Page 369 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

351

Exercises

Selected m m/s m/s m/s m/s m/s E-W E-W

to 20,000 2500 1250 3000 2503 2512 on not Z or N-S on s mGal mGal mGal
Answers B) N-S; not —85.9 mGal = —171.8 mGal —343.6 mGal +85.9 mGal +343.6 mGal
(below 57! m7?37! s™! +0.248 —0.183 —0.068 m m/s m/s m/s m/s m/s to south; on not Z and 0 —257.7 0 +171.8 +257.7

km m7? 10°kg m=? s*! m=? = = = 2,000 2500 1250 3000 2795 3536 E~W; il = = = = = = = = +111.9 mGal
0.94 10°kg 10°kg 10°kg RC RC RC Z down: N-S 6:04:00:0n Ags,(water) = Ag,,(water) Ag,,(water) Age,(water) Agra(water)
km/s direction) = zy X 5.50 x 9.12 X 6.30 x 5.50 0.800 s; 0.826 s; s; 0.859 Exist 6:02:05; 6:03:52: on p than Gal Ag,,(mantle) Ag,,(mantle) Ag-,(mantle) Ag,,(mantle) Ag,,(mantle) =
6.8 = = = = = = = m/s m/s % 6:03:28 ~ 0 mGal km
= BtoA (below A); Shale: 1 1 1 Shale: T Interface: Interface:T Interface:T Om 2500 1250 Doesn’t co ~ = = onset: onset: more = p 980,900.91 150.27 mGal 54.58 mGal —33.24 mGal —87.84 32.07 = km: km: Ag(topo)
V, = 3.9km/s;V, (in =14.5° km 2.08 Sandstone: Tight Sandstone:1 Porous 1" 2" 3 P P m 2438 10.000 575.000 onset: P-wave onset: S-wave wave wave Rayleigh increase and k decrease k and and increases #0 tou ot = Age, = Ag, h,(continent) X=-c:; X=-2.5km: X=0: X=+2.5km: +0: X= x KK i] 0: na "oof K +o: Maximum i)
+22.54
—22.54
=o:
“28
i
ke
a) a b) 2%, = c) a) c) Direct Rayleigh Refracted Primary P Multiple P = h a) = = b) dé) e) Love f) g) i) » ii) p iii) p iv) a iv) v) => a) i) b) a)
4-5 5-2 7-1 7-2 7-5 8-7

of therefore are to elements the waves mantle the higher critical
importance is solution the relates heavy than p) Seismic is more incompress- is mesosphere mesosphere. the because and velocity in result low occurs gravity

solutions. The alone solution A to Jead that steps the problem how in higher and oxygen) (higher denser is mantle down. waves the mantle the because crust. the the while than denser is core mesosphere the in than 0). = (p m 25.000 m/s 2000 m/s 4000 m/s 2025 higher is granite materials Both density. a high, while .

Selected specific have that solution. the to and assumptions essential; illustrate and (silcon The crust. slow to tends crust the in than ») nickel) (iron, outer silicate). The core outer the rigidity has no and 2.500 m m/s 2000 Exist Doesn't m/s 3774 strata, lower and agravity produces < 4.1 s t, = 5.8s = 8.0s =

D exercises get to the are sketches W-N50° W silica the than actually than more rigid (higher elements in slower p) (higher Exist sedimentary velocity intrusion km/s km/s; km/s;t, km/s; 1,

1.5
DIX to some to taken steps the response: cases, all earth. N45° cm/year: cm/year in lower is magnesium) density higher mantle the and k) heavy is core (iron-magnesium travel waves is denser Om 2000 m/s Doesn‘t * surrounding higher is salt granite the dome. 6km/s = km:V, 185km km Ht 3.3 V, = Refraction: 5.3 Refraction: V, = 8.3 = V, Refraction: km km
V, =
Direct:
t=7.7s
PE'N Answers Exercises answers are is exercise appropriate an In required. the understanding 10-11 a) 4.5-5.5 b) mantic The a) and (iron the crust: travel faster in (higher ible outer The d) material Seismic core outer P Direct P Refracted P Reflected to Compared while density, refraction, but salt a over h=35 a) V,=8km/s b) X.=79km h) Hou ui z 370 b) 1“ 2™
X, =

i)
j)
AP Below each not also 2-7 4-1 350