With reference to earthquake waves, consider the following statements: 1. Body waves are generated due to the release of energy at the focus. 2. Surface waves move faster than body waves and are the first to be recorded on a seismograph. 3. Surface waves are considered to be the most damaging waves. Which of the statements given above is/are correct?

The correct option is 1 and 3 only. Explanation Earthquake waves are fundamentally classified into two categories: Body waves and Surface waves. These waves differ in their origin, velocity, and propagation characteristics. - Statement 1 is Correct: Body waves are generated due to the release of energy at the focus (hypocenter). These waves travel through the interior of the Earth, interacting with surface rocks to generate a new set of waves called surface waves. Body waves are further divided into P-waves and S-waves. - Statement 2 is Incorrect: Body waves are faster than surface waves. Among body waves, P-waves move the fastest and are the first to arrive at the surface. Surface waves are the slowest among earthquake waves and are the last to be recorded on a seismograph. - Statement 3 is Correct: Although surface waves are the slowest, they are the most destructive. They cause displacement of rocks and structural collapse because they possess high amplitude and involve complex horizontal and vertical ground motion. Consequently, they are considered the most damaging waves. Key Takeaway: There is an inverse relationship between the speed and destructiveness of earthquake waves; P-waves are the fastest but least damaging, while Surface waves are the slowest but most catastrophic.

With reference to earthquake waves,… - NCERT Class 11 Geography MCQ

NCERT Class 11 Geography — Chapter 2: Interior of the earth

mcqmedium

With reference to earthquake waves, consider the following statements:

Body waves are generated due to the release of energy at the focus.
Surface waves move faster than body waves and are the first to be recorded on a seismograph.
Surface waves are considered to be the most damaging waves.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 20

Options

A1 and 2 only
B1, 2 and 3
C2 only
D1 and 3 only

Did you get this right?

Solution

The correct option is 1 and 3 only.

Explanation

Earthquake waves are fundamentally classified into two categories: Body waves and Surface waves. These waves differ in their origin, velocity, and propagation characteristics.

Statement 1 is Correct: Body waves are generated due to the release of energy at the focus (hypocenter). These waves travel through the interior of the Earth, interacting with surface rocks to generate a new set of waves called surface waves. Body waves are further divided into P-waves and S-waves.
Statement 2 is Incorrect: Body waves are faster than surface waves. Among body waves, P-waves move the fastest and are the first to arrive at the surface. Surface waves are the slowest among earthquake waves and are the last to be recorded on a seismograph.
Statement 3 is Correct: Although surface waves are the slowest, they are the most destructive. They cause displacement of rocks and structural collapse because they possess high amplitude and involve complex horizontal and vertical ground motion. Consequently, they are considered the most damaging waves.

Key Takeaway: There is an inverse relationship between the speed and destructiveness of earthquake waves; P-waves are the fastest but least damaging, while Surface waves are the slowest but most catastrophic.

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