The use of "seismic air guns" to determine how much oil and gas lies beneath a vast swath of the ocean floor off the southeast coast of the United States is provoking an early skirmish in a battle over oil drilling that is still years away.
The devices, towed behind vessels that trace grids on the ocean surface, emit blasts of compressed air that both energy companies and conservationists acknowledge are at least as loud as a roaring jet engine. They also agree that to use the reflected sound to map what lies deep beneath the ocean floor, those pulses must be emitted every 10 or 15 seconds, for days, weeks and possibly months at a time.
That's about where the accord ends.