| A | B |
|---|
| plasticlike layer of Earth below the lithosphere | asthenosphere |
| mantle's cycle of heating, rising, cooling, and sinking | convection current |
| Theory stating that Earth's crust and upper mantle are broken into sections | plate tectonics |
| Area where an ocean plate descends into the upper mantle | subduction zone |
| plate boundary that occurs when two plates slide past one another | transform fault |
| Place where two plates collide | convergent boundary |
| Rigid layer composed of Earth's crust and part of the upper mantle | lithosphere |
| Instrument that records magnetic fields that help confirm seafloor spreading | magnetometer |
| Name given to the landmass when all continents were connected | pangaea |
| Idea that continents have moved horizontally through the seafloor to their current locations | continental drift |
| Place where two plates move away from each other | divergent boundary |
| Broken sections of the lithosphere | plates |
| Largest layer of Earth, composed mostly of silicon, oxygen, magnesium, and iron | mantle |
| Earth's outermost layer | crust |
