530 



SEISMIC METHODS 



[Chap. 9 



(Fig. 9-66, AB = 2200 m) 



Up-Dip Profile 



vi = 1800 m. sec"' 



I'iu =3415 msec" 



V3k = 6530 m • see" 



xiiu = 843 m 



, . _ . , from A 

 Xi3u = 1174 m^ 



The calculation proceeds as follows : 



Down-Dip Profile 



vi = 1800 m. sec'' 

 V2d = 2700 m. sec"' 

 Vsd = 3495 m • sec"' 

 x„. = 275 m| f^^_^ ^ 



XiM = 677 mj 



(1) 1^ = [sin ii - <^] = i^; = 0.527 = sin 31'' 50' 

 V2u 3415 



^ = [sin z\ + ^] = 1?5? = 0.667 = sin 41° 50' 



= 5^ 



ii = 36" 50' 



(2) 



V2 = 



Vi 



1800 nnnn -1 



= 3000 m-sec 



(3) //i„ = 



sin ii 0.6 



xizjl - sin (ii - <p)] _ 843(1 - sin 31°50') _ 



2 cos t'l cos ^ 



2.0.8-0.996 



= 250 m 



^ a:i2d[l - sin (ti + <p)] ^ 275(1 - sin 45°50') ^ ^^ ^ 

 2cosziCosv' 2.0.8.0.996 



m 



(4) 



^ = sin (^ - ^) = ^1^-^ = 0.2756 = sin 16*= 

 V3„ 6530 



^ = sin (a + ^) = ^ = 0.5150 = sin 31= 

 V3d 3495 



^ = 21' 

 a = 26' 



(5) '4^ = sin [^2 + (^ - <p)] = ^ = 0.729 = sin46°50'; >p - <p = 5' 

 sm ti U.D 



l|^ = sin [i, - (^ - ^)] = ^4?^ = 0.598 = sin36°50'; i^ = 41''50' 



smzi 



(6) xj^ = 10° 



(7) V3 = .^^ 



sin 12 0.666 



0.6 



3000 > _^^ -1 



= 4500 m.sec 



