Interferometric body-wave retrieval from ambient noise after polarization filtering: Application to shallow reflectivity imaging

Abstract

Interferometric retrieval of body waves from ambient noise recorded at surface stations is usually challenged by the dominance of surface-wave energy, in particular in settings dominated by anthropogenic activities (e.g., natural resource exploitation, traffic, infrastructure construction). As a consequence, ambient noise imaging of shallow structures such as sedimentary layers remains a difficult task for sparse and irregularly distributed receiver networks. We demonstrate how polarization filtering can be used to automatically extract steeply inclined P-waves from continuous three-component recordings and in turn improves passive body-wave imaging. Being a single-station approach, the technique does not rely on a dense receiver array and is therefore well suited for data collected during surveillance monitoring for tasks such as reservoir hydraulic stimulation, CO_2 sequestration, and wastewater disposal injection. We apply the method on a continuous dataset acquired in the Wellington oilfield (Kansas, US), where local and regional seismicity, and other forms of ambient noise provide an abundant source of both surface- and body-wave energy recorded at 15 short-period receivers. We use autocorrelation to derive the shallow (lt; 1 km) reflectivity structure below the receiver array and validate our workflow and results with well logs and active seismic data. Raytracing analysis and waveform modeling indicates that converted shear waves need to be taken into account for realistic ambient noise body-wave source distributions, as they can be projected on the vertical component and might lead to misinterpretation of the P-wave reflectivity structure. Overall, our study suggests that polarization filtering significantly improves passive body-wave imaging on both autocorrelation and interstation crosscorrelation. It reduces the impact of time-varying noise source distributions and is therefore also potentially useful for time-lapse ambient noise interferometry.

Evaluation of Various Data Acquisition Scenarios for the Retrieval of Seismic Body Waves from Ambient Noise Seismic Interferometry Technique via Numerical Modeling

“…Unfortunately, the vertical resolution of the seismic profile retrieved from the surface wave seismic interferometry is relatively insufficient to extract information from deep layers for exploration purposes. On the other hand, some studies have also been conducted, though it has proven to be more challenging than it is for surface waves, to extract body wave reflections from the deep subsurface structures from the cross-correlation of ambient noise [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The successful extraction of the body wave reflections from the seismic background noise demonstrates promise in applications of geophysical exploration and time-lapse monitoring of petroleum and geothermal reservoirs deep in the earth.…”

Imaging a paleovalley with passive seismic methods: Evidence for glacial carving of Unaweep Canyon (Colorado, US)

“…However, due to lack of well-defined and steeply incident body waves, only a few studies have used ambient noise AC for shallow targets (e.g., Saygin et al, 2017;Heath et al 2018). Other studies have applied preprocessing of ambient noise to select body-waves from local seismicity (Dangwal & Behm, 2021) and local micro-earthquakes (Polychronopoulou et al, 2020) to improve shallow reflectivity retrieval from AC. An alternate approach uses teleseismic signals with near-vertical incidence to image deep crustal (Abe et al, 2007;Ruigrok & Wapenaar, 2012;Wang et al, 2020) and shallow structures (Pham & Tkalcic, 2017Viens et al, 2022).…”