Seismic Surveys, Australia (2015)

This data set is a summary of seismic survey transects from 1961 to 2015. The data was summarised to 0.1 deg grids and the number of km of the grid surveyed over a 5 year period was calculated. Geoscience Australia is releasing its 2014 version of the Marine Seismic Surveys Shape and Kml files. These files have been updated to include recent openfile surveys. The spatial files have been created from a cleansed, updated collection of p190 navigation files. This navigation collection has grown from the checking of navigation submitted to the GA Repository under the Offshore Petroleum and Greenhouse Gas Storage Regulationshttp://www.ga.gov.au/metadata-gateway/metadata/record/gcat_f5f24293-c9c1-6ed9-e044-00144fdd4fa6/Marine+Seismic+Survey+Shape+and+Kml+Files+-+2014+VersionThis data contains geographical information in shapefiles that represent 2D and 3D seismic surveys from 1961 to 2013.They represent most of the seismic surveys shot around Australia. According to Mike Sexton (pers. comm., 2013; GA) 3D surveys are modern surveys that shoot with multiple cables, acquiring many times more data than a 2D survey. The cables have no impact on the environment. Over time, seismic surveys have used a variety of sources commencing with dynamite in the 1960s (usually 50 lbs, but sometimes 200 lbs). The shot spacing was usually of the order of 200 m. Since then, electrical discharges (sparkers), gas-exploders, vibratory sources and air guns have been used. The shot interval has been reduced to about 20 m.