Ambient noise surface wave tomography to determine the shallow shear velocity structure at Valhall: depth inversion with a Neighbourhood Algorithm

Mordret, Aurélien; Landès, Matthieu; Shapiro, N. M.; Singh, S. C.; Roux, Philippe

doi:10.1093/gji/ggu217

Cited by 92 publications

(84 citation statements)

References 59 publications

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“…From the CCs between each station pair, we obtain the group velocity dispersion curves using a narrow band‐pass multiple‐filtering analysis following the method of Levshin et al (). We use a graphical user interface that involves analyst validation of the dispersion curves and the possibility to manually pick them (Mordret et al, ). To identify and reject unreliable group velocity measurements, we use only the CCs that have a signal‐to‐noise ratio equal to or larger than 10 and an interstation distance of more than 1.5 wavelengths.…”

Section: Ambient Noise Tomographymentioning

confidence: 99%

“…Due to the lack of significant local seismicity in the region (Obermann et al, ), local earthquake tomography methods (Kissling, ; Koulakov & Shapiro, ; Thurber, ) could not be applied to investigate the subsurface velocity variations in the area below Lusi and the neighboring volcanic complex. A viable tool that has provided excellent results, also in volcanic environments, is ambient noise tomography (ANT) (Brenguier et al, ; Jaxybulatov et al, ; Luzón et al, ; Masterlark et al, ; Mordret et al, ; Obermann et al, ; Stankiewicz et al, ; Villagómez et al, ). The ANT method inverts dispersive surface waves across station pairs using long‐lasting records of seismic noise (Campillo & Paul, ; Claerbout, ; Lobkis & Weaver, ; Shapiro & Campillo, ).…”

Section: Introductionmentioning

confidence: 99%

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The Plumbing System Feeding the Lusi Eruption Revealed by Ambient Noise Tomography

et al. 2017

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Lusi is a sediment‐hosted hydrothermal system featuring clastic‐dominated geyser‐like eruption behavior in East Java, Indonesia. We use 10 months of ambient seismic noise cross correlations from 30 temporary seismic stations to obtain a 3‐D model of shear wave velocity anomalies beneath Lusi, the neighboring Arjuno‐Welirang volcanic complex, and the Watukosek fault system connecting the two. Our work reveals a hydrothermal plume, rooted at a minimum 6 km depth that reaches the surface at the Lusi site. Furthermore, the inversion shows that this vertical anomaly is connected to the adjacent volcanic complex through a narrow (~3 km wide) low velocity corridor slicing the survey area at a depth of ~4–6 km. The NE‐SW direction of this elongated zone matches the strike of the Watukosek fault system. Distinct magmatic chambers are also inferred below the active volcanoes. The large‐scale tomography features an exceptional example of a subsurface connection between a volcanic complex and a solitary erupting hydrothermal system hosted in a hydrocarbon‐rich back‐arc sedimentary basin. These results are consistent with a scenario where deep‐seated fluids (e.g., magmas and released hydrothermal fluids) flow along a region of enhanced transmissivity (i.e., the Watukosek fault system damage zone) from the volcanic arc toward the back arc basin where Lusi resides. The triggered metamorphic reactions occurring at depth in the organic‐rich sediments generated significant overpressure and fluid upwelling that is today released at the spectacular Lusi eruption site.

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Section: Ambient Noise Tomographymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Plumbing System Feeding the Lusi Eruption Revealed by Ambient Noise Tomography

et al. 2017

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“…Therefore, the Monte Carlo method has some disadvantages such as the large computational cost, due to the huge number of models to be used, and the strong dependence on the choice of the confidence criterion which highly affects the uncertainties in the best model. Nevertheless, the method is fairly robust, so that the convergence towards the global minimum is guaranteed: as a fact, the value assumed by the EF in each iteration decreases progressively during the inversion (Shapiro and Ritzwoller 2002;Mordret et al 2014). The Monte Carlo multimodal algorithm was subdivided into four steps.…”

