During the month of August, 1994, I travelled on a research vessel called the R/V Ewing to collect reflection seismic data in the Bering and Chukchi Seas, which lie between Alaska and Siberia. The sound source were large, metallic canisters called airguns which filled up with compressed air. The air was released suddenly, like the popping of a balloon. The resulting sound is REALLY loud! The airguns fired 24 hours a day, about every 20 seconds. The airguns hung in the water at a depth of about 15 meters from long cables which were attached to a boom which hung perpendicular to the ship. After the guns were released, bubbles reached the water surface. The sound from the airguns bounces off rock layers beneath the water bottom. A streamer carrying hydrophones was dragged behind the ship for a distance of about 4 km. The ship/streamer configuration looked somewhat like this ship , though this ship is towing multiple streamers, not just one. The streamer was a hollow tube of plastic which carries electronics. The orange object attached to the blue streamer was a "bird", a device which helps keep the streamer at a constant depth by changing the angle of its wings. All of the data coming in from the streamer went through a control room .
Our route was from the Bering Sea, at about the latitude of the Alaskan Peninsula and the longitude of the Bering Strait, northward through the Bering Strait paralleling the Alaskan coast, until reaching the Arctic ice edge . The regional geology was quite varied. We travelled through some rough seas along the way. The route south, on a line farther west (paralleling the US-Russia border) was much more calm.
You can view the 1994 and 1995 AGU Fall Meeting abstracts if you wish.
