Plate Tectonics

3. The point on the earth's surface directly above the focus
6. This occur when water mix with volcanic materials
7. The smallest and finest fragments of lava or rock that are ejected by volcanic eruptions
8. A scale that measures the damage caused by an earthquake
10. The zone where plates meet is called plate ...
12. The broken pieces of earth's crust
15. Constant rising and sinking of magma results in convection current causing plates to move is called plate ...
17. A lava that has high temperature, cools and solidifies slowly, has low viscosity and low silica content. So the lava flows quickly
18. A lava that has low temperature, cools and solidifies quickly, has high viscosity and high silica content. So the lava flows slowly
19. A plate boundary when two plates move away from each other
20. A plate boundary when two plates slide past each other
21. Plates move as a result of ... current generated in the mantle

1. A crack in the earth's crust where the rock stressed by plate movements breaks and moves
2. A volcano that has a broad base with gentle slopes formed from basic lava
4. This flow occurs when gases mix with volcanic materials
5. A sudden vibration or tremor of the earth's surface
9. A volcano that consists of alternating layers of lava, ash and cinder. It has gentle slopes at its base and steeper slopes near its top
11. A machine used to detect and record earthquake
13. The source of the earthquake
14. A scale that measures the magnitude of an earthquake
16. A plate boundary when two plates move towards each other