Deck 4: Tsunamis

Question 1

Which of the following is NOT an effect that can be caused by tsunamis?

A) Increased volcanic activity
B) Fires
C) Contaminated water supplies
D) Disease
E) Coastline erosion

Answer 1

A

Question 2

Which of the following regions has the LEAST risk from tsunamis?

A) Japan
B) Pacific Northwest coast of the U.S.
C) Northeastern coast of the Indian Ocean
D) Hawaii
E) Atlantic coast of the U.S.

Answer 2

E

Question 3

Which of the following describes the tsunami in Lituya Bay, Alaska in 1958?

A) M 9 earthquake triggered a 10 m tsunami (up to 40 m high in certain locations), which caused the meltdown of 3 nuclear reactors and killed more than 20,000 people in a country that has many high seawalls that were built to protect it from tsunamis.
B) M 9 earthquake triggered a 10 m tsunami, which was the deadliest tsunami ever, killing more than 200,000 people in several countries.
C) M 7.7 earthquake triggered a massive landslide, which fell into the water and caused water to surge over 500 m above the normal water level.
D) Volcanic explosion caused part of the volcano to collapse into the ocean, producing a 35 m tsunami that killed 36,000 people.

Answer 3

C

Question 4

Which of the following describes the tsunami in Indonesia in 2004?

A) M 9 earthquake triggered a 10 m tsunami (up to 40 m high in certain locations), which caused the meltdown of 3 nuclear reactors and killed more than 20,000 people in a country that has many high seawalls that were built to protect it from tsunamis.
B) M 9 earthquake triggered a 10 m tsunami, which was the deadliest tsunami ever, killing more than 200,000 people in several countries.
C) M 7.7 earthquake triggered a massive landslide, which fell into the water and caused water to surge over 500 m above the normal water level.
D) Volcanic explosion caused part of the volcano to collapse into the ocean, producing a 35 m tsunami that killed 36,000 people.

Question 5

A tsunami is a wave in the ocean

A) usually caused by earthquakes.
B) usually caused by tides.
C) usually caused by hurricanes.
D) seen only in Japan.
E) seen only in the summer months.

Question 6

Why don't earthquakes on transform faults trigger tsunamis?

A) The earthquakes aren't strong enough.
B) The earthquakes aren't in the ocean.
C) The earthquakes don't vertically displace the water in the ocean.
D) The earthquakes don't move fast enough.
E) The earthquakes don't horizontally displace the water in the ocean.

Question 7

Which of the following describes what happens to tsunami waves as they move towards the shore?

A) Increase in amplitude and decrease in speed
B) Decrease in amplitude and increase in speed
C) Decrease in both amplitude and speed
D) Increase in both amplitude and speed

Question 8

Which of the following describes the tsunami at Krakatoa in 1883?

A) M 9 earthquake triggered a 10 m tsunami (up to 40 m high in certain locations), which caused the meltdown of 3 nuclear reactors and killed more than 20,000 people in a country that has many high seawalls that were built to protect it from tsunamis.
B) M 9 earthquake triggered a 10 m tsunami, which was the deadliest tsunami ever, killing more than 200,000 people in several countries.
C) M 7.7 earthquake triggered a massive landslide, which fell into the water and caused water to surge over 500 m above the normal water level.
D) Volcanic explosion caused part of the volcano to collapse into the ocean, producing a 35 m tsunami that killed 36,000 people.

Question 9

Which region has the LEAST risk for tsunamis?

A) Shorelines in the Indian Ocean
B) Shorelines in the Pacific Ocean
C) Shorelines in the Mediterranean Sea
D) Shorelines in the Atlantic Ocean
E) All shorelines have a similar risk for tsunamis

Question 10

An important reason for the extraordinarily high death toll in the Indonesian tsunami of 2004 around the Indian Ocean was that

A) people ignored warning sirens that were sounding and instead went to coastal areas to watch the incoming tsunami.
B) panicking elephants created a stampede that crushed many people.
C) there was no warning system to alert people to evacuate.
D) buildings were not built to withstand a tsunami.
E) tsunamis had never occurred in that area before.

