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Consider the following statements regarding the shadow zones of Earthquake waves: 1. The seismographs located beyond 145° from the epicentre, record the arrival of S-waves, but not that of P-waves 2. A zone between 105° and 145° from epicentre was identified as the shadow zone for both P and S types of waves. Which of the statements given above is/are correct?

Consider the following statements regarding the shadow zones of Earthquake waves: 1. The seismographs located beyond 145° from the epicentre, record the arrival of S-waves, but not that of P-waves 2. A zone between 105° and 145° from epicentre was identified as the shadow zone for both P and S types of waves. Which of the statements given above is/are correct? Correct Answer 2 only

The correct answer is 2 only.

Key Points

  • Earthquake waves get recorded in seismographs located at far off locations.
    • However, there exist some specific areas where the waves are not reported. Such a zone is called the ‘shadow zone’.

Important Points

  • It was observed that seismographs located at any distance within 105° from the epicentre, recorded the arrival of both P and S-waves.
  • However, the seismographs located beyond 145° from the epicentre, record the arrival of P-waves, but not that of S-waves. Hence statement 1 is not correct.
  • Thus, a zone between 105° and 145° from epicentre was identified as the shadow zone for both the types of waves. Hence statement 2 is correct.
  • The entire zone beyond 105° does not receive S-waves.
  • The shadow zone of S-wave is much larger than that of the P-waves.

Related Questions

With reference to an earthquake consider the following statements. 1. The point where the energy of an earthquake is released is called the hypocentre. 2. The point on the surface, nearest to the focus of the earthquake, is called epicentre. 3. Epicentre is a point directly below the focus of an earthquake. Which of the statements given above is / are correct?
Which of the following is/are correct regarding Earthquake? (a) The point where the accumulated stress gets released within the earth's crust is called Epicentre. (b) Isoseismal line is an imaginary line drawn on the map, connecting the places of the uniform intensity of an earthquake. (c) The entire zone beyond 105° does not receive S-waves.
With reference to earthquakes, which of the following statements are correct? 1. Earthquakes largely occur along the converging plate boundaries. 2. Point of origin of the earthquake in the lithosphere is known as focus/Hypocentre. 3. The intensity of the earthquake decreases with distance from the epicentre. 4. The epicentre of the earthquake always remains over continents only. Select the correct answer using the code given below.
Which of the following sequence of Heat zones is/are correctly placed? A) Torrid zone, South temperate zone and Frigid zone. B) Torrid zone, North temperate zone and Frigid zone. C) South temperate zone, torrid zone and Frigid zone. Select the correct answer given below.
Which of the statements given above are correct?
1. P - waves are the first seismic waves to reach a place
2. S - waves travel only through liquids
3. Arrival time of P and S - waves is used to locate the epicentre
4. Richter scale is a logarithmic scale
With reference to the interior of the earth consider the following statements. 1] All natural earthquakes take place in the lithosphere. 2] The lithosphere refers to the portion of depth up to 200 km from the surface of the earth. 3] Earthquake waves are basically of four types — body waves, surface waves, rolling waves and shock waves. Which of the statements given above is / are correct?
With reference to earthquakes, which of the following statements are correct? A. Earthquakes largely occur along the converging plate boundaries. B. Point of origin of earthquake in lithosphere is known as focus/hypocenter. C. Intensity of earthquake decreases with distance from the epicenter. D. Epicentre of earthquake always remains over continents only. Select the correct answer using the code given below.
Which of the following is/are matched correctly?
1. Earthquake's origin - seismic focus
2. Epicentre - point on earth's surface directly above seismic focus
3. S waves - similar to sound waves
4. Richter scale - severity of earthquake
Consider the following statements:
1. The words in section 145 are mandatory
2. The words in section 145 are discretionary
3. The proceedings under section 107 can be converted under section 145
4. The proceedings under section 107 cannot be converted under section 145.
Which of the statements given above are correct?
With reference to the interior of the earth consider the following statements. 1] Body waves are generated due to the release of energy at the focus. 2] Denser the material, the lower is the velocity of the Earthquake waves. 3] There are two types of body waves. They are called P and S-waves. Which of the statements given above is / are correct?