1.
What can cause a Tsunami?
Correct Answer
D. All the above
Explanation
Tsunamis can be caused by a variety of geological events that displace large volumes of water. These include landslides, where massive amounts of earth moving into a body of water can create a tsunami; underwater earthquakes, which are the most common cause, where the sea floor abruptly deforms and vertically displaces the overlying water; and volcanic eruptions, which can either displace water through the collapse of volcanic material into the sea or by the force of the eruption itself. Each of these events has the potential to generate waves that can travel across oceans at high speeds and cause devastating impacts when they reach coastlines.
2.
Do all undersea earthquakes trigger a tsunami?
Correct Answer
B. No
Explanation
Not all undersea earthquakes trigger a tsunami. While undersea earthquakes can generate tsunamis, several factors determine whether a tsunami will occur. The magnitude and depth of the earthquake, as well as the type of fault movement, are crucial in determining if a tsunami will be generated. Additionally, the proximity of the earthquake to coastal areas and the shape of the coastline also play a role. Therefore, it is incorrect to assume that all undersea earthquakes will result in a tsunami.
3.
What does the word "tsunami" mean in Japanese?
Correct Answer
B. Harbour wave
Explanation
The word "tsunami" in Japanese refers to a "harbour wave". This term is used to describe a series of large ocean waves that are caused by underwater earthquakes or volcanic eruptions. These waves can travel at high speeds and cause significant destruction when they reach coastal areas. The term "harbour wave" is an accurate translation of the word "tsunami" and reflects the nature of these powerful and devastating waves.
4.
Witnesses have said that an approaching tsunami sounds like what?
Correct Answer
B. A Freight train
Explanation
An approaching tsunami sounds like a freight train because witnesses have reported that the noise generated by the powerful and rapidly approaching waves resembles the sound of a freight train. This comparison is often used to describe the loud and thunderous noise that accompanies a tsunami, indicating its force and intensity.
5.
What is the most active tsunami area?
Correct Answer
A. Pacific Ocean
Explanation
The Pacific Ocean is the most active tsunami area because it is surrounded by the "Ring of Fire," a region known for its frequent seismic activity and volcanic eruptions. This makes the Pacific Ocean prone to earthquakes and underwater landslides, which can trigger tsunamis. Additionally, the Pacific Ocean is the largest ocean in the world, covering a vast area and exposing more coastlines to potential tsunami threats.
6.
What is the deadliest tsunami ever recorded?
Correct Answer
D. The 2004 Indian Ocean tsunami
Explanation
The 2004 Indian Ocean tsunami is considered the deadliest tsunami ever recorded because it caused widespread devastation and loss of life across several countries. Triggered by a massive undersea earthquake off the coast of Sumatra, Indonesia, the tsunami resulted in the deaths of approximately 230,000 people in 14 countries. The waves reached heights of up to 100 feet and traveled as far as 3,000 miles, causing destruction along the coasts of Thailand, Sri Lanka, India, and Indonesia, among others. The scale of the disaster and its impact on human lives make it the deadliest tsunami in history.
7.
How fast can a tsunami travel?
Correct Answer
C. Up to 500 miles an hour (800 kilometers an hour
Explanation
Tsunamis can travel at speeds of up to 500 miles an hour (800 kilometers an hour). Tsunamis are caused by underwater earthquakes, volcanic eruptions, or landslides, and they generate powerful waves that can travel across the ocean at high speeds. The speed at which a tsunami travels depends on various factors, including the depth of the water and the distance from the source of the disturbance. As tsunamis approach shallow water near the coast, their speed decreases, but they can still cause significant damage due to their immense power.
8.
Can you detect a tsunami in the open ocean?
Correct Answer
B. No
Explanation
Tsunamis cannot be detected in the open ocean. Unlike regular ocean waves, tsunamis have long wavelengths and low amplitudes, making them difficult to detect from ships or buoys. They only become noticeable when they reach shallow water near the coastline, causing a rapid rise in water level. Therefore, the correct answer is no, tsunamis cannot be detected in the open ocean.
9.
Where was the largest tsunami in history recorded?
Correct Answer
C. Alaska
Explanation
The "Lituya Bay Mega-Tsunami," which struck on July 9, 1958, in Lituya Bay, Alaska, USA, stands as the most extensive and destructive tsunami ever documented.
10.
What is frequently a warning sign of an impending tsunami?
Correct Answer
C. Seawater suddenly retreats from the shore
Explanation
Seawater suddenly retreating from the shore is frequently a warning sign of an impending tsunami. This occurs because the approaching tsunami wave pulls back the water from the coastline, creating a noticeable and abnormal recession of the sea. This phenomenon is often accompanied by a loud noise and the exposure of the seabed, indicating that a tsunami is approaching and the water will soon rush back towards the shore with great force.