As powerful as air gun, Distributed Seismic Source™ eliminates explosive blasting that has been blamed for harming whales, porpoises, and other marine life. DSS puts array of powerful sources downhole, each providing more than 2,400 lb of force at 200 Hz. Placing sources beneath near-surface weathering layer eliminates 95% or more of attenuation seen by surfaces sources. System can change how offshore seismic surveys are performed for exploration and production of oil and gas.