Deck 7: Tsunamis

Question 1

Tsunamis are created by massive jolts of energy delivered to a mass of water by all but which of the following?

A) Earthquakes
B) Volcanoes
C) Mass movements
D) Hurricanes
E) Meteor impacts

Answer 1

D

Question 2

Most of the 245,000 deaths from the 2004 Indian Ocean tsunami occurred in _________.

A) Thailand
B) Sri Lanka
C) India
D) Indonesia
E) Bangladesh

Answer 2

D

Question 3

Tsunamis typically have _________________________ relative to wind-blown waves.

A) short periods and short wavelengths
B) short periods and long wavelengths
C) long periods and short wavelengths
D) long periods and long wavelengths
E) long periods and no measurable wavelength

Answer 3

D

Question 4

The 2004 Indian Ocean tsunami killed an estimated 245,000 people in ____ countries.

A) 5
B) 8
C) 13
D) 50
E) 60

Question 5

The great 1960 Chile earthquake (M 9.5)unleashed a tsunami that killed over 1,000 Chileans.These waves also killed 61 people in Hilo,Hawaii,14 hours after the earthquake,and another 185 people in __________,22.5 hours after the earthquake.

A) California
B) Alaska
C) Japan
D) Australia
E) the Philippines

Question 6

Which of the following best describes what happens to tsunami waves as they move from the open ocean and towards the shallow water near the shore of the coastline?

A) The waves decrease in amplitude and their velocity remains constant.
B) The waves increase in amplitude and decrease in velocity.
C) The waves maintain a constant amplitude and velocity.
D) The waves increase in amplitude and increase in velocity.

Question 7

The most common trigger for tsunami are ________.

A) earthquakes
B) volcanoes
C) mass movements
D) hurricanes
E) meteor impacts

Question 8

Wind caused waves undergo changes when they move into shallow water near the shoreline.Friction with the floor of the shallow water results in the orbits of the water molecules at the bottom of the wave to become more _________.

A) circular
B) elliptical
C) spherical
D) conical

Question 9

Tsunami is a Japanese word that means ____________________.

A) big wave
B) killer wave
C) dragon wave
D) island wave
E) harbour wave

Question 10

The 2004 Indian Ocean tsunami was generated by huge earthquake along __________ off the shore of Sumatra.

A) an oceanic transform fault
B) a seafloor spreading centre
C) a subduction zone
D) a continental rift zone
E) a hotspot island chain

Question 11

Which of the following areas has the highest occurrence of tsunami?

A) Atlantic Ocean
B) Indian Ocean
C) Pacific Ocean
D) Mediterranean Sea

Question 12

Which of the following statements best explains how earthquakes trigger tsunamis?

A) Earthquakes shift the sea floor up or downward,casing water to be displaced.
B) Earthquakes shake the water violently,causing ripples to become waves that move out rapidly in all directions.
C) Earthquakes crack the seafloor where trapped gases are released and bubble up to the surface.Large bubbles generate large waves.
D) Earthquakes crack the seafloor where trapped heat is rapidly released.This heats the ocean water causing it to expand and move like a wave.

Question 13

When wind caused waves approach the shoreline,friction causes them to slow and their wavelengths ________ resulting in waves _________.

A) decrease;growing taller
B) decrease;growing wider
C) increase;growing smaller
D) increase;growing taller

Question 14

Tsunamis arrive as a series of several waves separated by periods typically in the _________ range.

A) 1-6 seconds
B) 10-60 seconds
C) 1-6 minutes
D) 10-60 minutes
E) 1-6 hours

Question 15

Tsunami wavelengths can be as great as ______________.

A) 84 m
B) 837 m
C) 84 km
D) 837 km
E) 8,400 km

Question 16

Earthquake-related tsunamis are created by sub-sea fault movements with pronounced vertical offsets of the sea floor.Such movements occur most commonly along ____________________.

A) oceanic transform faults
B) seafloor spreading centres
C) subduction zones
D) continental rift zones
E) hotspot island chains

Question 17

Tsunami can travel at speeds of ____________ kilometres per hour.

A) 25
B) 50
C) 125
D) 550
E) 725

Question 18

The tsunami that devastated the south coast of Newfoundland in 1929 was caused by a ______________.

