A review of seismic detection using fiber optic distributed acoustic sensing: from telecommunication cables to earthquake sensors

Earthquakes are among the most devastating natural disasters, causing widespread ecological destruction and irreparable damage to critical infrastructure. Therefore, proactively monitoring seismic events is essential from a societal and sustainability perspective. Early detection is critical, as changes at the surface often manifest as gradual shifts in seismic wave velocity and attenuation over time. However, the effectiveness of current near-surface earthquake monitoring needs to be improved by spatial and temporal resolution limitations. Dense broadband arrays, while desirable, are often prohibitively expensive for such applications. Fortunately, recent advances have led to the development of distributed acoustic sensing (DAS) systems that ingeniously repurpose fibre optic telecommunication cables into economically feasible high-density seismic arrays. This review provides detailed synthesis and analysis of earthquake detection approaches, particularly the use of DAS with fibre optic systems, including based on backscattered light (Raman, Rayleigh, and Brillouin), interferometric, modulation method, and integration systems, as well as innovations in Fiber network with dark fibre and micro-seismic detection. Moreover, it discusses strategies for improving this technology and overcoming the associated challenges. Integrating artificial intelligence algorithms with multilayer neural networks and convolutional filters in clever Distributed Acoustic Sensing (iDAS) demonstrates great capacity for precise earthquake localization. Optimized geophysical techniques for real-time data transmission highlight advancements in seismic research. A comprehensive evaluation underscores the promise of the DAS era in using global fibre-optic infrastructure for seismic tracking, introducing transformative processes to earthquake propagation research.