Unit 2 - The Changing Earth

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Across
  1. 1. The oceanic crust is the crust that forms the ocean floor, for example, the Pacific Plate.
  2. 3. The Sea Floor Spreading is the process of new crust forming at the ocean ridges and spreading outwards, for example, this happens at the Mid-Atlantic Ridge.
  3. 4. The crust that forms the continents, for example, the Eurasian Plate.
  4. 5. A focus is the place below the ground where an earthquake starts
  5. 6. A convection current is a current caused by hot magma in the mantle rising, cooling, sinking and heating in a process that happens again, for example, convection currents occur in the mantle
  6. 9. Subduction is when a oceanic plate collides with a continental plate, and the oceanic plate then sinks below the continental plate because it is more dense.
  7. 12. A volcano is a place where extremely hot material from the Earth erupts at the surface, for example, Iceland is made up of volcanoes.
  8. 13. of magnesium-iron silicate minerals.
  9. 14. A divergent boundary is where plates are moving apart from each other in opposite directions, for example, The North American Plate and The Eurasian Plate.
  10. 18. A seismometer is an instrument that detects the seismic waves from an earthquake.
  11. 19. The core is the central or innermost portion of the Earth, lying below the mantle and probably consisting of iron and nickel.
  12. 20. Plate tectonics is a theory that’s the Earth's crust is cracked into many large pieces that move on the asthenosphere, for example, the Pacific Plate.
  13. 23. The mantle is the layer of the Earth between the crust and the core that consists
  14. 24. A earthquake is the rapid movement of the ground, usually back and forth and up and down in a wave motion due to the movement of tectonic plates, for example, many earthquakes occur in New Zealand.
Down
  1. 2. A transform boundary is where plates are sliding parallel to each other but in opposite directions, for example, San Andrea's Fault line.
  2. 6. A convergent boundary is where plates are colliding with each other, for example, The Pacific plate and the North American Plate.
  3. 7. An ecosystem is a group of plants, animals and bacteria that work together to remain healthy.
  4. 8. A secondary wave is a transverse seismic wave that travels through the earth.
  5. 10. The continental drift is the separating of continents by drifting across the oceans, for example, Australia was once attached to Antarctica.
  6. 11. Magnetic Striping is the patterns of magnetism trapped in rocks on each side of plate boundaries.
  7. 15. A tsunami is a huge wave in the ocean caused by an earthquake occurring on the seafloor.
  8. 16. An ocean trench is a deep trench in the ocean floor that is much deeper than the ocean floor, for example, The Philippine Trench.
  9. 17. The asthenosphere is a layer of 'plastic' semi-solid rock in the lower mantle.
  10. 20. A primary wave is a longitudinal seismic wave that travels fast through the earth.
  11. 21. A seismic wave is the skaing, wave-like movement of the ground in an earthquake.
  12. 22. An epicentre is the point on the Earth's surface directly above the focus of an earthquake.