Chapter 4 Clickers Natural Hazards Fourth Edition Tsunamis

Tsunamis are most commonly produced by a) b) c) d) e) asteroid impact. collapse of part of a volcano into the sea. submarine volcanic explosions. None of the answers are correct. earthquakes. © 2015 Pearson Education, Inc.

Why do sailors rarely notice a tsunami passing in the open ocean? a) Since tsunamis are produced by earthquakes, the boats are still recovering from the initial tremors to notice a change in the waves. b) This is false – tsunami waves are always noticed in the open ocean by sailors and provide some of the first warnings. c) Tsunami waves do not break; therefore, they are noticed by boats as they pass. d) They usually mistake the large waves for tidal waves and do not recognize them as a tsunami. e) Tsunamis are too small in amplitude in the open ocean, and the distance between crests is too large to notice its passing. © 2015 Pearson Education, Inc.

What happens as a tsunami nears land? a) The height of the waves decreases due to a decrease in both water depth and tsunami velocity. b) The height of the waves decreases due to a decrease in water depth and increase in tsunami velocity. c) The height of the waves increases due to a decrease in water depth and increase in tsunami velocity. d) The height of the waves increases due to a decrease in both water depth and tsunami velocity. e) The height of the waves increases due to a decrease in water depth and no change in tsunami velocity. © 2015 Pearson Education, Inc.

If Kilauea Volcano in Hawaii collapsed into the Pacific Ocean, areas of Oregon may experience a a) b) c) d) e) local tsunami distant tsunami primary tsunami reduced tsunami secondary tsunami © 2015 Pearson Education, Inc.

The two waves created from a single wave (as seen in the figures) are called the a) b) c) d) e) primary and secondary tsunami waves deep and shallow tsunami waves local and distant tsunami waves major and minor tsunami waves upper and lower tsunami waves © 2015 Pearson Education, Inc.

A local tsunami a) b) c) d) e) can arrive quickly, giving little warning time. is the same height as the initial tsunami wave. strikes remote shorelines. heads away from nearby land. travels out across the deep ocean. © 2015 Pearson Education, Inc.

Besides the lack of a warning system, a major reason many lives were lost in the 2004 Indonesian Tsunami was a) the lack of proper transportation. b) the lack of knowledge /education on tsunamis and their behavior. c) the lack of time to retreat in all locations the tsunami hit. d) amount of hotels along the coast. e) a large volume of debris. © 2015 Pearson Education, Inc.

How do humans increase the risk of tsunami hazards? a) b) c) d) All of these are ways humans increase the risk. Building strong structures near the coast. Planting trees as buffer zones. Moving to the coasts where the effects of tsunamis are greatest. e) Participating in activities that increase the magnitude and frequency of tsunamis. © 2015 Pearson Education, Inc.

Which is not a way a tsunami hazard can be minimized? a) b) c) d) e) land-use planning clearing all coastal vegetation construction of runup maps structural control detection and warning systems © 2015 Pearson Education, Inc.

What is a problem with building seawalls to protect against a tsunami? a) b) c) d) e) They can block the views of the houses on the coast. They could lead to a false sense of security if not high enough. They never work. They will trap water inland. There are no problems with seawalls. © 2015 Pearson Education, Inc.

What is a problem with building seawalls to protect against a tsunami? a) They can block the views of the houses on the coast. b) They could lead to a false sense of security if not high enough. c) They never work. d) They will trap water inland. e) There are no problems with seawalls. © 2015 Pearson Education, Inc.

How could a community/state/country best use a runup map to prepare for a tsunami? a) Determine the only locations to implement all their hazard minimization strategies. b) Scare those in the area so they do not build there. c) Runup maps just show possibilities, so they do not help at all. d) Estimate the height of water from a tsunami to not allow any construction in that area. e) Locate the areas most likely to be inundated to possibly move critical services outside these areas. © 2015 Pearson Education, Inc.

What did scientists discover about tropical ecology after the 2004 Indonesian Tsunami? a) No matter what, the vegetation was destroyed. b) Coastal mangrove forests partly protected villages from the energy of the tsunami where the waves were smaller. c) It is best to clear all coastal mangroves so they do not create debris, even in areas where the waves are predicted to be smaller. d) The largest waves created the less damage because of coastal mangrove forests. e) An area should rebuild where the vegetation was destroyed because it has naturally cleared the area for developers. © 2015 Pearson Education, Inc.

What is a difficulty in the probabilistic approach to tsunami hazard risk? a) b) c) d) e) Tsunamis are generally rare events at one particular location. Runup maps are not accurate. There is no statistical method to simulate tsunami events. Scientists still do not know how tsunamis act. There is not enough historical data. © 2015 Pearson Education, Inc.

What is a difficulty in the probabilistic approach to tsunami hazard risk? a) Tsunamis are generally rare events at one particular location. b) Runup maps are not accurate. c) There is no statistical method to simulate tsunami events. d) Scientists still do not know how tsunamis act. e) There is not enough historical data. © 2015 Pearson Education, Inc.

What is the difference between a tsunami watch and a tsunami warning? a) Watch – an event that can cause a tsunami could occur; Warning – an event that can cause a tsunami has occurred. b) Watch – a tsunami will reach the area in more than 3 hrs; Warning – a tsunami will reach the area in less than 3 hrs. c) Watch – a distant tsunami has been detected; Warning – a local tsunami has been detected. d) Watch – an earthquake that can cause a tsunami has occurred; Warning – a tsunami has been detected and is spreading across the ocean towards the area. e) Watch – the waves from the tsunami will be “small”; Warning – the waves from the tsunami will be “large. ” © 2015 Pearson Education, Inc.

Even if a community is “tsunami ready, ” what is still a potential problem? a) b) c) d) e) There will be no problems if they are “tsunami ready” Not doing enough emergency drills Education of the hazard and what to do in a watch or warning Having enough signs in place Not knowing when the tsunami may hit © 2015 Pearson Education, Inc.

Even if a community is “tsunami ready, ” what is still a potential problem? a) There will be no problems if they are “tsunami ready” b) Not doing enough emergency drills c) Education of the hazard and what to do in a watch or warning d) Having enough signs in place e) Not knowing when the tsunami may hit © 2015 Pearson Education, Inc.

When a tsunami watch or warning is issued, you can take your own personal actions. Which is not an action you should take? a) Assume the area is safe because there have not been any dangerous waves elsewhere. b) Run from the beach if you see the ocean recede. c) Stay away from all dangerous areas until an all clear notice is given. d) Move to ground at least 60 ft above sea level in a warning. e) Leave the beach if you feel a strong earthquake. © 2015 Pearson Education, Inc.

How can tsunami waves be so deceiving? a) The trough (lowest point) may arrive first. b) They look small out at sea because of the distance to the horizon. c) The time between waves may be as long as an hour. d) They normally do not break like regular ocean waves. e) All of these are ways that tsunami waves are deceiving. © 2015 Pearson Education, Inc.

What was not a problem associated with the 2011 Japanese earthquake and tsunami? a) The small village of Fudai had built a much higher wall than people thought was necessary in the 1960 s. b) Seawalls were quickly overtopped and destroyed. c) A false sense of security was developed from the extensive seawall network. d) The earthquake was greater than they had planned for during preparations. e) Scientific evidence of the possibility of a larger earthquake/tsunami were largely ignored. © 2015 Pearson Education, Inc.