Across
- 2. Scale / the magnitude of seismic energy released during an earthquake is measured by the Richter scale. A quake magnitude is determined by measuring the amplitude of the largest wave recorded on the seismogram. The larger the amplitude, the greater is the displacement of the recording pen and the greater the earthquake. (sensitivity of seismograph and distance of station from quake must be adjusted for in the calculation).
- 6. waves / seismic vibrations that move through the Earth's interior. They are classified into:
- 8. waves or P waves / push-pull waves, waves move back and forth in the direction in which the wave is travelling. Change both volume and shape of material in which they pass. Affect and can pass through solids, liquids, and gasses (as they all exhibit resistance to change in volume). Also called Longitudinal Waves= wave motion (amplitude) is parallel to direction of travel, e.g. accordion motion, to and from.
- 9. / the point on the Earth's surface vertically above the focus of an earthquake, i.e. directly above the true centre of the seismic disturbance from which the shock waves of an earthquake seem to radiate. The epicentre usually registers the strongest shaking.
- 10. waves or S waves / vibrations occurring at right angles to direction of wave propagation. They are shake-waves (shear waves), vibrating side-to-side. They are not as fast as P-waves and result in changing only shape of material they travel through. Affect and can pass through only solid materials (only solids offer resistance to change in shape). Also called Transverse Waves = wave motion (amplitude) is perpendicular to direction of travel, e.g. spring bobbing, up and down.
- 12. plane / the planar (flat) surface along which two blocks of the earth's crust suddenly slip past one another during an earthquake
- 13. / these are smaller earthquakes in the same area as the following larger earthquake. Until the larger earthquake hits scientists are unable to predict if they are foreshocks.
- 14. / the size of the wiggles on an earthquake recording.
- 15. Fault / earthquake faults are fractures where displacement is on either side relative to one another and parallel to the fracture.
- 16. / the point inside the Earth where the rock breaks off and pressure is released, The focus point generally occurs 45 miles below the ground.
Down
- 1. Waves / elastic energy that travels as waves through the Earth's crust at speeds of several miles per second and is propagated or transmitted outward radially from the focus of an earthquake.
- 3. / the location below the Earth’s surface where an earthquake rupture begins.
- 4. / a number that categorizes the amount of energy released during an earthquake.
- 5. / the largest, main earthquake.
- 7. / smaller earthquakes that occur after the main earthquake in the same place as the mainshock. Aftershocks are linked to the size of the mainshock and if this is large can continue for many weeks, months or years.
- 11. tectonics / plate tectonics are the science of the process where rigid plates move across hot molten material. It helps explain the formation of mountains and the distribution of earthquakes and volcanoes.
- 16. depth of an earthquake / the depth of the hypocentre below the Earth's surface.