Layers of Earth
The middle layer of Earth.
What is the mantle?
The process occurring at convergent boundaries where a denser plate sinks beneath a lighter one.
What is subduction?
The rigid outer layer of the Earth, consisting of the crust and upper mantle, broken into plates.
What is the Lithosphere?
Today, Antarctica is covered in these.
What are ice sheets?
These helped scientist determine the age of the seafloor and create isochron maps.
What are rock samples?
This supercontinent existed about 250 million years ago, bringing all current continents together.
What is Pangaea?
A boundary where plates move apart, such as the Mid-Atlantic Ridge.
What is a Divergent Boundary?
The plates float on top of this hot, plastic-like layer of the mantle.
What is the Asthenosphere?
Deep, underwater troughs on the seafloor.
What are ocean trenches?
Processes that can wear down mountains.
What are weathering and erosion?
Molten rock below Earth's surface.
What is magma?
A boundary where two plates slide past each other horizontally.
What is a Transform Boundary?
This long, continuous underwater mountain chain is formed by seafloor spreading.
What is the Mid-Ocean Ridge?
Three types of plate boundaries.
What are convergent, divergent, and transform boundaries?
A vent in Earth's crust that can form along convergent boundaries.
What are volcanoes?
Proposed by Alfred Wegener, this theory suggested continents were once joined and have drifted apart.
What is the Continental Drift?
This feature forms when two continental plates collide, pushing up massive mountain ranges.
What are mountains?
The deepest landform on Earth located in the Pacific Ocean.
What is the Mariana Trench?
The Andes are an example of these.
What are fold mountains?
A volcano that forms in the ocean where oceanic plates converge and one plate subducts.
What is an island?
After cooling and crystallizing, this forms new oceanic crust.
What is lava.
The distance tectonic plates move each year.
This specific, active transform boundary in California is responsible for many earthquakes.
What is the San Andreas Fault?
The mechanism that explains Wegener's hypothesis of the Continental Drift.
What is seafloor spreading?
More than 60% of all volcanic activity on Earth occurs here.