Topographic Parametric Sonar (TOPAS) acoustic sub-bottom profiler data acquired on RRS James Clark Ross JR298 cruise in 2015

• Main Authors: Larter, Robert, Hogan, Kelly, Hillenbrand, Claus-Dieter, Gowland, Elanor
• Format: Dataset
• Language: English
• Published: NERC EDS UK Polar Data Centre 2021
• Subjects: "EARTH SCIENCE","SOLID EARTH","TECTONICS","EARTHQUAKES","SEISMIC PROFILE"; "EARTH SCIENCE","OCEANS","MARINE GEOPHYSICS"; Antarctica; Sub-bottom profile; TOPAS; continental rise; sediment; Antarctic; The Antarctic; Antarctic Peninsula; West Antarctica; Drake Passage; Kongsberg; Antarc*
• Online Access: https://dx.doi.org/10.5285/bdfeb69c-df5c-461d-b7a8-583f9daab685; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01517

We present here Topographic Parametric Sonar (TOPAS) acoustic sub-bottom profiler data acquired on RRS James Clark Ross JR298 cruise in 2015. Data are provided in SEG-Y format. This project was funded by UK Natural Environment Research Council Grant NE/J006548/1: Depositional patterns and records in sediment drifts off the Antarctic Peninsula and West Antarctica : These data were collected using a Kongsberg Simrad TOPAS PS018 acoustic sub-bottom profiler. The TOPAS system operated by transmitting a chirp pulse with a frequency band of 1.5-5kHz and length of 10 ms. The receiver had a sample rate of 20 kHz with a trace length of 400 ms, and the gain (in dB) was controlled by the sonar watchkeeper with a range of 2-15 dB and a high-pass filter of 1-2 kHz . Logging of sub-bottom profiler data began at 1514 UTC on Julian day 032, and the system was operated near-continuously during the cruise until 1208 UTC on Julian day 058 when the JCR was approaching Rothera.TOPAS was re-started at 1014 UTC on Julian day 059 and was run until a location in the Drake Passage, 200 nautical miles from the coast at the edge of Argentina's exclusive economic zone. Pinging and logging of TOPAS sub-bottom profiles was stopped for the final time at 1756 UTC on Julian day 060. Additional settings information can be found in the cruise report: https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jr298.pdf : Data were collected using a Kongsberg Simrad TOPAS PS018 sub-bottom profiler : A swept-frequency ("chirp") transmission pulse was used, which required the return signals to be cross-correlated with the source signature (matched filter) throughout the cruise to extract signals with a simple effective waveform, which also has the benefit of reducing random noise (see more information in the cruise report: https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jr298.pdf)