92. A IS a gravity station of 45° N latitude and B is another station 20 km north of A. The measie gravity value of B is 16.2 mgal larger than that at A. Then t

92. A IS a gravity station of 45° N latitude and B is another station 20 km north of A. The measie gravity value of B is 16.2 mgal larger than that at A. Then the elevation at B is (1) (3) Same as that atA 40 m lower than that at A 80 m higher than that at A 80 m lower than that at A (2) (4) 93. The longitudinal and compressional wave velocities in a rock are 6.0 km/s and 4.0 km/s respectively Its Poisson's ratio is (1) (3) 0.1 (2) (4) 0.2 Lon 0.3 0.4 The primary (P) and secondary (S) waves from a shallow focus earthquake reached a seismological observatory at 8: 30 04 Hrs and 8:31: 16 Hrs respectively. If the velocities of the P and S waves are in the ratio 1.61, then the time of occurrence of the earthquake would be (1) 8 : 27 16 Hrs (3) 94 8: 27 32 Hrs 8:28: 52 Hrs (2) (4) 8: 28 04 Hrs