IAS General Studies Prelims Question No. 13
Interior of the earth is in a molten state. This is explained by the fact that:
1. P waves are fastest to reach a nearby seismic station
2. There is a earthquake shadow zone surrounding the antipode of the epicentre
3. Deflection of P-waves in the interior of the Earth
Select the correct option from the codes given below:
[A] Only 1 & 2
[B] Only 2 & 3
[C] Only 1 & 3
[D] 1, 2 & 3
[toggles][toggle title=”Answer”]
[B] Only 2 & 3
An earthquake is not felt in all parts of the world. In case of any earthquake, there is a shadow zone in which the earthquake is not felt. The shadow zone surrounds the antipode (diametrically opposite on the globe) of the epicentre. The shadow zone around the area antipodal to the epicentre is caused because the P- and S-waves fail to reach this area and the L-waves, if they at all reach this region, would have become extremely weak due to a long distance from the epicentre. The P-waves fail to reach this area due to deflection and the S-waves are absorbed in the interior of the earth. This indicates that the interior of the earth is in a molten state. [Geography – Surender Singh TMH)
[/toggle][/toggles]An earthquake is not felt in all parts of the world. In case of any earthquake, there is a shadow zone in which the earthquake is not felt. The shadow zone surrounds the antipode (diametrically opposite on the globe) of the epicentre. The shadow zone around the area antipodal to the epicentre is caused because the P- and S-waves fail to reach this area and the L-waves, if they at all reach this region, would have become extremely weak due to a long distance from the epicentre. The P-waves fail to reach this area due to deflection and the S-waves are absorbed in the interior of the earth. This indicates that the interior of the earth is in a molten state. [Geography – Surender Singh TMH)