Lenz, Kai-Frederik; Gebhardt, Andrea Catalina; Gross, Felix; Lohrberg, Arne; Krastel, Sebastian (2024): 2D multichannel seismic reflection processed data (GI Gun working area dataset) of RV MARIA S. MERIAN during cruise MSM84, Labrador Sea [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.964713

Three 2D reflection seismic profiles from three glacial cross-shelf troughs of the Labrador Shelf, namely the Okak, Makkovik and Cartwright troughs, are presented. The data were collected onboard the Maria S. Merian during cruise and MSM84 using two different multi-channel streamers; a Geometrics GeoEel solid state digital high-resolution streamer (active length 75 m, channel spacing 1.5625 m; hereafter short streamer) and a digital Sercel high-resolution streamer system (active length 600 m, channel spacing 3.125 m; hereafter long streamer). Details regarding the used seismic systems can be found in the cruise report (doi:10.2312/cr_msm84). Data were processed using the commercial VISTA Desktop Seismic Data Processing Software (Schlumberger, version 2018). The standard processing approach included demultiplexing, bulk shifting, frequency filtering (Ormsby as well as in the FK-domain), spiking deconvolution, compensation of spherical divergence and common-midpoint (CMP) binning. The CMP bin size was set to 3.125 m for both datasets. For the short streamer a normal-move-out correction with a constant sound velocity of 1500 ms-1 was performed as the limited offset range of short streamer did not allow for a precise velocity analysis. Afterwards, a static correction was applied as the short streamer was towed close to the water surface. Finally, a CMP stack was calculated followed by a finite differences time migration. The dataset of the long streamer shows a strong receiver ghost, which is related to the tow depth of approximately 10 m below the water surface. This receiver ghost was suppressed. Afterwards, a data-driven velocity analysis was carried out by picking seismic velocities for every 500 CMPs. Normal-move-out correction, CMP stacking and a finite differences time migration were carried out using the velocity field. Finally, a white noise removal was performed. The objective of data recording on the Labrador Shelf is to map glacial landforms and reconstruct the dynamics of the Laurentide Ice Sheet in detail.

Ship time for the cruise MSM84 was funded by the DFG under the award MerMet 17-49, Gebhardt, LABRADOR-GLACIALS.