DIVE AND SAMPLING LOCATIONS
A single-channel seismic profiler (SCS) was used to reveal subseafloor structures of the Hawaiian volcanoes. The seismic source, or gun, was built by Seismic Systems, Inc., Houston, TX. The 350-cubic-inch gun has both a generator for the primary pulse and an injector for controlling the oscillation of bubbles produced by the generator. For each cruise, the gun was towed at ca. 30 meters aft of the centerline, with towing depth about 5-10 meters. Shooting rate was 20 sec with a ship speed of ca. 5-5.5 knots (ca. 30 meters between shots). Air pressure of the gun was 1300-1740 psi. An analog streamer filled with mineral oil received the acoustic signal reflected off the seafloor. The streamer (made by Services et Instruments de Geophysique, FRANCE) has a 65 meters active section with 48 hydrophones (S.I.G.) and 200 meters of leading cable. Received seismic signals were monitored with an online processing system and recorded in SEG-Y format. Onboard processing of the digital seismic data was performed with Delph Seismic software (TRITON ELICS International, Inc., U.S.A.) and SPW software (GEOSCIENCES, Inc. U.S.A.). Data provided in this release include an ESRI shapefile containing the seismic line locations, a PDF format location map file, an MS Excel file describing the parameters of each seismic line, and PDF images of each seismic line.