Name: ______

Period: ______

Plate Tectonics, Earthquakes & Volcanoes Study Guide

Find the answers to the following questions in your Note-taking Worksheet and in Chapter 7 (pgs 182-199) and Chapter 8 (pgs 210-231) in your textbook.

  1. Name the theory that states continents have moved slowly to their current locations.

Continental Drift

  1. Who proposed the theory from question 1?

Alfred Wegener

  1. List 5 different pieces of evidence supporting the theory from question 1.
  • Rock formations
  • Plants in different climates
  • Glacial deposits
  • Animal fossils
  • Puzzle like shape
  1. The continents were once believed to be one large landmass called ___Pangaea____.
  1. How did scientists discover a system of underwater mountain ranges?

Echolocation; sound waves

  1. Who was the scientist who discovered the mid-ocean ridge?

Harry Hess

  1. What evidence supports seafloor spreading?
  • Magnetic field
  • Youngest rocks at mid ocean ridge
  1. What part of the earth’s layers make up the plates?

Crust and upper mantle

  1. The layers of earth from question 7 make up the __lithosphere______.
  1. The plastic-like layer below the lithosphere is called the ___asthenosphere______.
  1. List the 3 different plate boundaries and describe how they move.
  • Convergent – move towards each other
  • Divergent – move away from each other
  • Transform – slide past one another
  1. List 5 different features caused by plate tectonics.
  • Mountains
  • Islands
  • Rift valleys
  • Volcanoes
  • Earthquakes
  • Deep sea trenches
  • mid ocean ridge
  1. Define the following key terms:
  • Focus-origin of earthquake under ground
  • Epicenter-point on earth’s surface above origin
  • Tsunami-ocean wave caused by earthquakes
  • Subduction Zone-area where one plate slides under another
  • Sea-floor spreading–theory that the sea floor is spreading apart at the mid ocean ridge
  • Convection currents – cycle of rising heat and sinking cool that causes the plates to move
  • Hot spots – large bodies of magma that are pushed toward surface.
  1. What instrument do scientists use to measure an earthquake’s vibrations? – seismograph
  1. Earthquakes produce ___seismic______waves.
  1. Name the scale used to measure an earthquakes size. Richter Scale
  1. Define the following key terms:
  • Volcano-cone shaped mountain that erupts
  • Magma-molten rock that is below the Earth’s surface
  • Lava-molten rock that is on the Earth’s surface
  • Pyroclastic Flow-cloud of dust, rock and hot gases that erupt from a volcano
  1. List 3 types of volcanoes and describe the shape, composition and type of eruption for each.

Shield volcano – gentle eruptions, gently sloping sides

Composite volcano – steep sides, combination of eruptions, layered with tephra and rock

Cinder-Cone volcano – steep sides, violent eruptions