Tsunami Quiz
Questions: 16 · 10 minutes
1. Which earthquake is generally more likely to generate a damaging tsunami?
A deep inland earthquake with no movement of the seabed
A deep earthquake beneath a continent that produces no coastal deformation
A small earthquake whose motion is entirely horizontal and does not deform the seafloor
A shallow undersea earthquake that causes substantial vertical seafloor movement
2. After coastal shaking, the sea suddenly withdraws much farther than an ordinary low tide. What is the best interpretation?
The earthquake has permanently stopped normal tides
The exposed shore is temporarily safer because water is moving away
A storm surge is developing and should be watched from the beach
It is a natural tsunami warning, so evacuate without waiting for confirmation
3. Which statement best distinguishes a tsunami from a tide?
A tsunami occurs only at high tide, while ordinary tides occur at any time
A tsunami comes from sudden water displacement, while tides mainly result from gravitational forces
A tsunami is a wind-driven wave, while tides are caused by undersea earthquakes
A tsunami affects only beaches, while tides affect only deep water
4. You are on foot beside a harbor when an official tsunami evacuation order is issued. What is the appropriate response?
Stay on the dock so rescuers can locate you easily
Leave the waterfront promptly and follow marked routes inland or uphill
Find a small boat and head out without instructions
Wait inside a parked vehicle until the first wave passes
5. What does a deep-ocean tsunami detection system use a seafloor pressure sensor to detect?
Small pressure changes produced as a tsunami passes overhead
The precise magnitude of every earthquake on nearby land
Changes in wind direction that generate coastal surf
The salt content of water entering a harbor
6. Compared with its behavior near shore, how does a tsunami usually behave in the deep ocean?
It forms a tall, steep wall of water that travels slowly
It stops interacting with the seafloor and becomes a normal wind wave
It has a small wave height, a long wavelength, and high speed
It travels as a short series of closely spaced breaking waves
7. A coastal community has no nearby hill, but it has a clearly marked tsunami vertical-evacuation structure. During a warning, what should a person do?
Remain at street level beside the structure so the route stays visible
Use the designated structure and climb to the marked evacuation level
Drive along the coast to search for a natural hill
Enter the basement because lower floors are protected from waves
8. You are near the coast when strong shaking lasts long enough to make standing difficult. What should you do once you can move?
Go to the shoreline to check whether the water is changing
Wait for a phone alert before deciding whether to leave
Shelter inside the nearest ground-floor room until officials arrive
Move immediately to high ground or inland using an evacuation route
9. A distant earthquake was not felt locally, but authorities issue a tsunami warning for your coastal area. What should you do?
Ignore it because only felt earthquakes can produce local danger
Visit the beach to look for a receding shoreline before leaving
Follow the evacuation instruction even though you felt no shaking
Wait until water enters nearby streets before moving uphill
10. What most directly controls the speed of a tsunami traveling across deep water?
The depth of the water
The air temperature above the ocean
The daily tidal stage at the nearest beach
The direction of the prevailing wind
11. Why should people remain out of an evacuated tsunami zone after the first wave arrives?
The first wave always removes every visible evacuation sign
Tsunami water remains poisonous until the next high tide
Later waves may be larger, and dangerous currents can continue for hours
After one wave, the shoreline cannot be assessed for exactly 24 hours
12. A large landslide suddenly falls into a coastal bay. Which tsunami hazard is most plausible?
Any resulting wave must cross an entire ocean before reaching shore
A wave can form only if an undersea fault also ruptures
A powerful, localized wave may arrive nearby with very little warning
The landslide can change tides but cannot displace enough water for a tsunami
13. Which tectonic setting is especially capable of producing a large earthquake-generated tsunami?
A subduction zone where one plate descends beneath another
A transform boundary where plates mainly slide horizontally past each other
A stable continental interior with no active plate boundary
A mid-ocean ridge where plates separate gradually
14. When is it appropriate to return to a coastal area evacuated because of a tsunami?
As soon as the first wave begins to recede
When authorities issue an official all-clear
At the next scheduled low tide
When other residents start driving back
15. What causes most tsunamis?
Warm ocean currents colliding with cold currents
Strong winds pushing surface water toward the coast
Daily changes in the gravitational pull that produces tides
Sudden vertical displacement of the seafloor during an undersea earthquake
16. After officials allow residents back following a tsunami, which action best addresses continuing hazards?
Avoid floodwater and unstable structures, and follow guidance about utilities and water
Enter damaged buildings quickly before aftershocks occur
Use tap water immediately if it appears clear
Walk through standing water to check whether roads remain passable