A Continuous DAS Dataset of the 2 April 2024 Mw 7.4 Hualien, Taiwan, Earthquake Sequence from the MiDAS Observatory

Abstract Distributed acoustic sensing (DAS) enables optical fibers to function as dense seismic arrays, providing continuous ground-motion observations with high spatial resolution. We present a DAS dataset of the 2 April 2024 Mw 7.4 Hualien, Taiwan, earthquake sequence recorded by the Milun fault Drilling and All-inclusive Sensing project, a permanent fault-zone observatory in eastern Taiwan. The dataset spans 7 days before the mainshock and 30 days afterward, capturing a total of 5944 seismic events with ML≥0.0 and providing detailed constraints on sequence evolution. Although recordings of the mainshock and several large aftershocks exhibit signal saturation due to instrumental limitations, the dataset remains suitable for analyses of small-to-moderate events. Waveforms are distributed in MiniSEED format with DAS channels represented as virtual stations and are openly available together with fiber geometry and metadata. This dataset provides a valuable resource for investigating earthquake processes across a wide range of magnitudes, leveraging the high spatial and temporal resolution of DAS recordings, and demonstrates the potential of DAS for large-scale seismic data sharing.