Across
- 3. sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.
- 4. strike-slip fault that offsets a mid-ocean ridge in opposing directions on either side of an axis of seafloor spreading.
- 5. is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide.
- 7. instrument used for measuring magnetic forces, especially the earth's magnetism.
- 8. a linear feature that exists between two tectonic plates that are moving away from each other.
- 10. hypothetical landmass that existed when all continents were joined, from about 300 to 200 million years ago.
- 11. the movement of the Earth's continents relative to each other, thus appearing to "drift" across the ocean bed.
- 13. line on a diagram or map connecting points relating to the same time or equal times.
- 14. is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
- 15. the portion of motion of a tectonic plate that can be accounted for by its subduction.
Down
- 1. is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.
- 2. the theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core.
- 6. the United Kingdom) is the study of the record of the Earth's magnetic field in rocks, sediment, or archeological materials. Certain minerals in rocks lock-in a record of the direction and intensity of the magnetic field when they form.
- 9. a proposed mechanism for plate motion in plate tectonics.
- 12. large elongated depression with steep walls formed by the downward displacement of a block of the earth's surface between nearly parallel faults or fault systems.