Data Report: Underway and Site-Survey Geophysics, Leg 133

Abstract

Site-survey geophysical data collected prior to Leg 133 and underway geophysical data collected during Leg 133 were indispensable parts of the Ocean Drilling Program (ODP) drilling process off northeastern Australia. During 1987, BMR's vessel Rig Seismic collected 1400 km of multichannel, water-gun seismic reflection data and associated bathymetric, gravity, and magnetic data throughout the region to be drilled, and this formed the site-survey data set that was used to refine the scientific objectives and to select the final drill sites. During Leg 133, the JOIDES Resolution seismic crew collected 3222 nmi (5971 km) of underway geophysical data on transits to and between sites and over the sites themselves. These data were mainly bathymetric and magnetic data, but also included 154 nmi (285 km) of single-channel water-gun seismic reflection data over the sites to confirm their positions prior to drilling. Together, these data sets play an important part in our understanding of the regional significance of the drilling results.