200
What causes convection currents?
heating and cooling of fluid, chaning in a fluid's density, and force of gravity.
Heat from the core and the mantle itself cause convection currents in the mantle.
200
What do most geologists think the movement of Earth's plates is caused by?
convection currents in the mantle.
200
A place where two palces come together is called...
A convergent boundary
300
How do geologist obtain indirect evidence?
Recording seismic waves and studing how they travel through Earth.
300
What was Alfred Wegener's theory of continental drift?
That all continents were once joined together in a single landmass and have since drifted apart.
300
State the theory of plate tectonics.
pieces of Earth's lithosphere are in slow, constant motions, driven by convection currents in the mantle.
300
A place where two plates slip past each other, moving in opposite directions is called...
a transform boundary
400
What are the 4 layes of the Earth in order from the surface inward?
Crust, Mantle, outer core, inner core
400
What is Pangaea?
Pangaea is a super continent that formed from when the continents drifted together.
400
What is sea-floor spreading?
Sea-floor spreading is a process that continually adds new material to the ocean floor.
The sea floor speads apart along both sides of a mid-ocean ridge as new crust is added.
400
Any trace of an ancient organism that has been preserved in rock is called...
A fossil
500
Describe Earth's outer core.
Earth's outer core is a layer of molten metal that surrounds the inner core. The outer core is liquid.
500
What three types of evidence did Alfred Wegener use to support his theory?
Land features, fossils, and evidence of climate change.
500
Where does most sea-floor spreading occur?
at the mid-ocean ridge.
500
What have geologists learned about Earth's interior using seismic waves?
Geologists have learned that Earth's interior is made up of several layers.