Page 89 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

raypaths and (1,2, and 3) discussed through of chemical through mesosphere composi- composi- the athletic at stadium. the type other
71 and the com- S outer types

Exercises Selected trave]-time graph illustrating apparent composition than mantle terms slower of chemical the in of chemical the outer core than in of chemical in not but outer core. the the illustrate simulate

3.35 velocity situations chemical the travel terms faster terms in 1990’s. Spectators and to
FIGURE text. in of through asthenosphere in travel terms in inner core Earth, describe make
terms in mantle travel faster the waves seismic why lower lithosphere. the mesosphere in from waves seismic the outer core in why seismic waves travel slower in inner core the the travel in the inner core than early and 1980’s sat down, making “THE WAVE” propagate around by “THE WAVE.” could people the
Vag=@ Vo = Vp V; Vig = Large = the from differ crust the does waves seismic why Explain crust. lower lithosphere differ from the does Explain density? and composition the through than asthenosphere does the asthenosphere differ why Explain density? and asthenosphere. the in from mesosphere differ the does Explain density? and mesosphere. from

Reflected:
= Xer=
1)X=0=

2) X

3) X How a) density? the How b) »» How c) position than = How d tion the How e) tion 3-4 events stood a) b)

refracted layer the on to used by determined other for Three graph. 3.35. Fig. in wave reflected infinite have refracted the to (V,). velocity the approximately waves com- that paradox. the ice for and Vg and ».) and (k

critically refracting the arrival be can be Likewise, travel-time graph The to critically tangent apparent is reflected and Fig. 3.9, suggesting equation: The to density. Explain of Vp elastic constants

for the surface of velocity refracted the for velocity: wave refracted can case, V, arrival. a on travel-time velocity. appears thus ty, and reflected therefore is ‘wave same the horizontally direct The Vj. = from proportional. positions anomalous to Earth. the

| V,/V2 V2 the at seismic the line the of apparent same 1 4 V2 Vay 1 =V_=V. 2 ap (AT/AX) critically the 4a Vv, 1 dT Wy ae 1 =V, (dT/dX) layer flat simple, refracted the for slope of the inverse and diagram apparent high has time at arriving the raypaths for refracted The curve, signifying almost travelling material. velocity apparent data points throu

V,/V2 Vv ai V,.= ap measured (Vp) as same slope the of the yields AT Slope AX 1 = Slope for relationship: ¥ r Slope 1 Slope the for (1/V,p) the is raypath the vertically up, and distance angle. travel-time ray near-surface have thus plotted density and velocity Fig. 3.9, explain in equations relating seismic velocities (Vp and Vg) following the

= the 3.33b) equation that, slope velocity from same of a of the curve velocity
Waves sin®, velocity exactly inverse (Fig. means the of almost down critical the the velocity velocity distance a wave P-wave information discuss

Seismic Law: apparent therefore the that graph travel-time same the result inverse apparent apparent are emerging straight the At at emerge on wave apparent true great shows 3.10 pressional that the Fig. 3.10. to (p)

Snell’s Notice This the the travels 2) the at Fig. implies Using in Use density
3 The is travel-time The demonstrate situations ray velocity. arrivals reflected The as observed 3-1 3-2. 3-3.
Chapter From that: so wave (V,). taking arrivals A 1) that 3) same EXERCISES

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