Q. Which of the following statements is/are correct regarding shadow zones of earthquakes?
Select the correct answer using the code given below:
Q. Which of the following statements is/are correct regarding shadow zones of earthquakes?
Select the correct answer using the code given below:
The correct option is C 1 and 3 only
Explanation:
Statement 1 is correct: A shadow zone is an area of the Earth's surface where seismographs do not detect any earthquake waves.
Statement 2 is incorrect: The shadow zone of the S-wave is larger than that of the P-waves.S waves cannot pass through the liquid outer core and are not detected beyond 103°. Thus, the entire zone beyond 103° is referred to as the Shadow zone of S-waves. The shadow zone of P-waves appears as a band around the earth between 105° and 145° away from the epicentre.
Statement 3 is correct: A zone between 105° and 145° from the epicentre is recognized as the shadow zone for both the wave types.
Explanation:
Statement 1 is correct: A shadow zone is an area of the Earth's surface where seismographs do not detect any earthquake waves.
Statement 2 is incorrect: The shadow zone of the S-wave is larger than that of the P-waves.S waves cannot pass through the liquid outer core and are not detected beyond 103°. Thus, the entire zone beyond 103° is referred to as the Shadow zone of S-waves. The shadow zone of P-waves appears as a band around the earth between 105° and 145° away from the epicentre.
Statement 3 is correct: A zone between 105° and 145° from the epicentre is recognized as the shadow zone for both the wave types.
