Layers of the Earth
What is the outermost solid layer of the Earth called?
What are the large pieces of Earth’s crust that move slowly over the mantle called?
Tectonic plates
What currents in the mantle cause plates to move?
Convection currents
Who proposed the theory of continental drift?
Alfred Wegener
What forms when two continental plates collide?
Mountains
Which layer is made of molten rock and drives plate movement?
The mantle
What is the boundary called where plates move apart?
Divergent boundary
What force pulls plates downward at subduction zones?
Slab pull
What was the name of the supercontinent in Wegener’s theory?
Pangaea
What forms when an oceanic plate subducts under a continental plate?
Volcanoes
Which layer is liquid and creates Earth’s magnetic field?
The outer core
What is the boundary called where plates collide?
Convergent boundary
What force pushes plates apart at mid-ocean ridges?
Ridge push
What type of evidence from ancient plants supported continental drift?
Fossil evidence
What occurs when plates slide past each other?
Earthquakes
Which layer is solid and extremely hot at the center of Earth?
The inner core
What is the boundary called where plates slide past each other?
Transform boundary
Which layer allows plates to move because it is semi-fluid?
The asthenosphere
What type of evidence from matching mountain ranges supported continental drift?
Geological evidence
What is the name of the famous fault in California that is a transform boundary?
The San Andreas Fault
What do we call the rigid layer made of the crust and upper mantle?
The lithosphere
What process occurs at divergent boundaries under oceans?
Seafloor spreading
What is the source of heat that drives convection currents?
Radioactive decay in the core
What modern evidence from the ocean floor helped confirm the theory of continental drift and led to the development of plate tectonics?
The discovery of seafloor spreading at mid-ocean ridges, along with symmetrical patterns of magnetic striping in oceanic crust.
What ocean feature forms at divergent boundaries?
Mid-ocean ridges