Question

In a blind zone, the geophone cannot detect the seisdmic refraction.

(a) False

(b) True

The question was posed to me during an interview.

I'm obligated to ask this question of Geophysical Methods topic in section Stabilisation of Soils, Site Investigation and Sub – Soil Exploration of Geotechnical Engineering II

Answer 1

Right choice is (b) True

Easiest explanation: In 1968, Goodman and Karol showed that in a blind zone, the geophone cannot detect the seisdmic refraction. The blind zone occurs when a layer having a velocity lower than that of the upper layer exists.