This dataset is part of a Distributed Fiber Optic Strain Sensing (DFOS) study along a dark fiber for monitoring purposes conducted on an optical fiber link between Boxmeer and Deurne in the Netherlands. The work investigates the application of DFOS using existing dark fiber infrastructure from telecommunication companies to capture strain variations along tens of kilometers with high spatial and temporal resolution. The experiment covered the time period from 2025-06-25 08:19:32 UTC to 2025-08-11 11:56:03 UTC. This data set contains the recordings covering the arrival of seismic waves from the 2025 M8.8 Kamchatka earthquake between 2025-07-29 23:30:01 UTC to 2025-07-30 01:15:46 UTC. Recordings with the QuantX-system contain the following settings: gauge length of 20 m, channel spacing of 2 m, and a sampling rate of 250 Hz. The dark fiber has a length of nearly 36 km, leading to a total of 18,100 channels in each file. File naming follows the start timestamp in BTS. The 26 geo-referenced channel locations from tap tests and/or locatable noise sources are contained in this data set as well.
