Earth’s Onion
This is Earth’s outermost layer, made of solid rock.
What is the crust?
The theory that Earth’s lithosphere is broken into moving pieces.
What is the Theory of Plate Tectonics?
The scientist who proposed the idea of continental drift.
Who is Alfred Wegener?
New crust is formed at these underwater mountain ranges.
What are mid-ocean ridges?
At this type of boundary, two plates move apart.
What is a divergent boundary?
This hot, solid layer of Earth flows slowly and causes convection currents.
What is the mantle?
Earth’s lithosphere is broken into these large, rigid pieces.
What are tectonic plates?
Wegener’s name for the supercontinent that once existed.
What is Pangaea?
Molten material rises and cools at ridges to form this.
What is new oceanic crust?
At this type of boundary, two plates move toward each other.
What is a convergent boundary?
The movement of molten rock in the mantle that drives plate motion.
What are convection currents?
Plate tectonics explains the movement of this type of crust over time.
What is continental crust?
Matching fossils on different continents were one piece of Wegener’s ______.
What is evidence for continental drift?
The process of new ocean crust forming and moving outward from ridges.
What is seafloor spreading?
At this type of boundary, two plates slide past each other.
What is a transform boundary?
Earth’s dense, metallic center is divided into these two parts.
What are the outer core and inner core?
The driving force of plate tectonics is movement in this Earth layer.
What is the mantle?
Wegener’s theory was not widely accepted because he couldn’t explain this.
What is the force that moved the continents?
Magnetic stripes on the ocean floor show reversals of this.
What is Earth’s magnetic field?
Mid-ocean ridges are an example of this kind of boundary.
What is a divergent boundary?
Heat transfer in the mantle that causes warm material to rise and cooler material to sink.
What is convection?
Plate tectonics explains the formation of these three major surface features.
What are mountains, earthquakes, and volcanoes?
The puzzle-like fit of these two continents is strong evidence for continental drift.
What are South America and Africa?
Old ocean crust is destroyed at these plate boundaries.
What are subduction zones (trenches)?
Deep ocean trenches form at this type of boundary.
What is a convergent boundary?