Seismic Interferometry and Wave Propagation Analysis

Seismic interferometry exploits the continuous background of ambient seismic noise or controlled sources to recover the impulse response between pairs of receivers, effectively turning one sensor into a virtual source for its neighbour. By cross-correlating long time series of seismic records, empirical Green’s functions emerge that characterise wave propagation paths through the subsurface. These methods enable high‐resolution imaging of geological structures, temporal monitoring of stress and fluid variations, and detection of subtle velocity changes without the need for active sources. Complementary approaches such as ambient noise tomography and surface‐wave dispersion analysis extend these capabilities by constructing three‐dimensional velocity models and by resolving depth-dependent shear-wave velocity profiles. Together, seismic interferometry and wave propagation analysis offer non-invasive tools for earthquake hazard assessment, groundwater management, reservoir monitoring and urban site characterisation. Their global significance lies in the ability to track both long-term tectonic processes and short-term environmental or anthropogenic perturbations with unprecedented spatial and temporal fidelity.

Research from Nature Portfolio

Recent studies have demonstrated the versatility of fibre-optic cables as distributed seismic sensors, capturing high-resolution moisture dynamics in the vadose zone of semi-arid regions. By treating pre-installed telecommunication lines as dense arrays of passive receivers, researchers have tracked sub-seasonal precipitation events and drought-induced evapotranspiration losses, corroborating zero-dimensional hydrological models and highlighting the need for integrated in-situ validation. In urban environments, broadband seismometers positioned within city centres have been shown to detect and discriminate road traffic, subway operations and cultural events through their unique wavefield signatures. These observations underline the potential of continuous noise recording to monitor infrastructure health and urban microzonation, thereby bridging fundamental wave propagation research with practical engineering and outreach applications.

Research from all publishers

Continuous seismic monitoring across a major fault zone has revealed pronounced diurnal to monthly velocity variations induced by Earth tides, with heightened sensitivity in densely fractured regions. These observations underscore the role of periodic stress modulation on crack aperture and fluid pressure, offering a novel window into fault zone mechanics during seismic quiescence. A new short-term synchronous–asynchronous ambient noise tomography scheme applied in karst terrains combines limited backbone stations with dense nodal deployments to reconstruct three-dimensional shear-wave velocity models. The approach successfully delineated low-velocity cavities corresponding to caves, demonstrating a cost-effective protocol for urban geohazard assessment. Seminal work on cross-correlations of ambient seismic noise first revealed coherent broadband Rayleigh waves at global scales, laying the foundation for modern interferometric imaging and enabling dispersion measurements along paths inaccessible to traditional ballistic surface waves.

Seismic Interferometry and Wave Propagation Analysis publication trend

The graph below shows the total number of articles in seismic interferometry and wave propagation analysis across all publications each year (not limited to Nature Index journals).

Technical terms

Seismic interferometry: A technique that retrieves the impulse response between two receivers by cross-correlating ambient or passive seismic recordings.

Ambient noise: Continuous background vibrations from natural and anthropogenic sources used as virtual seismic sources.

Cross-correlation function: A mathematical operation that measures the similarity between two time series as a function of time lag, revealing travel-time information.

Empirical Green’s function: The estimated wavefield between two sensors obtained through interferometric processing, equivalent to the response from an impulsive source.

Rayleigh waves: Surface seismic waves that propagate along the Earth’s surface and exhibit dispersive behaviour dependent on subsurface layering.

Dispersion analysis: The study of frequency-dependent wave velocity to infer subsurface elastic and structural properties.

References

1. Fiber-optic seismic sensing of vadose zone soil moisture dynamics. Nature Communications (2024).
2. Urban Seismology: on the origin of earth vibrations within a city. Scientific Reports (2017).
3. Pronounced temporal velocity variations within the fault fracture zone in response to Earth tide modes. National Science Review (2025).
4. Short-Term Synchronous and Asynchronous Ambient Noise Tomography in Urban Areas: Application to Karst Investigation. Engineering (2025).
5. Emergence of broadband Rayleigh waves from correlations of the ambient seismic noise. Geophysical Research Letters (2004).