Section: Inversion Of the Dispersion Curvesmentioning

confidence: 99%

Crustal and uppermost mantle S-wave velocity below the East European Craton in northern Poland from the inversion of ambient-noise records

Lepore

Polkowski

Grad

2018

Int J Earth Sci (Geol Rundsch)

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The P-wave velocities (V p ) within the East European Craton in Poland are well known through several seismic experiments which permitted to build a high-resolution 3D model down to 60 km depth. However, these seismic data do not provide sufficient information about the S-wave velocities (V s ). For this reason, this paper presents the values of lithospheric V s and P-wave-to-S-wave velocity ratios (V p /V s ) calculated from the ambient noise recorded during 2014 at "13 BB star" seismic array (13 stations, 78 midpoints) located in northern Poland. The 3D V p model in the area of the array consists of six sedimentary layers having total thickness within 3-7 km and V p in the range 1.85.3 km/s, a three-layer crystalline crust of total thickness ~ 40 km and V p within 6.15-7.15 km/s, and the uppermost mantle, where V p is about 8.25 km/s. The V s and V p /V s values are calculated by the inversion of the surface-wave dispersion curves extracted from the noise cross correlation between all the station pairs. Due to the strong velocity differences among the layers, several modes are recognized in the 0.021 Hz frequency band: therefore, multimodal Monte Carlo inversions are applied. The calculated V s and V p /V s values in the sedimentary cover range within 0.992.66 km/s and 1.751.97 as expected. In the upper crust, the V s value (3.48 ± 0.10 km/s) is very low compared to the starting value of 3.75 ± 0.10 km/s. Consequently, the V p /V s value is very large (1.81 ± 0.03). To explain that the calculated values are compared with the ones for other old cratonic areas.

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“…• The Monte Carlo Neighborhood Algorithm (MCNA) inversion described by Sambridge (1999), Mordret et al (2014) and Lepore et al (2018) was applied to the starting Rayleigh-wave phase velocity dispersion curve. As a starting model, we chose a layered 1D profile considering the thickness, the S-wave velocity, the density and the Poisson's ratio as parameters.…”

Section: S-wave Velocity Models From Surface Wavesmentioning

confidence: 99%

The geophysical characteristic of the lower lithosphere and asthenosphere in the marginal zone of the East European Craton

Grad

Puziewicz

Majorowicz³

et al. 2018

Int J Earth Sci (Geol Rundsch)

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Seismic P-and S-wave velocities of the lower lithosphere and underlying asthenosphere at the SW margin of the East European Craton in northern Poland were obtained with different seismic techniques: seismic refraction, P-residuals of the first arrivals from teleseismic earthquakes, P-wave receiver function, and inversion of the Rayleigh surface wave dispersion curves, the last two using data collected in the passive seismic experiment "13 BB star". The uniform array consisted of 13 stations deployed in a 120 km in diameter area. Below the depth of 180-220 km a decrease of about 6% of the S-wave velocity is interpreted as a thermal gradient zone corresponding to a lithosphere-asthenosphere transition. The average mantle velocities down to a depth of 300 km beneath the array are relatively high, exceeding values for other Precambrian cratons by 0.1-0.2 km/s, and cannot be modeled by reasonable mantle peridotite compositions in the lithospheric part of the profile. We suggest that significant peridotite anisotropy could explain the misfit between measured and calculated seismic velocities in the lithosphere.

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Ambient noise surface wave tomography to determine the shallow shear velocity structure at Valhall: depth inversion with a Neighbourhood Algorithm

Cited by 92 publications

References 59 publications

The Plumbing System Feeding the Lusi Eruption Revealed by Ambient Noise Tomography

The Plumbing System Feeding the Lusi Eruption Revealed by Ambient Noise Tomography

Crustal and uppermost mantle S-wave velocity below the East European Craton in northern Poland from the inversion of ambient-noise records

The geophysical characteristic of the lower lithosphere and asthenosphere in the marginal zone of the East European Craton

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