Nathaniel B. Palmer 0102 - underway geophysical data

This data set contains underway geophysical data collected on a transit cruise between Cape Town, South Africa, and Punta Arenas, Chile, during April 2001. We collected gravity data using a shipboard Lacoste-Romberg gravimeter, magnetic field data using a proton precession magnetometer towed behind the ship, and centerbeam depth (bathymetry beneath the ship). IGRF2000, calculated for the appropriate date and location, was subtracted from the observed magnetic field to yield the total field magnetic anomaly. The major scientific objectives of the cruise were: a) survey a flowline between the South America and Africa plates just north of the Falkland-Agulhas fracture zone, including across the modern spreading axis, to obtain the magnetic anomaly sequence of the Cretaceous-Cenozoic mixed polarity superchron b) survey a small section of the Agulhas FZ with single-channel seismic data c) survey the northern edge of the Falkland Plateau with swath bathymetry d) collect ADCP data along the track A related data sets that cannot currently be archived at NGDC is single-channel seismic data, which is available from the chief scientist. We expect to archive these files with the University of Texas at Austin in the near future. The SeaBeam data are available in hourly files in raw and edited formats suitable for use with the MB-system software, and cover nearly the entire cruise. These are available from LDEO Antarctic multibeam data management center. The seismic data consist of 24 hours of single-channel seismic reflection profiling across part of the Agulhas fracture zone at 4 deg. W longitude.