Across
- 2. the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side
- 4. the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate
- 7. a 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
- 8. changes in direction or orientation of the magnetic field of the Earth that have occurred from time to time
- 10. the hypothetical landmass that existed when all continents were joined
- 13. an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide
- 14. a line on a diagram or map connecting points relating to the same time or equal times
- 15. a proposed mechanism for plate motion in plate tectonics
Down
- 1. the lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates
- 3. the gradual movement of the continents across the earth's surface through geological time
- 5. a fault zone where two plates slide past each other horizonatally
- 6. a linear feature that exists between two tectonic plates that are moving away from each other
- 9. the portion of motion of a tectonic plate that can be accounted for by its subduction
- 11. an instrument used for measuring magnetic forces, especially the earth's magnetism
- 12. the branch of geophysics concerned with the magnetism in rocks that was induced by the earth's magnetic field at the time of their formation