This data set was acquired with the LDEO Multi-Channel Seismic system during the 2018 R/V Marcus G. Langseth expedition MGL1803 (Co-Chief Scientists: Michael Gurnis, Sean Gulick, Joann Stock, Harm vanAvendonk). The data files are in SEG-D format and contain Multi-Channel Seismic Reflection shot data that has not been processed. The data set was acquired as part of the project called Collaborative Research: SISIE: South Island, New Zealand, Subduction Initiation Experiment. Funding was provided by NSF awards OCE16-54689 and OCE16-54766.