DETERMINATION OF SLIP SURFACES IN FRACTURE ZONE LANDSLIDES USING ORIENTED BOREHOLE CORE SAMPLES

2015 ◽  
Author(s):  
Tsunataka Furuya
Keyword(s):  
Fracture Zone ◽  
Core Samples ◽  
Slip Surfaces ◽  
Borehole Core

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

Landslides ◽  
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.

scholarly journals Determination of Long Horizontal Borehole Height in Roofs and its Application to Gas Drainage

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2647
Author(s):  
Gang Wang ◽  
Cheng Fan ◽  
Hao Xu ◽  
Xuelin Liu ◽  
Rui Wang
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Fracture Zone ◽  
Coalbed Methane ◽  
High Efficiency ◽  
Gas Drainage ◽  
Methane Drainage ◽  
Working Face ◽  
Variation Characteristics

Accurately determining the height of the gas-guiding fracture zone in the overlying strata of the goaf is the key to find the height of the long horizontal borehole in the roof. In order to determine the height, in this study we chose the 6306 working face of Tangkou Coal Mine in China as a research example and used both the theoretical model and discrete element method (DEM) numerical simulation to find the height of the gas-guiding fracture zone and applied the height to drill a long horizontal borehole in the roof of the 6303 working face. Furthermore, the borehole was utilized to deep into the roof for coalbed methane drainage and the results were compared with conventional gas drainage measures from other aspects. The height of the gas-guiding fracture zone was found to be 48.57 m in theoretical model based on the bulk coefficient and the void ratio and to be 51.19 m in the DEM numerical simulation according to the temporal and spatial variation characteristics of porosity. Taking both the results of theoretical analysis and numerical simulation into consideration, we determined that gas-guiding fracture zone is 49.88 m high and applied it to drill a long horizontal borehole deep into the roof in the 6303 working face field. Compared with conventional gas drainage measures, we found that the long horizontal borehole has the high stability, high efficiency and strong adaptability for methane drainage.

Sub-1 mL sample requirement for simultaneous determination of 17 organic and inorganic anions and cations in Antarctic ice core samples by dual capillary ion chromatography

2019 ◽  
Vol 1063 ◽  
pp. 167-177 ◽  
Author(s):  
Estrella Sanz Rodriguez ◽  
Christopher Plummer ◽  
Meredith Nation ◽  
Andrew Moy ◽  
Mark Curran ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Ion Chromatography ◽  
Ice Core ◽  
Inorganic Anions ◽  
Core Samples ◽  
Anions And Cations

scholarly journals The preservation of methanesulphonic acid in frozen ice-core samples

2008 ◽  
Vol 54 (187) ◽  
pp. 680-684 ◽  
Author(s):  
Nerilie J. Abram ◽  
Mark A.J. Curran ◽  
Robert Mulvaney ◽  
Tessa Vance
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
Frozen Storage ◽  
Ice Cores ◽  
Ice Storage ◽  
Core Samples ◽  
Proxy Records ◽  
Subsequent Determination ◽  
Earth’S Climate

AbstractIce-core records of methanesulphonic acid (MSA) provide a potentially powerful tool for producing proxy records of sea ice, a critical but poorly understood component of the Earth’s climate system. However, MSA is able to diffuse through solid ice, and here we examine the effect of two different methods of frozen storage on the preservation of MSA in archived ice-core samples. Re-analysis of archived ice sticks confirms that MSA diffuses out of ice cores archived in this manner. Despite MSA losses of up to 39% after 7 years storage, the ice sticks studied here preserve much of the variability of the original MSA record, suggesting that useful proxy records can be obtained from archived ice sticks. Furthermore, re-analysis of ice-core samples that had been refrozen into discrete bottled samples for storage demonstrates that it is possible to archive ice samples in a way that prevents MSA loss. In this case, accurate records of MSA variability and concentration were preserved even over storage periods of 15 years. This has important implications for the storage of ice cores and subsequent determination of MSA, and demonstrates that ice storage history needs to be considered when interpreting MSA records.

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