Question 11

A tsunami refers to

A) an extremely large storm-generated wave.
B) a large, fast, earthquake-generated water wave.
C) an earthquake that occurs in Japan.
D) an unusual type of vibration that occurs in areas where the ground is very weak.

Question 12

Which is the best explanation for how earthquakes cause tsunamis?

A) Earthquakes shift the seafloor upward or downward, causing water to be vertically displaced.
B) Earthquakes shake the water, causing the ripples to move outward in all directions.
C) Earthquakes cause a release of gas on the seafloor that causes water to be displaced.
D) Earthquakes heat ocean water, causing it to expand and move as a wave.
E) Earthquakes transmit seismic waves, especially s-waves, upwards through the seawater and when the seismic waves reach the surface, they release that energy in the form of water waves.

Question 13

Which of the following normally CANNOT produce tsunamis?

A) Submarine landslides
B) Volcano collapse
C) Earthquakes at subduction zones
D) Earthquakes at mid-ocean ridges
E) Asteroids

Question 14

Which of the following locations has NOT experienced a major tsunami in the last 20 years?

A) Japan
B) Maldives
C) Indonesia
D) New York City

Question 15

Which shorelines are at greatest risk for tsunamis?

A) All shorelines have a similar risk for tsunamis.
B) Near hotspots
C) Near transform plate boundaries
D) Near subduction zones
E) Near mid-ocean ridges

Question 16

What is "runup"?

A) The farthest horizontal and vertical distance that tsunami waves move inland
B) Speed of a tsunami wave as it nears the shore
C) Speed of a tsunami wave when it is on land
D) Amount of damage done by a tsunami wave
E) Number of tsunami waves produced by an earthquake

Question 17

Which of the following describes the tsunami in Japan in 2011?

A) M 9 earthquake triggered a 10 m tsunami (up to 40 m high in certain locations), which caused the meltdown of 3 nuclear reactors and killed more than 20,000 people in a country that has many high seawalls that were built to protect it from tsunamis.
B) M 9 earthquake triggered a 10 m tsunami, which was the deadliest tsunami ever, killing more than 200,000 people in several countries.
C) M 7.7 earthquake triggered a massive landslide, which fell into the water and caused water to surge over 500 m above the normal water level.
D) Volcanic explosion caused part of the volcano to collapse into the ocean, producing a 35 m tsunami that killed 36,000 people.

Question 18

Which of the following case histories did NOT involve a tsunami?

A) Kobe, Japan in 1995
B) Indonesia in 2004
C) Tōhoku, Japan in 2011
D) Lituya Bay, Alaska in 1958

Question 19

What is the difference between a distant tsunami and local tsunami?

A) Distant tsunamis aren't dangerous.
B) Distant tsunamis move farther from their source before they hit land.
C) Distant tsunamis are larger than local tsunamis.
D) Distant tsunamis are triggered in remote parts of the ocean whereas local tsunamis are triggered near the continents.
E) Distant tsunamis hit the same area after the local tsunamis.

Question 20

Why don't boats in the open ocean notice a tsunami approaching?

A) Boats will usually mistake the large waves for tidal waves and not recognize them as tsunamis.
B) Tsunamis are too small in amplitude in the open ocean and the distance between crests is too large for boats to notice their passing.
C) Because tsunamis are produced by earthquakes, the boats are probably still recovering from the initial tremors to notice a change in the water waves.
D) Tsunami waves don't break and therefore won't be noticed by boats.
E) The statement is false. Tsunami waves are always noticed by boats in the open ocean.

Question 21

What does it mean when a tsunami watch has been issued for an area?

A) A tsunami is on its way.
B) It is time to go down to the shoreline to watch for the tsunami.
C) It is time to evacuate all areas of the shoreline as quickly as possible.
D) A tsunami trigger has occurred and forecasters are watching for detection of a tsunami.

Question 22

Which of the following is NOT a typical problem of erosion by tsunamis?

