Simultaneous use of Multiple Seismic Reflection Systems for High Resolution and Deep Penetration

It is possible to resolve the facies architecture of unconsolidated bottom deposits and deeper structures within underlying bedrock by using a combination of seismic reflection profiling systems. Data from Hudson Bay Canada, was concurrently collected using a Huntec DTSTM high resolution subbottom profiler, a.6 litre (40 cubic inch) airgun with single channel seismic eel, and a 16 kilojoule sparker with multichannel seismic array. No detrimental “cross talk” was recorded due to carefull adjustment of the trigger pulses and descriminate filtering for each system. Individual seismic sequences can readily be correlated between the various systems. The finest resolution (30 cm) is obtained with the Huntec DTSTM system (with a centre frequency between 3–4 kHz) [Parrott, et al 1980]. This data reveals detailed structure within the surficial sediments as well as within bedrock which is helpful in interpreting the depositional setting. The low angle bedding and regional consistency of the bedrock seismic horizons within Hudson Bay allows detailed structure revealed by the Huntec DTSTM high resolution system, to be extrapolated to depths where they are visible on the multichannel data. This approach has led to the recognition in Hudson Bay, of sedimentological structures such as fluvial point bars, reefal structures, microfaults and salt collapse structures as well as the facies architecture of the overburden above bedrock.