WEGA (WilkEs basin GlAcial history) project

WEGA is an international, multidisciplinary project, funded by the Italian PNRA and the Australian Antarctic Division (AAD). The data were collected during the January-March 2000 cruise aboard the R/V Tangaroa (NZ). The data are: 1827 km of high resolution, multi-channel, seismic reflection data, 3.5 kHz profiles, 562 km of chirp data, and a total of 11 gravity cores, 28 piston cores, 18 surface grabs and 11 short trigger cores. The water depth of the investigated area is between 100 and 3500 meters, from the inner continental shelf to the continental rise.

The aim of the project is to reconstruct the Cenozoic evolution of the East Antarctic Ice Sheet, and of the bottom current production throughout the investigation of the sedimentary sequences deposited in the Wilkes Land continental margin between 68 degree South and 64 degree South of latitude and between 142 degree E and 146 degree E of longitude.

Recording parameters of the WEGA reflection seismic multi-channel data: Source: 2X150 GI Airgun (6.8 liters) Streamer length: 600 m Hydroscience Technologies Recording: Geometrix 48-channels RX seismograph with 24-bit resolution Operating pressure: 2000 psi Number of Channels: 48 Sampling rate: 1 millisecond Group interval: 12.5 m Max record length: 7 seconds Shot interval: variable from 5 seconds (12.5 m at 5 knot survey speed) to 10 seconds (25 m at 5 knot survey speed) Number of phones per group: 16 Coverage: variable from 1000% to 2400% Field Filters: Low cut: 10 HZ -24 db/Oct High cut: 250 HZ – 70 db/Oct Processing parameters of the WEGA reflection seismic multi-channel data: Anti-alias filter and resample to 2 ms, Amplitude recovery, Apply gain recovery to compensate for spherical divergence and transmission loss. Sort data into CDP order and WB profile application. Normal move-out correction using velocity function. Derived from common distance gathers and mute scans. Stack 2400% Filter Time variant bandpass filter application. Sum of two adjacent traces.