Q. A seismic shadow zone is an area of the Earth's surface where:

1. seismographs cannot detect an earthquake  
2. neither the P-waves nor the S-waves reach the surface

Which of the above statements is/are correct?
Answer: Both 1 & 2
Notes: Both are correct statements
The shadow zone is an area on the earth’s surface in between 104 degrees to 140 degrees from the epicentre where neither the primary waves nor the secondary waves reach the surface. The L-waves, which are surface waves, reach the shadow zone in some cases, but are so weak, that it becomes almost impossible to detect them. The P-waves fail to reach this area due to deflection and the S-waves are absorbed in the interior of the earth.

This question is part of UPSC Daily 20 MCQ Series Course on GKToday Android app.