Page 368 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

351
Exercises
Selected
m/s
m/s
m/s
m/s
m/s
E-W
m
E-W
20,000
2500
3000
2503
2512
1250
s
on
on
Z or N-S
to
mGal
not
N-S; not
+85.9 mGal
Answers
B)
to south;
+257.7
(below
on
m/s
m/s
—0.183
+0.248
—0.068
m/s
m/s
m/s
s™!
57!
m7?37!
10°kg m=? s*!
m
Z and
not
2,000
m=?
m7?
0
0
3536
2795
2500
1250
3000
6:02:05;
Z down: N-S
=
=
=
Ags,(water) =
E~W;
km
il
=
=
=
Ag,,(mantle)
10°kg
10°kg
10°kg
Ag,,(mantle)
Ag,,(mantle)
6:04:00:0n
0.94
RC
RC
RC
direction)
6:03:52: on
0.800 s;
0.826 s;
s;
=
km/s
Gal
x
p
X
x
X
0.859
Exist
zy
than
5.50
6.30
5.50
9.12
mGal
—33.24 mGal
km
150.27 mGal
m/s
m/s
6:03:28
(below A);
~
54.58 mGal
6.8
980,900.91
Om
more
=
=
=
Doesn’t
32.07
%
=
=
=
=
co
0
km:
onset:
BtoA
km:
2500
1250
=
=
T
Interface:
=
Interface:T
—87.84
Interface:T
Sandstone:1
1
Sandstone:
Shale:
1
1
Shale:
onset:
V, = 3.9km/s;V,
p
—22.54
+22.54
decrease
increase
~
=
=
and
wave
=o:
(in
onset:
h,(continent)
onset:
km
X=-c:;
=
=
ot
575.000
tou
=14.5°
increases
wave
“28
Ag,
Age,
2.08
Rayleigh
i
P
m
2"
k
3
1"
P-wave
S-wave
Multiple
#0
Porous
10.000
and k
Primary
Tight
Refracted
and
ke
2438
Rayleigh
P
Love
2%, =
iv)
v)
i)
Direct
a
=
»
p
p
=
=>
b)
f)
ii)
e)
g)
iv)
iii)
=
c)
b)
a)
dé)
c)
a)
a)
a
i)
a)
b)
h
P
P
7-5
7-1
5-2
7-2
4-5
—85.9 mGal = Ag,,(water) X=-2.5km: = —171.8 mGal Ag,,(water) X=0: mGal —257.7 = Age,(water) X=+2.5km: —343.6 mGal = Agra(water) +0: X= x KK i] mGal +171.8 = Ag-,(mantle) 0: na "oof K +343.6 mGal = Ag,,(mantle) +o: +111.9 mGal = Ag(topo) Maximum i) a) 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,
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
1.5
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