A) vertical rupture of the seafloor in an earthquake
B) submarine landslide caused by an earthquake
C) meteor impact
D) volcanic flank collapse in the Canary Islands

Question 19

The captain of a ship tells you that he once experienced a huge tsunami while sailing in the Pacific Ocean several hundred miles from any landmass.You decide that this sounds a little farfetched because ____________________.

A) tsunami usually occur only in the Indian Ocean and Caribbean Sea
B) tsunamis are rarely felt in deep water because they have long wavelengths and low heights
C) the ship could not have survived passing through a major tsunami in the open ocean
D) earthquakes do not occur in deep ocean waters

Question 20

Tsunamis are typically about _________ high in the open ocean,and _______ high on reaching shallow water.

A) 0.1 m;6-15m
B) 1 m;6-15m
C) 5 m;1m
D) 20 m;0.1m
E) 30 m;30m

Question 21

A ____________ is an oscillating wave that sloshes back and forth within an enclosed body of waters such as a sea,bay,lake,or swimming pool.

A) sake
B) sushi
C) serape
D) seiche
E) seraglio

Question 22

Modern tsunami warning systems make use of ___________________ to issue a "tsunami warning."

A) tidal gauges
B) seafloor pressure sensors
C) radio reports from ships in the open ocean
D) all of these are correct
E) only A and B are correct

Question 23

In 1959,the water stored behind Hegben Lake Dam in Montana began to slosh violently back and forth in a series of oscillating waves.These seiches were caused by ____________________.

A) the collapse of the dam
B) a large landslide into the lake
C) a small meteor crashing into the lake
D) a freight train plunging off a track and into the lake
E) a sudden drop of the lake bottom during an earthquake

Question 24

Prior to the 2004 event,the last major tsunami in the Indian Ocean struck in 1883 and killed about 36,000 people.This tsunami was caused by ___________________.

A) a massive undersea landslide near Sri Lanka
B) the collapse of Indonesia's Krakatau volcano
C) a large earthquake off the coast of Sumatra
D) a large earthquake off the coast of India
E) a meteor that struck in the central Indian Ocean

Question 25

In 1927 the building of a new volcanic cone began,called Anak Krakatau.Which of the following statements regarding this volcano is false?

A) It is still growing.
B) Anak Krakatau means "child of Krakatau."
C) It is a stratovolcano built above a subducting tectonic plate.
D) It is unlikely that this volcano poses a hazard to the Java Sumatra region.

Question 26

Japan had several countermeasures against tsunami in place prior to the 9.0 magnitude Tohoku earthquake of 2011.Why then was the death toll so high?

A) The earthquake destroyed the breakwater seawalls leaving the coastline vulnerable.
B) The earthquake triggered landslides destroying natural and manmade high ground so there was no place to take refuge.
C) The tsunami run-up was underestimated in many locations therefore the countermeasures were under designed and fell short of mitigating the hazard.
D) Faulty equipment design resulted in no tsunami warning being issued.

Question 27

This photograph shows:

A) river flooding
B) tornado pushing waves
C) a tsunami flows as a long-lasting sheet of water
D) a wind-blown wave rolls onto the beach
E) None of these choices are correct.

Question 28

A tsunami source was revealed by the mapping of the ocean bottom around the Hawaiian Islands.What did geologists discover on the seafloor in this area?

A) A major undersea volcano
B) A huge undersea meteor crater
C) A deep ocean trench along a subduction zone
D) A system of 25 major oceanic transform faults
E) Slumps and debris avalanches formed by at least 70 volcanic flank collapses

Question 29

Fukushima Daiichi Nuclear incident (11 March 2011)happened when:

A) a tsunami burst through the plant's defences and damaged the emergency back-up generators
B) the Tohoku earthquake damaged reactors 1 and 2
C) a landside damaged the nuclear reactor
D) a series of malfunctions affected the reactors following a severe storm.
E) none of these choices are correct

Question 30

The pressure sensors employed in tsunami warning system by the U.S.National Oceanographic and Atmospheric Administration (NOAA)exploit a fundamental feature of tsunami waves:

A) tsunami waves create a turbulence of a few tens of metres.
B) tsunami waves disturb the entire water column up to the ocean floor.
C) tsunami waves travel very slowly so pressure sensors can detect their existence in advance.
D) tsunami waves increase in height close to the shore so the pressure sensors will be activated.
E) none of these choices are correct.

Question 31

The Pacific Tsunami Warning Center (PTWC)declares a "tsunami watch" when an earthquake meeting three criteria is identified.Which of the following characteristics is not one not needed for a watch to be issued?

