Topic 1 Part 1

2. Smaller seismic events that follow a main earthquake.
5. The exact underground point where rock fractures and slips, marking the physical origin of an earthquake.
7. Using specialised tracking equipment to identify high-risk areas before a tectonic event occurs.
8. A numerical scale from 1 to 10 used to measure the magnitude or energy released during a seismic event.
12. A sudden disturbance within the Earth's crust that releases energy and generates seismic vibrations propagating outward from a central source.
13. Massive sea waves triggered by underwater tectonic displacement.
14. Tools that use a high-tension wire stretched directly across a fault line to warn scientists of soil and fault movement.
16. A gravitational force at mid-ocean ridges where buoyant, newly formed crust cools, becomes denser, and slides downward away from the ridge crest.
18. The process where a denser oceanic plate is forced to slide beneath a less dense continental plate and sink deep into the mantle.
19. Immediate effects occurring during the ground-shaking event, such as structural collapse, casualties, and ground cracking.

1. The scientific theory proposed by Alfred Wegener stating that Earth's continents have moved over geological time relative to each other.
3. The point on the Earth's surface located directly above the focus, typically experiencing the most intense shaking.
4. Ranging devices that track microscopic horizontal shifts in the earth by timing a laser reflection across a fault line.
6. An instrument used to pick up, track, and translate ground vibrations into a written chart.
9. A hazardous phenomenon where violent shaking of loose, water-saturated soils forces water to the surface, instantly turning solid ground into weak, liquid mud.
10. Monitoring sudden spikes in naturally escaping radon gas, which indicates that rocks are fracturing under immense pressure prior to a quake.
11. A gravitational mechanism where the heavy, leading edge of a dense tectonic plate sinks into the mantle at a subduction zone, dragging the rest of the plate behind it.
15. Consequences that occur after and as a direct result of primary impacts, including tsunamis, fires, and disease outbreaks.
17. Proactive steps taken to reduce the effects and damage of a natural hazard rather than trying to stop the event itself.