Good Vibrations

Seismic blasting? Explosion bombs? Or something far more mundane? I explain how the injection of compressed air into the ocean from remotely-controlled devices to produce acoustic pressure waves is a relatively benign process. Farts from several small mechanical robots. Seismic exploration can in fact be directly compared to ultrasound investigations of the human body: incredibly sensitive instruments record weak vibrations reflected from within the target medium and are used to produce remarkably informative images. The Perils of Misplaced Language A prominent Australian mining executive recently referred to the compressed air released during marine seismic surveys as "explosion bombs". Although his statement was gamesmanship being used to attack an industry rival, the comment nevertheless had some impact in the mainstream media. In a typical 'marine seismic survey' a small ship tows a vast amount of sensitive listening devices close to the surface of the ocean. In t