Review of Salas-Romero et al., "Subsurface Structures of a quick-clay sliding prone area..."

Abstract. Quick-clay landslides are common geohazards in Nordic countries and Canada. The presence of potential quick clays is confirmed using geotechnical investigations, but near-surface geophysical methods, such as seismic and resistivity surveys, can also help identifying coarse-grained materials associated to the development of quick clays. We present the results of reflection seismic investigations on land and in part of the Göta River in Sweden, along which many quick-clay landslide scars exist. This is the first time that such a large-scale reflection seismic investigation has been carried out to study the subsurface structures associated with quick-clay landslides. The results also show a reasonable correlation with the radio magnetotelluric and traveltime tomography models. The morphology of the river bottom and riverbanks, as e.g. subaquatic landslide deposits, is shown by side-scan sonar and bathymetric data. Undulating bedrock, covered by subhorizontal sedimentary glacial and postglacial deposits is clearly revealed. An extensive coarse-grained layer exists in the sedimentary sequence and is interpreted and modelled in a regional context. Individual fractures and fracture zones are identified within bedrock and sediments. Hydrological modelling of the coarse-grained layer confirms its potential for transporting fresh water infiltrated in fractures and nearby outcrops. The groundwater flow in the coarse-grained layer promotes leaching of marine salts from the overlying clays by slow infiltration and/or diffusion, which helps in the formation of potential quick clays. Magnetic data show coarse-grained materials at the landslide scar located in the study area, which may have acted as a sliding surface together with quick clays.

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IMPROVED MAP OF SUBSURFACE STRUCTURES IN SOUTHEASTERN NEBRASKA FROM INTEGRATED ANALYSIS OF EARTHQUAKE AND POTENTIAL FIELDS DATASETS

10.1130/abs/2017am-303315 ◽

2017 ◽

Author(s):

Kris Guthrie ◽

◽

Irina Filina ◽

Mindi Searls ◽

Caroline Burberry

Keyword(s):

Potential Fields ◽

Integrated Analysis ◽

Subsurface Structures

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Geomorphology and Landslide-Prone Area in Cisolok District, Sukabumi Regency

E3S Web of Conferences ◽

10.1051/e3sconf/201912501005 ◽

2019 ◽

Vol 125 ◽

pp. 01005 ◽

Cited By ~ 1

Author(s):

Mochamad Seandy Alfarabi ◽

Supriatna ◽

Masita Dwi Mandini Manessa ◽

Andry Rustanto ◽

Yoanna Ristya

Keyword(s):

Land Use ◽

Road Network ◽

Geological Structure ◽

Overlay Analysis ◽

Stream Network ◽

Prone Area ◽

Steep Topography ◽

Physical Variables ◽

Natural Characteristics ◽

Very High

Sukabumi District located in Southern West Java known as a region that has diverse natural characteristics, however, it is vulnerable to disasters, especially landslides. Moreover, this study focuses on Cisolok District because this region always occurred landslides every year due to topography aspect. The aim of this study is to analyze the influence of geomorphology to landslide-prone area in Cisolok District to reduce landslides. This study used overlay analysis for geomorphology mapping, while the Frequency Ratio (FR) method used for landslide-prone area mapping. Several physical variables used in this study such as slope, elevation, lithology, geological structure, road network, stream network, land use, soil type, rainfall, and landslide location. The result shows that the study areas have diverse geomorphology units dominated by volcanic slope with steep topography. While landslide-prone area consist of four classes : namely 17,03% low, 62,05% medium, 14,4% high, and 6,51% very high. Variety of landslide vulnerability in study area influenced by terrain form, land genesis, and geomorphic process.

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Subsurface structures along western Yucatan from integrated geophysical analysis

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2021.104964 ◽

2021 ◽

Vol 127 ◽

pp. 104964

Author(s):

Irina Filina ◽

Lucas Hartford

Keyword(s):

Subsurface Structures

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Snow‐prone area

Weather ◽

10.1002/wea.3940 ◽

2021 ◽

Author(s):

James Dent

Keyword(s):

Prone Area

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Tectonic insight and 3-D modelling of the Lusi (Java, Indonesia) mud edifice through gravity analyses

Geophysical Journal International ◽

10.1093/gji/ggab020 ◽

2021 ◽

Vol 225 (2) ◽

pp. 984-997

Author(s):

Álvaro Osorio Riffo ◽

Guillaume Mauri ◽

Adriano Mazzini ◽

Stephen A Miller

Keyword(s):

