Paper Summary
Exploration in complex geological settings, particularly beneath salt or basalt, has long recognized the need for lower frequencies. This need arises from two factors: first, the desire to extend the low-end bandwidth for FWI velocity updates, which helps mitigate the dependence of inversion results on inaccurate starting velocity models; and second, the fact that very low frequencies (<10 Hz) exhibit much better signal penetration, essential for reaching the long offsets required for resolving deep-target velocity sensitivity.
To address this need, a new generation of low-frequency pneumatic sources has been introduced to the marine seismic market. These sources share a common design principle: a significantly increased air chamber volume, which results in lower resonance frequencies of bubble oscillation. This oscillation is the primary generator of low-frequency energy in pneumatic marine seismic sources. Unlike traditional marine source arrays, these new sources operate as single devices and behave like point sources at frequencies typically observed in seismic exploration.
We will demonstrate that large-volume single sources provide the added benefit of significantly
reducing high-frequency sound emissions into the underwater environment, which could be
particularly important for mitigating the environmental impact of seismic activities on marine life.