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143 of the is equivalent can its from as diffrac: the * of collapses point- 6.8). the that to orientation

Profiles Seismic expression sphere diffraction, producing a subsurface reflections known depth the Migration of a that (Fig. point so extending and

Reflection 6.7 top of a very small source hyperbolic pattern. the in is point on to similar considered a distances, and events proper size

on FIGURE point a point A incidence such a pattern, depending point. the large from its
Structures OUIL] JOABLL OUI] JOABLL normal from above anticline is be to anticline horizontal to

of yideq yideq ABM-OM], ABM-OML Diffraction) of energy material an of large too the across anticline

Appearance sphere, leading to hyperbolic the top the sphere encounter cutting the collapses

Model (Point-Source small Reflection a has event of velocity point. from the with out, spread 6.9). (Fig.

Section
Diffraction @ Raypaths Section ee Migrates Point Small Sphere very a of as 6.7). (Fig. unmigrated seismic a to back Reflection but diffraction, raypaths incidence is event Migration times. events other

Time
Source Incidence Hyperbolic hs Time Diffraction to Back Very thought surface upper tion. The the and hyperbola Anticline source Normal unmigrated travel to relative

Point Normal Unmigrated Diffraction Migrated be point the large

&) b) c)
d)

Profiles (semicircle arcs swinging by defined relationships of point each migrated the 3) points; is event make to inci- normal its from cuts it and has event shortens, steepens, interfaces. Seismic expression of line) connecting interfaces (dashed lines).

Reflection hemisphere 6.5a). as is segment Notice 1) 6.5c): the of point migrated unmigrated tends thus shorter. The downdip be, should the where horizontal (solid

Seismic a (Fig. envisioned the 6.5b). (Fig. the 4) profile become Interfaces appears it than gap a touch. Migration the 6.6 dipping interface two horizontal

Of on event be can of position (Fig. arcs event corresponding corresponding event; seismic and event time is there FIGURE ay
Interpretation anywhere from the through segment migrated of the the of the than migrated a Migrating steepen, Horizontal dipping a in deeper is direction, should it belongs, connecting yideq yjdeq OUI] JOABLL OUI] JOABLL
ACM-OML
ABf-OM 1

Tectonic been drawn reflection event. The each to positions from downdip deeper are the than event. updip, shallow, Two Connecting that illustrate event updip event it where anaziisieestaal Vp

And have structure) linear the tangent migrated is points steep 6.6 unmigrated the In horizontal to updip
Structural trace could a of along running and event unmigrated less is event migrated move Interface Fig. in events. the from event Model Section

seismic two-dimensional Migration points segment unmigrated the segments raypaths position. The horizontal the Interface Time
6 unmigrated 2) than Dipping away moves
Chapter the on for through line the the of the event; unmigrated longer reflecting dence actual across moved and Dipping Vy Normal Unmigrated

142 a) b) c)