Risk Mitigation ◽

Bouguer Anomaly ◽

Geological Model ◽

Resource Exploitation ◽

Subsurface Structures ◽

Central Java ◽

Geostatistical Interpolation ◽

Gravity Response ◽

Anomaly Map ◽

Bouguer Anomaly Map

SUMMARY Lusi is a sediment-hosted hydrothermal system located near Sidoarjo in Central Java, Indonesia, and has erupted continuously since May 2006. This mud eruption extends over a surface of ∼7 km2, and is framed by high containment dams. The present study investigates the geometry of the subsurface structures using a detailed gravimetric model to visualize in 3-D the Lusi system and surrounding lithologies. The obtained residual Bouguer anomaly map, simulated through geostatistical interpolation methods, supports the results of previous deformation studies. The negative gravity anomaly zones identified at Lusi are interpreted as fractured areas through which fluids can ascend towards the surface. A 3-D detailed geological model of the area was constructed with Geomodeller™ to highlight the main features. This model relies on the structures’ density contrasts, the interpreted residual Bouguer anomaly map, and geological data from previous authors. 3-D algorithms were used to calculate the gravity response of the model and validate it by inverse methods. The final output is a gravity constrained 3-D geological model of the Lusi mud edifice. These results provide essential details on the Lusi subsurface and may be useful for possible future geothermal resource exploitation and for the risk mitigation plans related to the maintenance of the man-made framing embankment.

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Velocity Analysis Using Separated Diffractions for Lunar Penetrating Radar Obtained by Yutu-2 Rover

Remote Sensing ◽

10.3390/rs13071387 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1387

Author(s):

Chao Li ◽

Jinhai Zhang

Keyword(s):

Dielectric Permittivity ◽

Lunar Regolith ◽

Velocity Model ◽

Velocity Estimation ◽

Quality Data ◽

High Quality Data ◽

Shallow Subsurface ◽

Subsurface Structures ◽

Ground Penetrating ◽

Permittivity Model

The high-frequency channel of lunar penetrating radar (LPR) onboard Yutu-2 rover successfully collected high quality data on the far side of the Moon, which provide a chance for us to detect the shallow subsurface structures and thickness of lunar regolith. However, traditional methods cannot obtain reliable dielectric permittivity model, especially in the presence of high mix between diffractions and reflections, which is essential for understanding and interpreting the composition of lunar subsurface materials. In this paper, we introduce an effective method to construct a reliable velocity model by separating diffractions from reflections and perform focusing analysis using separated diffractions. We first used the plane-wave destruction method to extract weak-energy diffractions interfered by strong reflections, and the LPR data are separated into two parts: diffractions and reflections. Then, we construct a macro-velocity model of lunar subsurface by focusing analysis on separated diffractions. Both the synthetic ground penetrating radar (GPR) and LPR data shows that the migration results of separated reflections have much clearer subsurface structures, compared with the migration results of un-separated data. Our results produce accurate velocity estimation, which is vital for high-precision migration; additionally, the accurate velocity estimation directly provides solid constraints on the dielectric permittivity at different depth.

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Landslide geometry and activity in Villa de la Independencia (Bolivia) revealed by InSAR and seismic noise measurements

Landslides ◽

10.1007/s10346-021-01659-9 ◽

2021 ◽

Author(s):

Chuang Song ◽

Chen Yu ◽

Zhenhong Li ◽

Veronica Pazzi ◽

Matteo Del Soldato ◽

...

Keyword(s):

Time Series ◽

Seismic Noise ◽

Slip Surface ◽

Inversion Method ◽

Subsurface Structures ◽

Slip Surfaces ◽

Landslide Volume ◽

Noise Measurements ◽

Landslide Body

AbstractInterferometric Synthetic Aperture Radar (InSAR) enables detailed investigation of surface landslide movements, but it cannot provide information about subsurface structures. In this work, InSAR measurements were integrated with seismic noise in situ measurements to analyse both the surface and subsurface characteristics of a complex slow-moving landslide exhibiting multiple failure surfaces. The landslide body involves a town of around 6000 inhabitants, Villa de la Independencia (Bolivia), where extensive damages to buildings have been observed. To investigate the spatial-temporal characteristics of the landslide motion, Sentinel-1 displacement time series from October 2014 to December 2019 were produced. A new geometric inversion method is proposed to determine the best-fit sliding direction and inclination of the landslide. Our results indicate that the landslide is featured by a compound movement where three different blocks slide. This is further evidenced by seismic noise measurements which identified that the different dynamic characteristics of the three sub-blocks were possibly due to the different properties of shallow and deep slip surfaces. Determination of the slip surface depths allows for estimating the overall landslide volume (9.18 · 107 m3). Furthermore, Sentinel-1 time series show that the landslide movements manifest substantial accelerations in early 2018 and 2019, coinciding with increased precipitations in the late rainy season which are identified as the most likely triggers of the observed accelerations. This study showcases the potential of integrating InSAR and seismic noise techniques to understand the landslide mechanism from ground to subsurface.

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