Unit 10 Earth Science

Chapter 28 The Changing Earth

Vocabulary Review

Match the letter of the definition on the right with the term on the left. Write the letter in the blank provided. Each set has an extra definition that will not be used.

Set One------

1. _____paleontologist / a. the idea that continents were once a super-continent called Pangea
2. _____cross-cutting relationships / b. for a layered rock, the youngest layer is on top and the oldest layer is on the bottom
3. _____superposition / c. a scientist who studies fossils
4. _____relative dating / d. a method used to determine the order in which geologic events happened
5. _____continental drift / e. the vein of rock is younger than the rock surrounding the vein
f. a rock embedded in another rock is older

Set Two------

1. _____lithosphere /
  1. a process that occurs at divergent tectonic plates

2. _____asthenosphere / b. an ocean mountain range that occurs where tectonic plates diverge
3. _____sea-floor spreading / c. the layer of the mantle below the lithosphere
4. _____mid-ocean ridge / d. Earth’s crust plus the rigid, upper layer of the mantle

Unit 10 Earth Science

Chapter 28 The Changing Earth

5. _____original horizontality / e. sediment forms horizontal layers under the influence of gravity
f. a feature at convergent tectonic plates

Unit 10 Earth Science

Chapter 28 The Changing Earth

Concept Review

  1. After a minor earthquake, a Los Angeles, California, newspaper’s headline reads “Blame Plate Tectonics.” What do you think this means?
  1. You have good friends who recently moved to an area of the United States that is known to have strong earthquakes. What are two good safety tips you could give them to help keep them safe during an earthquake?
  1. You have determined that the distance from your location to an earthquake’s epicenter is 1,200 miles. Do you know the precise geographic location of the earthquake? Explain.
  1. Assume that earthquake P-waves travel through Earth at an average rate of 6 km/sec and S-waves at an average rate of 4 km/sec. Your seismograph shows the S-waves arriving 90 seconds after the P-waves. How far away is the epicenter?
  1. A partially fossilized skeleton of an extinct marine dinosaur (ichthyosaurus) has been uncovered near the top of a hill (elevation 350 m) that is 600 km from any ocean.
  1. How do you think this animal got there?
  1. How might you go about estimating the relative age of this dinosaur?
  1. The concept of plate tectonics provides explanations for the causes of earthquakes and volcanoes. The east coast of the United States lies on the North American tectonic plate, yet it has little or no volcanic or earthquake acitivity.
  1. Why do you think this is?
  1. Has it always been this way along the eastern United States? What evidence might you look for to support your answer?