SYNTHETIC SEISMOGRAMS FROM VIBRACORES - A CASE-STUDY IN CORRELATING THE LATE QUATERNARY SEISMIC STRATIGRAPHY OF THE NEW-JERSEY INNER CONTINENTAL-SHELF

A new technique, using empirical relationships between median grain si ze and density and velocity to calculate proxy values for density and velocity, avoids many of the problems associated with the use of well logs and shipboard measurements to construct synthetic seismograms, Th is method was used to groundtruth and correlate across both analog and digital shallow high-resolution seismic data on the New Jersey shelf Sampling dry vibracores to determine median grain size eliminates the detrimental effects that coring disturbances and preservation variable s have on the sediment and water content of the core. The link between seismic response to lithology and bed spacing is more exact, The exac t frequency of the field seismic data can be realistically simulated b y a 10-20 cm sampling interval of the vibracores, The estimate of the percentage error inherent in this technique, 12% for acoustic impedanc e and 24% for reflection amplitude, is calculated to one standard devi ation and is within a reasonable limit for such a procedure. The synth etic seismograms of two cores, 4-6 m long, were used to correlate spec ific sedimentary deposits to specific seismic reflection responses, Be cause this technique is applicable to unconsolidated sediments, it is ideal for upper Pleistocene and Holocene strata.