The South Island Seismology at the Speed of Light Experiment (SISSLE): Distributed Acoustic Sensing Across and Along the Alpine Fault, South Westland, New Zealand

Distributed acoustic sensing (DAS) is positioned to revolutionize observational seismology by providing dense spatial sampling and temporal resolution. DAS repurposes long sections (1–10s of kilometers) of fiber-optic cable into thousands of individual sensors at meter spacing and uses light to measure the ground motion as seismic waves pass through the fiber. The South Island Seismology at the Speed of Light experiment involved the acquisition of DAS data from two dark telecommunication fibers along the highway near Haast, South Westland, New Zealand that run perpendicularly across the Alpine Fault and subparallel to the Alpine Fault and Tasman Sea coastline. The DAS acquisition was supplemented by the deployment of 24 nodal seismometers within 1 km of the surface trace of the Alpine Fault. We introduce the experimental setup, share initial processing steps, and preliminary observations from the DAS array deployed in two phases for nearly five months between late-February and mid-May 2023 and again in October–November 2023.