Berndt, Christian; Canals, Miquel; Urgeles, Roger; Camerlenghi, Angelo; Papenberg, Cord (2022): 2D reflection seismic data from Eivissa Channel, western Mediterranean Sea during RRS Charles Darwin cruise CD178 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.943523

3D reflection seismic data were acquired using the P-Cable system of the National Oceanographic Centre, Southampton, UK during cruise 178 Leg 2 onboard RRS Charles Darwin between the 5th and 8th of April 2006. The responsible PI's was C. Berndt, Southampton Oceanography Centre, Southampton, UK. The aim of this cruise was to map submarine landslides on the eastern slopes of the Eivissa Channel, western Mediterranean Sea located between the islands of Ibiza-Formentera and the Spanish mainland. Berndt et al. (2012) used the acquired data to study repeated slope failure linked to fluid migration, while Lafuerza et al. (2012) studied geotechnical aspects of slope stability using this as additional data. Acquisition parameters: The source during seismic acquisition consisted of four 40 in3 Bolt 600B air guns spaced 0.75 m apart and tower at a depth of 1.5 m about 20 m behind the stern of the vessel (Berndt et al., 2012). The air guns are fitted with wave shape kits that emit approximately 10 in3 of air prior to the main volume to reduce the bubble pulse. The air pressure is 2000 psi, and the gun controller triggers the guns to figure every 7 seconds. The data were collected with 11 single-channel analogue streamers that were towed 10 m apart. The seismic cube in the Eivissa Channel covers an area of ca. 14 km2 (ca. 6.4 EW x 2.2 NS km) located at 306091.83 4280497.41; 305951.42 4278353.92; 312321.94 4277936.57 in UTM zone 31N. 2D seismic processing: During seismic processing of the 3D dataset significant ghost-artefacts were identified because some of the streamers were towed too deep. This required de-ghosting. Unfortunately, these attempts did not yield improved quality of the 3D seismic data. This was mainly because the 12.5 m streamers were too short for commonly used de-ghosting technique used in the industry. To increase vertical resolution individual 2D profiles were extracted from the raw dataset. Processing steps included frequency bandpass filtering, burst noise attenuation, binning, NMO-correction, stacked, and a Stolt migration with 1520 ms-1 was applied that resulted in higher resolution 2D profiles for 85 lines and 11 streamers (channels).