EAPS 106 Exam 2 Study Guide
Unit 4 - Tsunamis
1. Why it is generally not sufficient to be a good swimmer to survive a tsunami
Water just keeps coming (waves contain a vast amount of water). Debris will likely kill you.
2. How subduction zone earthquakes cause a tsunamis
Lifts up sea floor, thus involves full depth of an ocean and large displacement
3. How big does a subduction zone earthquake has to be to generate a large tsunami
M9 or larger between
seafloor
4. The differences between wind-blown and tsunami waves
Tsunami waves can have similar height, but carries a much larger volume of water, have a much
longer wavelength, and travel much further inland, tsunamis impacted by seafloor topography
5. Why underwater strike-slip faults will not cause tsunamis
Water must be displaced (up or down) to create a large tsunami
6. The characteristics of a tsunami wave in the deep ocean and as it approaches the shore
Deep: long wavelengths, low wave heights, great speed
Shallow: slow down, reduces in wavelength, and increase in wave height
7. When waves moving toward shore typically break
Typically when the wave height is about equal to water depth-below
8. Why inlets (natural harbors) are particularly dangerous places when a tsunami hits
Incoming water becomes trapped and piles up
9. That extremely deadly even many miles inland from the shore
Waves can travels 10’s of km inland w debris
10. The approximate number people who have been killed by tsunamis in the past 1000 years
Hundreds of thousands
11. The history of large tsunamis wave heights in Japan
Japan has had 3 tsunami’s that were 10’s of meters high in the past 400 years
12. What a Japanese tsunami stone is
Marker of where past tsunamis have reached
13. How we know that the Washington and Oregon coasts have experienced numerous large
tsunamis
Sand deposits. Ghost forests (healthy forests that drowned). Native American stories.
, shaking
14. The four main characteristics of tsunami waves you need to know to keep yourself safe
1. Significant shaking near shore: 20-40min before tsunami hits. Head to high ground.
2. Tide goes out very fast and far: 5-10min before the tsunami hits.
3. Massive white water or debris field heading toward you: seconds before tsunami hits.
4. Tsunami consists of 3-10 waves. 2nd or 3rd usually the largest. Don’t go back to shore
until the all clear is given.
15. What a tsunami seawall is
A wall built to try to prevent water from tsunamis from coming inland. No matter how high they
are built, they cannot stop everything.
16. About how long did it take a tsunami wave to cross the Indian Ocean
7 hours
17. Why the death toll was so high during the Indonesian tsunami
Lack of infrastructure, education, and warning systems.
18. How the DART tsunami early warning system works
Pressure sensor on seafloor. Sends measurements to a buoy on the surface, which sends a signal
to the satellite. Satellite sends the signal to early-warning detection systems on land.
19. The various causes of the tsunamis and their potential wave heights
Any process that displaces a large volume of water.
- Landslide
- Volcanic eruption
- Asteroid impact
- Earthquake
Volcanic eruption
- Eruption underwater
- Volcanic blast
- Pyroclastic flow: flows from indonesia eruption pushes water away from the shore
- Caldera collapse
- Subaerial failure
- Submarine failure
20. The process that caused the largest recorded tsunami run-up
Landslide (happens in Norway) (Lituya Bay, Alaska)
21. How tsunamis are generated by the Hawaiian Island
Underwater landslides
22. The mostly likely cause of a tsunami to hit the U.S. east coast
Underwater landslides on flanks of the Canary Islands
Unit 4 - Tsunamis
1. Why it is generally not sufficient to be a good swimmer to survive a tsunami
Water just keeps coming (waves contain a vast amount of water). Debris will likely kill you.
2. How subduction zone earthquakes cause a tsunamis
Lifts up sea floor, thus involves full depth of an ocean and large displacement
3. How big does a subduction zone earthquake has to be to generate a large tsunami
M9 or larger between
seafloor
4. The differences between wind-blown and tsunami waves
Tsunami waves can have similar height, but carries a much larger volume of water, have a much
longer wavelength, and travel much further inland, tsunamis impacted by seafloor topography
5. Why underwater strike-slip faults will not cause tsunamis
Water must be displaced (up or down) to create a large tsunami
6. The characteristics of a tsunami wave in the deep ocean and as it approaches the shore
Deep: long wavelengths, low wave heights, great speed
Shallow: slow down, reduces in wavelength, and increase in wave height
7. When waves moving toward shore typically break
Typically when the wave height is about equal to water depth-below
8. Why inlets (natural harbors) are particularly dangerous places when a tsunami hits
Incoming water becomes trapped and piles up
9. That extremely deadly even many miles inland from the shore
Waves can travels 10’s of km inland w debris
10. The approximate number people who have been killed by tsunamis in the past 1000 years
Hundreds of thousands
11. The history of large tsunamis wave heights in Japan
Japan has had 3 tsunami’s that were 10’s of meters high in the past 400 years
12. What a Japanese tsunami stone is
Marker of where past tsunamis have reached
13. How we know that the Washington and Oregon coasts have experienced numerous large
tsunamis
Sand deposits. Ghost forests (healthy forests that drowned). Native American stories.
, shaking
14. The four main characteristics of tsunami waves you need to know to keep yourself safe
1. Significant shaking near shore: 20-40min before tsunami hits. Head to high ground.
2. Tide goes out very fast and far: 5-10min before the tsunami hits.
3. Massive white water or debris field heading toward you: seconds before tsunami hits.
4. Tsunami consists of 3-10 waves. 2nd or 3rd usually the largest. Don’t go back to shore
until the all clear is given.
15. What a tsunami seawall is
A wall built to try to prevent water from tsunamis from coming inland. No matter how high they
are built, they cannot stop everything.
16. About how long did it take a tsunami wave to cross the Indian Ocean
7 hours
17. Why the death toll was so high during the Indonesian tsunami
Lack of infrastructure, education, and warning systems.
18. How the DART tsunami early warning system works
Pressure sensor on seafloor. Sends measurements to a buoy on the surface, which sends a signal
to the satellite. Satellite sends the signal to early-warning detection systems on land.
19. The various causes of the tsunamis and their potential wave heights
Any process that displaces a large volume of water.
- Landslide
- Volcanic eruption
- Asteroid impact
- Earthquake
Volcanic eruption
- Eruption underwater
- Volcanic blast
- Pyroclastic flow: flows from indonesia eruption pushes water away from the shore
- Caldera collapse
- Subaerial failure
- Submarine failure
20. The process that caused the largest recorded tsunami run-up
Landslide (happens in Norway) (Lituya Bay, Alaska)
21. How tsunamis are generated by the Hawaiian Island
Underwater landslides
22. The mostly likely cause of a tsunami to hit the U.S. east coast
Underwater landslides on flanks of the Canary Islands
