Page 168 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

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ROE RR Migrated time and migrated depth sections in a region of drastic difference in layer 6.15 FIGURE s K. Larner, B. Gibson, and velocity. From R. Chambers, Imaging beneath complex structure, American AAPG with permission of the = ae ae 26-39, © 1983, Redrawn i oo ee Opahone att Ue SEONG IRA -
Effects of vertical changes (a), having in upper layer, two-way travel dips of time the anti- with raypath event in primary
Profiles (b). Proper depth conversion the true thickness. actually encounter anticline unmigrated outside separating 6.18b). The the 6.18c). raypath-bending of faulting of hori- migration, distortion takes lower shown is advantages Only
Reflection 6.14 velocity. The middle layer twice the velocity of the occupies only half the basement they when the below an from interface (V,; Fig. below interface (Fig. the standard shows still which the that effects following 1)
Seismic FIGURE in in time (c) restores the (Fig. 6.17b). Law, placed on originating the cross layer events for interpretation a conversion migration, notice bending the problems.
Of (uy) yideq (s) ew JPABLL (um) yideq that wedge Snell’s effect) they velocity horizontal horizontal account of results 6.19d; raypath have potential
Interpretation > V, Ss 2 . 9 42.0 S 2 . 38 shows accretionary to interface horizontal bending 6.18)*Rays (Fig. when higher the the from area, crossing sufficiently erroneous the shows A depth bent. sophisticated Fig. in section faulted. be not and sections time and
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Tectonic V, conversion the according A (raypath events pullup downward from (V,) reflections larger not will to leading 6.19b not more the may it 3 and velocity, migrated techniques
And Change Depth beneath (refract), 3.22). velocity refract a over routines Fig. are raypaths 6.19c). A 2, 1, geometric, and
Structural Velocity 1.0s te=0.5s trench. the region direction (Fig. obliquely overlapping to addition anticline lower velocity incidence spread migration 6.18d), sometimes continuous. that (Fig. event account, produces continuous, suggesting Effects produces unmigrated understanding interpretation
6 t;= filling trench Bending change shows in the of with normal thus Most (Fig. are that assumption lower into of that The
Chapter Model of Vertical Section Section water the from Raypath Rays interfaces 6.8 Fig. section, bounds layer the resulting, are cline effect zons the of the bending more is Combination model A 6.20. Fig. for
150 Time Depth 3.
a) b) 5 c)