A) Richter magnitude of 7.0 or greater
B) Reports of shaking for more than one-minute
C) Epicenter on ocean floor
D) Hypocentre shallower than 100 kilometres

Question 32

A Grand Banks earthquake (18 November 1929)triggered the __________.

A) landslide on the Burin Peninsula which set off tsunamis toward Europe
B) submarine movement of a sediment mass which set off tsunamis
C) uplift of ocean floor which set off tsunamis
D) down-drop of ocean floor which set off tsunamis
E) ocean ridge spreading which didn't set off a tsunami.

Question 33

The 1975 tsunami at Kitimat,BC was generated by _______.

A) a flank collapse of a fjord volcano
B) an earthquake at the subduction zone at the mouth of the fjord
C) construction work in the local area triggering underwater slope failure
D) massive rock fall from the cliff face
E) the eruption of an underwater volcano

Question 34

In 1883,this volcano exploded and the resulting tsunami killed 36,000 people on Java and Sumatra.

A) Mt.St.Helens
B) Santorini
C) Krakatau
D) Vesuvius

Question 35

Before the first big wave of a tsunami,the sea may either ________ or suddenly _______.

A) churn up;withdraw
B) withdraw;rise
C) be calm;rise
D) withdraw;be calm
E) none of these choices are correct

Question 36

The English language term tidal wave is a good description of a tsunami because of their relationship to ocean tides.

Question 37

Worldwide,approximately one volcano flank collapse occurs every ______ years.

A) 10
B) 100
C) 1,000
D) 10,000
E) 100,000

Question 38

Tsunami threats in coastal British Columbia are due to _________________.

A) basin-wide tsunami generated by earthquakes in the Pacific "Ring of Fire"
B) regional tsunami from active tectonics in western North America
C) local tsunami from earthquakes offshore British Columbia
D) all of these choices are correct

Question 39

The great 1964 Alaska earthquake (M 9.2)set off a tsunami that killed 122 people along the state's sparsely populated coastline.This tsunami also killed 12 of the curious people in ___________.

A) Hawaii
B) Vancouver
C) Chili
D) California
E) Japan

Question 40

Most tsunamis are generated in the Pacific Ocean basin.

Question 41

To know whether an earthquake has triggered a tsunami,pressure sensors anchored at the sea bed relay measurement to the buoys they are attached and signals are sent by satellite to warning stations.

Question 42

There is little threat of a tsunami striking the crowded beaches of southern California.

Question 43

Tsunamis often arrive as a series of waves and the first wave is always the biggest.

Question 44

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

Question 45

While California has experienced many deadly earthquakes,it has never experienced fatalities from tsunami.

Question 46

Buoys are used to trigger tsunami warnings because the large wave passing under them lifts them much higher than wind generated waves,signaling a tsunami wave.

Question 47

The sloshing of a swimming pool during an earthquake is called a seiche.

Question 48

Project NEPTUNE was launched in 2003 as part of the Indian Ocean tsunami warning system.

Question 49

The Hawaiian Islands cover less surface area than the slumps and debris avalanches that have fallen from them.

Question 50

Before a tsunami arrives,the ocean always draws down water away from the coastline,exposing the sea floor.

Question 51

Canadian coasts have never been hit by tsunami waves.

Question 52

The Grand Banks tsunami sped up over the shallow waters of the Grand Banks trough.

Question 53

Tsunami generated from a megathrust earthquake on the Cascadia Subduction Zone could devastate the cities of Vancouver and Victoria.

Question 54

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

Question 55

Japan's 2011 tsunami was so devastating because the largest magnitude earthquake ever recorded generated it.

Question 56

There is no threat of a tsunami striking the east coast of Canada and the United States.

Question 57

Wind-caused waves are generated by the friction between wind and the water's surface.

Question 58

It is virtually impossible for ships in the open ocean to survive a passing tsunami.

Question 59

Tsunamis have long wavelengths and very short wave heights in the open ocean.

Question 60

The destructive power of a tsunami is due mostly to the great height of the wave.

Question 61

In general,any fault movements,but especially transform faults,can produce tsunamis.

Question 62

In a tsunami hazard map of Canada,Hudson Bay was labelled as a coastal area exposed to tsunamis from local sources: landslides and earthquakes.

Question 63

A knee-high tsunami wave is less dangerous than a taller wave.