A) Erosion damages structures built by humans.
B) Erosion removes some of the shoreline, which causes valuable land to be unusable.
C) Erosion shortens the shoreline, which makes the new shoreline more vulnerable to future wave erosion.
D) Erosion dislodges native vegetation that is useful as a barrier against future wave erosion.
E) Erosion creates waterfalls in coastal river channels, making navigation by boats dangerous.

Question 23

A "runup map" shows where

A) river floods are most likely to occur.
B) people should flee during a tsunami.
C) the greatest tsunami amplitudes have been in the past.
D) water is likely to rise in an area during tsunamis of various sizes.
E) emergency supplies should be located during any coastal hazard.

Question 24

Tsunamis can be caused by triggers other than earthquakes.

Question 25

Which of the following signs should NOT cause a person to leave a coastal area due to the threat of a tsunami?

A) An earthquake is felt near a susceptible coastline area.
B) The ocean begins to recede showing the ocean floor.
C) A tsunami siren is heard.
D) A giant wall of water is seen moving towards the beach.
E) Change in wind direction from blowing onshore to blowing offshore.

Question 26

Does human activity affect the magnitude, i.e., the amplitude, of tsunamis?

A) Yes. Human structures on the shoreline increase the wave amplitude.
B) Yes. Human use of the water increases the wave amplitude.
C) Yes. Human use of the water decreases the wave amplitude.
D) Yes. Global warming increases the wave amplitude.
E) No. Human activity does not increase or decrease the wave amplitude.

Question 27

All tsunamis in recorded history have occurred in the Pacific Ocean.

Question 28

People on the African Coast had only minutes to prepare for the Indonesian tsunami of 2004.

Question 29

Which of the following is NOT a part of tsunami detection and warning?

A) Seismographs
B) Tidal gauges
C) Buoy sensors
D) Tsunameter
E) Sling psychrometers

Question 30

Tsunamis in the open ocean are big enough to capsize freighters and other large boats.

Question 31

Any earthquake in the oceanic crust has the potential to cause a tsunami to form, it mainly depends on the direction that the rocks move during faulting.

Question 32

How are fires started after a tsunami?

A) Fires are started after gas lines break and catch on fire.
B) Fires are started by molten lava that erupts from the subduction zone.
C) Fire is brought along with the tsunami as it moves.
D) Fires are started when people build fires after the tsunami for heat.
E) Fires are not associated with tsunamis because it is too wet.

Question 33

Which of the following are hazards that are NOT related to tsunamis in some way?

A) Erosion
B) Volcanic activity
C) Earthquakes
D) Hurricanes
E) Asteroids

Question 34

Structural Control is a way of controlling

A) building design near the shoreline to reduce future tsunami damage.
B) planes of weakness in rock near the shoreline.
C) the tsunami as it moves.
D) the movement along the fault.
E) the water flow on the shoreline.

Question 35

Before a tsunami arrives, sea level often drops exposing the seafloor.

Question 36

If Japan had a tsunami warning system, then many of the deaths in the 2011 tsunami would have been prevented.

Question 37

Which of the following is NOT a way to minimize the hazard from tsunamis?

A) Greater emphasis on detection and warning systems
B) Stricter building codes for structures on vulnerable coastlines
C) Increased planting of native vegetation to break waves
D) Educate people about what to do during a tsunami
E) Prohibit hydraulic fracturing for natural gas

Question 38

Is it possible to predict the arrival time of a tsunami in distant areas after a major earthquake?

A) Yes
B) No, the calculations of a tsunami's arrival time are very time-consuming and cannot be completed before the tsunami arrives.
C) No, tsunami behavior is poorly understood and calculations of a tsunami's arrival time are not possible at this time.
D) Sometimes, depending on whether or not the wave splits into a distant and local tsunami

Question 39

Which of the following is NOT a natural service function of tsunamis?

A) Tsunamis bring in nutrients from the ocean to the soil.
B) Tsunamis bring in sediment to some coastlines.
C) Flooding from tsunamis clears out waste from waterways.
D) Tsunamis bring in nutrients for fish and wildlife.
E) Tsunamis provide to coastal areas a new dynamic ecosystem that is better adapted to the area than the previous one.

