Across
- 1. a numerical scale for expressing the magnitude of an earthquake on the basis of seismograph oscillations. The more destructive earthquakes typically have magnitudes between about 5.5 and 8.9; the scale is logarithmic and a difference of one represents an approximate thirtyfold difference in magnitude.
- 4. a powerful tropical cyclone with sustained winds exceeding 74 mph.
- 5. an opening in the Earth's crust through which lava, ash, and gases erupt.
- 7. a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
- 10. a flow of soil or fine-grained sediment mixed with water down a steep unstable slope.
- 12. a period of time when an area or region experiences below-normal precipitation.
- 13. when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking.
- 16. a dense, fast-moving flow of solidified lava pieces, volcanic ash, and hot gases.
- 17. provides an estimate of earthquake size that is valid over the complete range of magnitudes
Down
- 2. violently rotating columns of air, extending from a thunderstorm, which are in contact with the ground.
- 3. when something is collapsing on itself.
- 6. streams of molten rock that pour or ooze from an erupting vent.
- 8. the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance
- 9. ocean waves triggered by: Large earthquakes that occur near or under the ocean.
- 11. An overflow of water onto normally dry land.
- 14. a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.
- 15. a mass movement of material, such as rock, earth or debris, down a slope.