Download Answer Key - MrTestaScienceClass

Answer Key
1. The Earth’s crust is made of plates that often pass one another to cause earthquakes. What exactly
happened on December 26, 2004? (Explain what plates were involved, etc.)
The Australian plate subducted under the Indonesian plate. The strike-slip friction was released. The top
plate was dragged down and then snapped backward.
2. Where was the epicenter of the earthquake located?
155 miles from Sumatra
3. Where did most of the earthquake’s energy travel?
Toward the East and West
4. What was the magnitude of the earthquake?
9.0 on the Richter Scale
5. Do all earthquakes in the ocean cause tsunamis? Why or why not?
No. It depends upon where the earthquake occurred, what the magnitude was, how much the water above the
epicenter was displaced, etc.
6. How deep was the focus of this earthquake?
30 km below the surface of the crust
7. Tsunamis are virtually undetectable in the open ocean. As they near the shore, the front of the wave
slows. Why does the tsunami become a large surge of water?
The back of the wave does not slow and catches up to the front to amplify the wave, creating a surge or a wall
of water
8. How does the shape of the seabed affect the way the tsunami impacts the coast?
A shallow seabed allows waves to travel very far inland
9. The Sumatran earthquake was extremely forceful. What did this earthquake do to Earth and its rotation?
The earthquake changed rotation of the planet (2.5 cm “wobble), causing the Earth to spin faster, making the
day slightly shorter
10. What are 4 things that can cause tsunamis?
Earthquakes, Asteroids, Volcanoes, Landslides
11. What might happen if a massive landslide occurred off the western (Atlantic) coastline of Africa?
A tsunami could be generated that would hit North America and England
12. What steps are being taken by the United States to protect our coastlines?
The US is adding 32 more tsunami sensors to protect the Pacific, the Atlantic, and the Caribbean
Simulations to aid in building design technology; educating people on how to respond in this situation