Question 40

A tsunami is a large ocean wave that is most commonly produced when a large earthquake rupture in oceanic crustal rock pushes seawater upwards or downwards.

Question 41

Explain how asteroids and volcanic eruptions are linked with tsunamis.

Question 42

Coastlines that are far from subduction zones have a lower risk for tsunamis compared to coastlines that are near to subduction zones.

Question 43

There is no way to know where a tsunami is likely to occur.

Question 44

There is little chance of another devastating tsunami in Indonesia over the next 100 years because of the tsunami in Indonesia within the past 15 years.

Question 45

It is possible to examine the geologic record for ancient tsunamis that were not recorded by humans.

Question 46

There are no natural service functions of tsunamis; they only cause negative impacts such as death and destruction.

Question 47

A locked fault in a subduction zone represents a major threat for producing a large tsunami.

Question 48

Tsunamis can result in fires and polluted water supplies after they strike an area.

Question 49

Describe the likely cause of a tsunami in the Pacific Northwest of the United States.

Question 50

Tsunamis have enough erosional power to alter the landscape of coastlines that they hit.

Question 51

It was said that scuba divers who were out in the ocean came up after the Indonesian tsunami passed to find the land devastated. They didn't see a thing. Could that have happened? Explain why or why not.

Question 52

Buoys in the open ocean can detect the passage of a tsunami.

Question 53

Probability analysis can now tell us precisely when and where a tsunami is likely to occur.

Question 54

A single tsunami produces one wave, either a local tsunami or a distant tsunami.

Question 55

One of the largest tsunami waves on record was triggered by a rockfall into a bay. Explain how the rockfall would trigger the tsunami and why it would have been so large.

Question 56

If you can see the tsunami coming, you could probably just wait for it and swim to safety.

Question 57

Usually, there is only one wave from the tsunami and once it recedes people may return to their homes.

Question 58

A tsunami can NEVER strike locations on the East Coast of the United States because there are no subduction zones in the Atlantic Ocean.

Question 59

Human activities are making tsunamis more common and larger.

Question 60

The entire eastern U.S. coast has one the highest threats from tsunamis in the world.

Question 61

Explain how a tsunami headed for the Hawaiian Islands might be detected and the public might be warned.

Question 62

If you were an elected local official, how would handle reports that some of the people in your town went to the coastline to look for a tsunami when a tsunami warning was issued?

Question 63

How is a "Run-up Map" created and how does it help to minimize the tsunami hazard?

Question 64

What is Structural Control and how does it help to minimize the tsunami hazard?

Question 65

Describe the likely cause of a tsunami for the East Coast of the United States.

Question 66

Human activity does not affect tsunami magnitude or frequency. This being the case, how should humans deal with the tsunami threat?

Question 67

The East Coast United States is at risk for tsunami.

A) Describe the possible trigger for this tsunami.
B) Explain what effects the tsunami could have for East Coast areas.
C) Describe how officials might warn people once the tsunami is triggered.
D) Do you think that U.S. officials could prevent a catastrophe for the East Coast if the tsunami were to be triggered?

Question 68

The Indonesian tsunami was one of the worst natural disasters on record.

A) Explain the most important reasons why you think that it became the disaster that it did.
B) If you were in charge of making a mitigation plan for Indonesia, what are the three most important things that you would put in place and why.

Question 69

The Pacific Northwest of the United States is at risk for tsunami.

A) Describe the possible trigger for this tsunami.
B) Explain what officials might do to prepare the public for the possible disaster.
C) Do you think that preparations are adequate to prevent a catastrophe for the Pacific Northwest?

Question 70

The Indonesian tsunami began with an earthquake from subduction zone. Explain what each of the following people would have seen during the tsunami.

A) A person in a cruise ship in the ocean, near the subduction zone .
B) A person swimming in the ocean, but near the shoreline closest to the subduction zone.
C) A person on the land closest to the subduction zone, but a quarter mile from the shoreline.
D) A person on the land far from the subduction zone, but near the shoreline of the ocean that the tsunami travelled in.