The raw 2D multichannel seismic reflection data in this project were acquired during expedition SO294 offshore Vancouver Island, Canada, using two different sources, i.e. a single GI gun and a G-gun array. The data were recorded with an 184-channel streamer. The objectives of expedition SO294 were twofold: provision of geophysical images to constrain the hazard potential of the Cascadia subduction zone and to constrain the geophysical properties of the oceanic crust to assess its storage potential for carbon capture and storage (CCS). The data comprise 1660 line kilometers and are provided in raw format (SEG-D) according to standard metadata descriptions. Detailed information on the acquisition can be found in the SO294 cruise report (https://doi.org/10.48433/cr_so294). In addition, a technical report is provided with this data set.

We acknowledge the Nuu-Chah-Nulth Tribal Council (NTC) and their member Nations as well as the Quatsino and Pacheedaht Nations on whose marine traditional territories we conducted our science.The Federal Ministry of Education and Research (BMBF) funded the project under grants 03G0294A (CLOCKS) and 03G0294B (CASCADIA) with extra funding and the use of large-scale equipment from GEOMAR.Further additional funding has been provided through the Japan Society for the promotion of Science (JSPS), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), University of Tokyo, Kobe University, Geological Survey of Canada (Public Safety Geoscience Program), Ocean Networks Canada, and the University of Alberta for the land MT-Program.