Vertical resolution of a seismic survey in stratigraphic sequences less than 100 m deep in southeastern Kansas

Abstract

A 400-m long, 12‐fold high‐resolution common depth point (CDP) reflection seismic profile was acquired across shallow converging Pennsylvanian strata in the Independence area of southeastern Kansas. One of the principal objectives was to determine practical vertical resolution limits in an excellent shallow seismic‐data area with borehole control. The dominant frequency of the CDP stacked data is in excess of 150 Hz based on peak‐to‐peak measurements. Interference phenomena observed on stacked seismic data incorporated with models derived from log and drill‐hole information suggest a practical vertical resolution limit of about 7 m, or one‐third of the dominant wavelength. This practical resolution is slightly less than the predicted (theoretical) resolution limit of 5 m based on the generally accepted one‐quarter wavelength axiom. These data suggest conventional rules of thumb describing resolution potential are not accurate when reflectors on shallow, narrow bandwidth data converge rapidly across horizontal distances less than the Fresnel Zone.

Seismic reflection characteristics of naturally-induced subsidence affecting transportation

“…The reflection immediately above the salt at approximately 80 ms possesses a maximum of 10 ms of time change across a broad synclinal structure approximately 700 m in length. This 10-ms drape on the 80-ms overburden reflection is likely in response to the over 20 ms of subsidence and bed aberrations evident within the salt interval over a distance of around 400 m. Moreover, the 80-ms reflection possesses a very smooth synclinal geometry consistent with relatively small-scale brittle deformation along subresolution fault and/or fracture zones (Miller et al, 1995). Contrasting this smooth 80-ms overburden reflection with salt reflections immediately below that appear irregular-steeply dipping in some places-and that possess unequivocal brittle deformation characteristics is indicative of a transition from high energy within the salt interval to a low-energy environment in the predominantly shale overburden.…”

Portable dense geophone array for shallow and very shallow 3D seismic reflection surveying: Part 1—Data acquisition, quality control, and processing

“…During the last few decades there has been increased use of shallow seismic reflection techniques for solving near-surface problems (e.g., Birkelo et al, 1987;Hunter et al, 1989;Miller, Steeples, et al, 1989, 1990Miller and Steeples, 1991;Miller, Anderson, et al, 1995). Seismic reflections from depths of 2 m and even as shallow as 0.5 m have been reported in the literature (Baker, Schmeisneer, et al, 1999).…”

Muting the noise cone in near‐surface reflection data: An example from southeastern Kansas

“…The two dramatic features of the final stacked section (Figure 6) are the cyclicity of the reflections and noticeable reflection discontinuities/diffractions. The cyclic reflections are typical of southeastern Kansas cyclothemic deposition and are a result of the interbedded limestone and shale units in the region which have been identified by drilling (Miller et al, 1995). The discontinuities and/or associated diffractions are interpreted as faults.…”