Waves Quiz
The most influential agent that changes the shape of the coast is ______. high tide hurricanes and storm surges prevailing winds freezing and thawing of coastal cliffs wave action
wave action
When waves shoal, all of the following occur EXCEPT ______. wave period decreases wavelength shortens wave height increases wave speed decreases the wave steepens
wave period decreases
You are asked to devise a system that determines when waves become unstable. Which of the following parameters would you monitor? water depth and wave height wavelength and wave height wave dispersion and wave speed wave speed and wave energy water depth and wave prolongation
wavelength and wave height
List the following waves in order of SHORTEST to LONGEST wavelength. Capillary waves Wind Waves Tides Tsunami
Capillary waves Wind Waves Tsunami Tide
Which of the following statements is FALSE? Rogue waves are giant, short-lived waves. Rogue waves have struck shorelines, sweeping people off the beach. Where large wind waves are common, rogue waves may be expected. Constructive interference produces a set of rogue waves that have uniform height and wavelength. Rogue waves transport energy.
Constructive interference produces a set of rogue waves that have uniform height and wavelength.
Refer to figure below. Imagine that you live in a house at the beach where longshore drift is from WEST to EAST. Your neighbour to the east builds a BREAKWATER, as shown below. This causes the sand ______. longshore drift to move seaward of the breakwater and get deposited in an offshore sandbar to be carried around the breakwater and continue its journey to the EAST in front of your neighbour's house to build up gradually to be deposited in front of a different neighbour's house to your west in front of your house to erode completely
in front of your neighbour's house to build up gradually
Which of the following is FALSE about the Pacific Tsunami Warning Center (PTWC)? The PTWC ______. depends on the assistance of government agencies to alert and evacuate coastal communities in the event of a tsunami issued a tsunami warning to Indonesia on 26 December 2004 uses data from DART™ to detect tsunami as small as 1 cm is directly in charge of alerting populations in the Pacific Northwest for regional tsunami events needs about one hour to gather information before they know enough to issue a tsunami warning
is directly in charge of alerting populations in the Pacific Northwest for regional tsunami events
A seiche generated by a landslide into Lake Ontario would have a resonance period ______ a seiche in your friend's hot tub. shorter than longer than the same length as less regular than more regular than
longer than
Following a tsunami warning after an earthquake off the coast of Alaska, one of the worst places to be is ______. on a submarine on the surface of the Pacific Ocean, where the water is at least 3,500 meters deep in a park located beyond the tsunami inundation zone on a sailboat off the coast of Halifax, NS lying on a beach in Hilo Bay, Hawaii on the 5th floor (or higher) of a reinforced concrete building on a beach in Japan
lying on a beach in Hilo Bay, Hawaii
If the waves are approaching Vancouver Island from the south and the Island lies on a northwest to southeast direction, the longshore transport will be directed from ______. northwest to southeast south to north north to south southwest to northeast
southwest to northeast
When waves approach shore where the bottom is VERY STEEP, the waves will ______. reflect surge become less steep converge spill
surge
As tsunami approach shore, ______. the wave hits the coastline like a rapidly advancing tide its behavior is unaffected by the seafloor bottom topography and shoreline the crest always arrives before the trough destruction is caused only by the advance of water onto shore the highest waves always cause the most extensive damage
the wave hits the coastline like a rapidly advancing tide
A fully developed sea is when ______. a category 5 hurricane produces a Sea State of Beaufort 11 and over the wind speed is equal to the highest average for the year the fetch is infinite the wind has been blowing over a fetch of 1 km for at least 24 hours the wave speed equals the wind speed
the wave speed equals the wind speed
A fully developed sea is when ______. the wind has been blowing over a fetch of 1 km for at least 24 hours a category 5 hurricane produces a Sea State of Beaufort 11 and over the wind speed is equal to the highest average for the year the wave speed equals the wind speed the fetch is infinite
the wave speed equals the wind speed
As waves approach shallow depths, ______. they break and become surf at the same distance from shore they bend and focus their energy on headlands they move at minimum speed they flatten out and disappear they transport more energy
they bend and focus their energy on headlands
Rogue waves are best described as ______. a strong rocking motion within a harbour abrupt bulge of water driven ashore by hurricanes a single massive wave that develops and disappears in the open ocean waves rapidly approaching shallow water that grow to great heights the third highest wave in a group
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The term "tsunami" comes from the Japanese words for "harbour wave". What is the significance of harbours to these dangerous waves? Japan's coastline includes the most number of harbours in the world. Hence, these are where tsunami have been observed the most. Tsunami are typically generated in harbours, especially those in Japan. The population density around harbours is higher, thus the potential for loss of lives from tsunami is highest. Tsunami in harbours become taller and carry more energy because of constructive interference with their reflection. Ships and boats docked in harbours are safe from tsunami.
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Tsunami may be generated by the following EXCEPT ______. icebergs falling from glaciers asteroid impacts into the deep ocean volcanic eruptions on the seafloor vertical submarine fault motion a large submarine earthquake along the San Andreas Fault
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Which of the following waves is traveling the fastest? A wave with wavelength L = ______ metres, traveling through water with depth d = ______ metres. 100; 5 100; 100 200; 2 200; 5 100; 40
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Which phrase will make this sentence FALSE? "When a tsunami travels from Alaska to Hawaii ______." only energy is transported water particles at the bottom of the ocean only move back and forth the shortest waves travel the slowest the ocean floor is above the wave base the entire ocean depth is affected by the passing wave
...
