No abstract

The conventional seismic trace can be viewed as the real component of a complex trace which can be uniquely calculated under usual conditions. The complex trace permits the unique separation of envelope amplitude and phase information and the calculation of instantaneous frequency. These and other quantities can be displayed in a color‐encoded manner which helps an interpreter see their interrelationship and spatial changes. The significance of color patterns and their geological interpretation is illustrated by examples of seismic data from three areas.

No abstract

SHERIFF,R. E.

Geophysicists commonly recognize that a aizeable effects. Confusion sometimes results due to the failure portion of B reflector is in\,olved in causins a rc-to distinguish whether incident waves are plane or flection as seen on B seismic trace. but the areal extent spherical. An excellent explanation (but one which is usually not calculated and hence not appreciated. does not use the term "Fresnel zone") is given by Most commonly. concepts are simply transferred Hagedoorn (1954). from which Figure I is taken. from classical physical optics and called Fresnel-zone The first Fresncl zone is the portion of a reflector he of source and receiver Raypath satisfying Snell' s law Zone for first Fresnel zone trajectory Zone for second Fresnel zone trajectory Zone far third Fresnel zone trajectory FIG. 1~. Hagedoorn' ( 1954) illustration of Fresnel mnes !modified), Manuscript received by the Editor April 30, 1979; revised manuscript received August 15, 1979. * Seiscom-Delta Inc.. P. 0. Box 36928, Houston. TX 77036. ao!o-so33/sQ/asol-o968$03.~.