Nathaniel B. Palmer 0304B underway geophysics

This data set contains underway geophysical data collected on cruise 0304B of the Nathaniel B. Palmer. This cruise went from Barrow, Alaska to Lyttelton, New Zealand via Dutch Harbor, Alaska, Honolulu, Hawaii and Napier, New Zealand. Data sets collected included the following: swath bathymetry (archived at Lamont-Doherty Earth Observatory), gravity and magnetics (archived at the National Geophysical Data Center), ODEC Bathy2000 3.5 kHz echo sounder with subbottom penetration (currently no archive available), and limited multichannel seismic data collected as part of equipment testing. The main scientific objectives of the cruise were as follows: to collect data on the Cenozoic marine magnetic anomalies and seafloor spreading fabric of the Pacific plate south of the Aleutian trench; to acquire detailed bathymetry to fill in some unsurveyed regions around the Hawaiian islands; to study the character of fracture zones south of Hawaii; to survey some lines across the Osbourn Trough, a dead spreading center in the southwest Pacific Ocean, near the Tonga Trench; to survey a line parallel to, and outboard of, the Kermadec trench, in order to study the strength of the Pacific plate in the subduction zone; and to survey an area of gas hydrates east of the North Island of New Zealand. Observations of the seafloor corresponding to the Cretaceous Normal Superchron made along various parts of the track will also contribute to an ongoing study of variations in the intensity of the Earth's magnetic field during the Cretaceous Normal Superchron.