Page 172 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

155
Tectonic Settings
of
Expression
Seismic
2km
Section
Time
Unmigrated
a)
0.0 ERG Eorewe neat teats proceed = N BRAN o ot Ree x SS ee Sess Lae Se, aD S 5 Lower Event = Still Distorted Ss (Bending Accounted For) 'S 6.19 Distorted event below anticline on a) time section. The distortion may be due to.a combination unmigrated of pullup and raypath bending (Fig. 6.18b,c). b) Standard migration of (a). The continued distortion of the lower event bi may an
Ss
3
(S) OUI, JOABLL ABAA-OML v SS N FIGURE velocity
) OUILL JOABLL ABAA-OML

Deep, toward interface 61 from the 6.22c was
Profiles Raypath bending. a) to anticline Rays refract the anticline, because V, is of the portion interface directly below the 2). to point shows horizontal the to velocity pullup. accurately remove be misinterpreted. profiles with and 81 was in run verti- the struc- the of the edge synthetic seismic interpretations Fig. 6.22d
Reflection added interface (Fig. 6.8). b) crossing when is thus imaged over a broader 1] point time section addition may not taypath bending effects, leaving artifacts might that (For this same model, see Fig. 5.14). Lines side. dome the profile represents above the misses recognized. Fig. while

Seismic 6.18 FIGURE horizontal the vertical top of the greater than V,. The horizontal anticline region (from c) Unmigrated overlap in events from interface, in Migration (distortion) seismic traces in ; the from seismic a 108 line distance angle. The erroneous not is profile,

Of model on d) off to illustrates bold some dome, just oblique potentially problem that
Interpretation yideq yideq auf [OABLL ‘ OUI] JOACLL slightly dome section; sideswipe 6.22a) escarpment. The surface, the right of the an at and the of of

ABM -OMI
A BM-OML
Law)
Tectonic ‘ y j Bent Rays (Snell's Pullup iqpeeeememememem \. \ \ Effect ; the from time the (Fig. on run side the escarpment complex nature migration

And 2 2 Velocity MK, SA sermon reflected on deeper model fault a and profile crosses fault the how three-dimensional two-dimensional
Structural eos V3 Section Bending Section orm ie cinneanisitiaineaaen cette mesial Be were even distances. complicated domes seismic line the crosses shows

) ineriace Onis a f Still After Migration a of 6.22b)
' Time een ecm pment May waves event horizontal more two that the standard,
> V,
Chapter6 Model (Vz V, Unmigrated Interfaces) 1 Pad \aimaimaunmpmanp 7 Time because the show longer A vicinity of “shadow” cal Note tures. dome, and left (Fig. profile be, if could a

154 (Lower (Both Migrated Distortion Present is
a)
c) d)