Seafloor Spreading

5. A fracture or zone of fractures between two blocks of rock, which can cause earthquakes when the rocks move.
7. Crust The thinner, denser part of Earth's crust that forms the ocean floors, primarily composed of basalt.
9. A sudden and violent shaking of the ground caused by the movement of tectonic plates along faults.
11. The rigid outer layer of Earth, consisting of the crust and the upper mantle, which is broken into tectonic plates.
12. The preserved remains or traces of ancient organisms, often used as evidence for plate tectonics by showing the past distribution of species across continents
13. The regions where two tectonic plates meet, which can be convergent (plates collide), divergent (plates move apart), or transform (plates slide past each other).

1. Spreading The process by which new oceanic crust is formed at mid-ocean ridges as tectonic plates move apart, causing the sea floor to expand.
2. Molten rock beneath the Earth's surface that, when it erupts from a volcano, is called lava.
3. Reversal A change in Earth’s magnetic field where the positions of magnetic north and south switch places.
4. An opening in the Earth's crust where magma, ash, and gases erupt onto the surface.
6. The innermost layer of Earth, consisting of a solid inner core and a liquid outer core, primarily composed of iron and nickel.
7. Ridge An underwater mountain range formed by plate tectonics, typically at divergent boundaries where seafloor spreading occurs (e.g., the Mid-Atlantic Ridge).
8. The outermost layer of the Earth, where we live, which includes both the continental crust (land) and oceanic crust (under the oceans).
10. Tectonics The theory that Earth's outer shell is divided into several plates that glide over the mantle, explaining the movement of continents, earthquakes, and volcanoes.