Consider the following statements regarding Tsunami warning systems: 1. At the time of the 2004 Tsunami, early warning systems were operational in the Indian Ocean. 2. A three-hour notice of a potential tsunami is possible with modern systems. 3. Tsunamis are more frequent in the Pacific Ocean than in the Indian Ocean. Which of the statements given above is/are correct?

The correct option is (c) 2 and 3 only. Explanation Tsunamis are large ocean waves caused by the sudden displacement of water, usually resulting from underwater earthquakes, volcanic eruptions, or landslides. Early warning systems rely on seismic sensors and ocean buoys to detect these disturbances and alert coastal areas. Statement-wise Analysis: - Statement 1 is Incorrect: At the time of the December 2004 Tsunami, there was no operational early warning system in the Indian Ocean. While such systems existed in the Pacific Ocean, the lack of a detection and alert mechanism in the Indian Ocean contributed significantly to the high casualty count across the region. - Statement 2 is Correct: Modern Tsunami Warning Systems (such as the DART system) combine seismic data with ocean pressure sensors. Since seismic waves travel much faster than tsunami waves, and tsunamis travel at approximately 800 km/h in deep water, it is possible to provide a notice of three hours or more for distant tsunamis (teletsunamis) originating far from the coast. - Statement 3 is Correct: Tsunamis are significantly more frequent in the Pacific Ocean than in the Indian Ocean. This is because the Pacific Ocean is surrounded by the "Ring of Fire," a seismically active belt where tectonic plate subductions frequently generate major earthquakes and volcanic activity. Key Takeaway: The Indian Ocean Tsunami Warning System was established only after the 2004 disaster. The Pacific Ocean is the most tsunami-prone region globally due to the Pacific Ring of Fire.

NCERT Class 7 Geography — Chapter 1: Water

mcqmedium

Consider the following statements regarding Tsunami warning systems:

At the time of the 2004 Tsunami, early warning systems were operational in the Indian Ocean.
A three-hour notice of a potential tsunami is possible with modern systems.
Tsunamis are more frequent in the Pacific Ocean than in the Indian Ocean.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 and 2 only
B2 only
C2 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is (c) 2 and 3 only.

Explanation

Tsunamis are large ocean waves caused by the sudden displacement of water, usually resulting from underwater earthquakes, volcanic eruptions, or landslides. Early warning systems rely on seismic sensors and ocean buoys to detect these disturbances and alert coastal areas.

Statement-wise Analysis:

Statement 1 is Incorrect: At the time of the December 2004 Tsunami, there was no operational early warning system in the Indian Ocean. While such systems existed in the Pacific Ocean, the lack of a detection and alert mechanism in the Indian Ocean contributed significantly to the high casualty count across the region.
Statement 2 is Correct: Modern Tsunami Warning Systems (such as the DART system) combine seismic data with ocean pressure sensors. Since seismic waves travel much faster than tsunami waves, and tsunamis travel at approximately 800 km/h in deep water, it is possible to provide a notice of three hours or more for distant tsunamis (teletsunamis) originating far from the coast.
Statement 3 is Correct: Tsunamis are significantly more frequent in the Pacific Ocean than in the Indian Ocean. This is because the Pacific Ocean is surrounded by the "Ring of Fire," a seismically active belt where tectonic plate subductions frequently generate major earthquakes and volcanic activity.

Key Takeaway:
The Indian Ocean Tsunami Warning System was established only after the 2004 disaster. The Pacific Ocean is the most tsunami-prone region globally due to the Pacific Ring of Fire.

Your note

More from Chapter 1: Water

The process by which water continually changes its form and circulates between oceans, atmosphere, and land is best described by which of the following terms?

easy

With reference to the distribution of water on Earth, consider the following statements: 1. Groundwater has a larger volume than inland seas and salt lakes. 2. Inland seas and salt lakes contain more water than the atmosphere. 3. The volume of water in the atmosphere is greater than that in rivers. 4. Rivers hold the least volume of water among these four sources. Which of the statements given above are correct?

hard

Consider the following statements regarding the Earth's water: 1. The water cycle ensures that the water existing today is entirely different from the water that existed centuries ago. 2. The major sources of fresh water include rivers, ponds, springs, and glaciers. 3. The amount of water in the atmosphere is higher than that in fresh water lakes. Which of the statements given above is/are correct?

medium

In the context of water distribution, which of the following accounts for the largest percentage of fresh water on Earth?

medium

Consider the following statements regarding salinity: 1. Salinity is defined as the amount of salt in grams present in 1000 grams of water. 2. The average salinity of the oceans is generally 45 parts per thousand. 3. Most of the salt in the ocean is sodium chloride. Which of the statements given above is/are correct?

medium

Keep practising Chapter 1: Water

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The correct option is (c) 2 and 3 only.

Explanation

Statement-wise Analysis:

Statement 1 is Incorrect: At the time of the December 2004 Tsunami, there was no operational early warning system in the Indian Ocean. While such systems existed in the Pacific Ocean, the lack of a detection and alert mechanism in the Indian Ocean contributed significantly to the high casualty count across the region.
Statement 2 is Correct: Modern Tsunami Warning Systems (such as the DART system) combine seismic data with ocean pressure sensors. Since seismic waves travel much faster than tsunami waves, and tsunamis travel at approximately 800 km/h in deep water, it is possible to provide a notice of three hours or more for distant tsunamis (teletsunamis) originating far from the coast.
Statement 3 is Correct: Tsunamis are significantly more frequent in the Pacific Ocean than in the Indian Ocean. This is because the Pacific Ocean is surrounded by the "Ring of Fire," a seismically active belt where tectonic plate subductions frequently generate major earthquakes and volcanic activity.

Key Takeaway:
The Indian Ocean Tsunami Warning System was established only after the 2004 disaster. The Pacific Ocean is the most tsunami-prone region globally due to the Pacific Ring of Fire.