The west coast of Vancouver Island is exposed to all of the following EXCEPT ______. rogue waves large, wind-driven waves seiche tsunami surf
... Seich?
A wave with a period of 100 seconds per cycle has a frequency of ______ cycles per second. 6 0.1 0.01 0.06 1
0.01
If you observe wave crests in the Pacific Ocean that are 60 meters apart and behave as deep water waves, you know that the water must be at least ______ meters deep. 90 60 15 30 5
30
Waves at the shore will start to break when the ______. LaTeX: \frac{H}{d}\approx\frac{3}{4} H d ≈ 3 4 (ratio of wave height to water depth is about 3/4) LaTeX: H=7\times L H = 7 × L (wave height is about 7 times the wavelength) wave period increases to 15 seconds LaTeX: d\approx2\times L d ≈ 2 × L (water depth is about 2 times the wavelength) crests smooth into a rounded shape
H/d=3/4
The depth below which there is essentially no water particle movement caused by the passing of a deep water wave is ______. the amplitude the orbital 100 m L ÷ 2 the wave bottom
L ÷ 2
Why are there more devastating tsunami in the Pacific than in the Atlantic? Most major tsunami in the Pacific end up hitting Hawaii where more people are likely to be near the coast. The shapes of harbors around the Pacific amplify the effects of tsunami. The Pacific is surrounded by subduction zones, which produce large earthquakes, which generate tsunami. The Atlantic is smaller, so tsunami energy dissipates more quickly. The biggest tsunami are in the Indian Ocean, not the Atlantic or Pacific.
The Pacific is surrounded by subduction zones, which produce large earthquakes, which generate tsunami.
In the middle of the Southern Ocean, waves with the greatest speed ______. have the longest wavelengths are generated by winds blowing over the shortest fetch have the shortest wavelengths are shallow water waves maintain their speed as they approach shore
have the longest wavelengths
All of the following describe a tsunami EXCEPT ______. a harbour wave, as literally translated from Japanese caused by a disturbance that rapidly displaces a large amount of ocean water a giant, long-period wave caused by seismic disturbances on the ocean floor a tidal wave a wave with a series of peaks and troughs
a tidal wave
In the open ocean, tsunami ______. are giant breaking waves that are dangerous to ships have long wavelengths of 50 to 100 meters, and are similar to wind waves cause water particles near the ocean floor to move are short-period waves, often from 10 seconds to a few minutes are towering waves of great height that travel together
cause water particles near the ocean floor to move (they are shallow waves)
In the Northern Hemisphere, in which part of the hurricane is the storm surge the MOST disastrous for the coastline? to the north of the eye of the hurricane directly under the eye of the hurricane on the right side of the hurricane (if you're facing in the direction the hurricane is traveling) to the west of the eye of the hurricane on the left side of the hurricane (if you're facing in the direction the hurricane is traveling)
on the right side of the hurricane (if you're facing in the direction the hurricane is traveling)
In the Northern Hemisphere, in which part of the hurricane is the storm surge the MOST disastrous for the coastline? to the west of the eye of the hurricane directly under the eye of the hurricane to the north of the eye of the hurricane on the left side of the hurricane (if you're facing in the direction the hurricane is traveling) on the right side of the hurricane (if you're facing in the direction the hurricane is traveling)
on the right side of the hurricane (if you're facing in the direction the hurricane is traveling)
Which statement is FALSE? At Kitsilano Beach, ______. perfect pipeline (plunging) waves does not happen because the water is cold as a wave approaches shore, the motion of water particles is affected by friction with the ocean bottom waves form whitecaps when their crests are unstable water particles move in a back-and-forth motion as a shoaling wave passes longer waves become shallow water waves farther offshore than shorter waves
perfect pipeline (plunging) waves does not happen because the water is cold
Which phrase will make this statement TRUE? "To forecast tsunami, the DART buoy system measures ______." current direction gravitational forces wind strength and speed pressure changes thermal expansion
pressure changes
When a large earthquake occurs, people want to know whether or not it generated a tsunami, and therefore whether or not evacuation is needed. What measurements can we collect with TODAY'S technology that would directly help determine whether a tsunami is on its way, before it arrives? pressure changes in the deep ocean displacement along the fault that ruptured earthquake magnitude and location sea level heights observed from airplanes sea level heights observed from ships
pressure changes in the deep ocean DART
When a tsunami hits a bay or a harbour, its effects can be AMPLIFIED by ______. destructive interference with tides resonance, if the bay or harbour is in phase with the tsunami the deepening of the bay or harbour depth the higher concentration of people and buildings along the shore dispersion of wave energy along headlands
resonance, if the bay or harbour is in phase with the tsunami
Waves are the result of energy traveling across the ocean. Ultimately, all of the following happen to that energy, EXCEPT ______. the energy reflects off coasts, creating waves traveling in the opposite direction the energy is absorbed by the coast, causing erosion friction causes the waves to slowly transform to other forms of energy waves collide with adjacent waves and their energy is lost waves grow until they break in the open ocean, causing water to move
waves collide with adjacent waves and their energy is lost
All of the following waves are restored by gravity EXCEPT ______. waves with L < 1.7 cm waves generated by earthquakes seiches rogue waves waves with steepness > 1/7
waves with L < 1.7 cm
The ocean receives a lot of energy from the Sun, much of which enters the ocean in the equatorial region. Which of the following helps to redistribute this energy over the rest of the ocean? wind earthquakes tsunami rainfall container ships
wind