Near-surface Voids in the Neapolitan Volcanic Tuff (Italy) Detected by Seismic Refraction Tomography

2015 ◽  
Author(s):  
S. Maraio ◽  
P.P.G. Bruno
Keyword(s):  
Seismic Refraction ◽  
Near Surface ◽  
Volcanic Tuff ◽  
Refraction Tomography

scholarly journals Geophysical investigations for stability and safety mitigation of regional crude-oil pipeline near abandoned coal mines

2021 ◽  
Vol 18 (1) ◽  
pp. 145-162
Author(s):  
B Butchibabu ◽  
Prosanta Kumar Khan ◽  
P C Jha
Keyword(s):  
High Resolution ◽  
Crude Oil ◽  
Seismic Refraction ◽  
High Resolution Imaging ◽  
Weak Zone ◽  
Near Surface ◽  
Oil Pipeline ◽  
Refraction Tomography ◽  
Geophysical Investigations ◽  
Resolution Imaging

Abstract This study aims for the protection of a crude-oil pipeline, buried at a shallow depth, against a probable environmental hazard and pilferage. Both surface and borehole geophysical techniques such as electrical resistivity tomography (ERT), ground penetrating radar (GPR), surface seismic refraction tomography (SRT), cross-hole seismic tomography (CST) and cross-hole seismic profiling (CSP) were used to map the vulnerable zones. Data were acquired using ERT, GPR and SRT along the pipeline for a length of 750 m, and across the pipeline for a length of 4096 m (over 16 profiles of ERT and SRT with a separation of 50 m) for high-resolution imaging of the near-surface features. Borehole techniques, based on six CSP and three CST, were carried out at potentially vulnerable locations up to a depth of 30 m to complement the surface mapping with high-resolution imaging of deeper features. The ERT results revealed the presence of voids or cavities below the pipeline. A major weak zone was identified at the central part of the study area extending significantly deep into the subsurface. CSP and CST results also confirmed the presence of weak zones below the pipeline. The integrated geophysical investigations helped to detect the old workings and a deformation zone in the overburden. These features near the pipeline produced instability leading to deformation in the overburden, and led to subsidence in close vicinity of the concerned area. The area for imminent subsidence, proposed based on the results of the present comprehensive geophysical investigations, was found critical for the pipeline.

Stratigraphic Analysis with Refraction Tomography

2019 ◽  
Vol 25 (3) ◽  
pp. 245-254
Author(s):  
Peter J. Hutchinson ◽  
Maggie H. Tsai
Keyword(s):  
Seismic Refraction ◽  
High Energy ◽  
P Wave ◽  
Tidal Channels ◽  
Near Surface ◽  
Precambrian Rocks ◽  
Stratigraphic Analysis ◽  
P Wave Velocity ◽  
Refraction Tomography ◽  
Near Shore

ABSTRACT Near-surface seismic refraction tomography imaged the basal contact of the Upper Cambrian silica-rich Mount Simon Formation with that of the underlying Precambrian granite in central Wisconsin. The discrimination between the Mount Simon and underlying non-conformable contact with Precambrian rocks was based upon a p-wave velocity of 1,700 m/s. Refraction tomography imaged deep, broad tidal channels within the Mount Simon consistent with the inference that Mount Simon was deposited in a high-energy near-shore, probably fluvial environment. The Mount Simon is an arenite that has high commercial value.

Foundation Evaluation of a Repeater Installation Building using Electrical Resistivity Tomography and Seismic Refraction Tomography

2019 ◽  
Vol 24 (1) ◽  
pp. 27-38
Author(s):  
B. Butchibabu ◽  
Prosanta K. Khan ◽  
P.C. Jha
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Seismic Refraction ◽  
P Wave ◽  
S Wave ◽  
Resistivity Tomography ◽  
Near Surface ◽  
Refraction Tomography ◽  
Subsurface Layers ◽  
Geophysical Investigations

Geophysical investigations were carried out for evaluation of damage and to assess the possible causes for repeated occurrence of damage at one of the buildings constructed for oil pumping in the northern part of India. Electrical Resistivity Tomography (ERT) and Seismic Refraction Tomography (SRT) techniques were adopted for studying the subsurface of the area around the building with an objective of ascertaining the cause of damage. High resolution imaging was done using both the techniques in this investigation. ERT delineated the presence of low resistivity (2 ohm-m) water filled voids below the structures and mapped different subsurface layers such as sandy soil, clay and sandstone in the study area. SRT revealed P-wave velocity ( V P ) of the subsurface medium in the range of 400–3,400 m/s. Corresponding densities and S-wave velocities ( V S ) were determined based on Gardner's and Castagna's relationships. Subsequently, the V P , V S and the modulus values were used in estimating compressibility of soil and rock strata. Results showed near surface layers were characterized by high compressibility (26.673 × 10 −5 Pa −1 ), decreases with depth. This paper presents the details of the site, techniques used in the investigation and correlation of geophysical results with lithological information, and the subsequent analysis for understanding the distress in the subsurface of the study area.

scholarly journals Neotectonic Activity in the Low-Strain Broken Foreland (Santa Bárbara System) of the North-Western Argentinean Andes (26°S)

Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 1-25
Author(s):  
Ahmad Arnous ◽  
Martin Zeckra ◽  
Agostina Venerdini ◽  
Patricia Alvarado ◽  
Ramón Arrowsmith ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Seismic Reflection ◽  
Seismic Refraction ◽  
Sedimentary Basins ◽  
Santa Barbara ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
South Central ◽  
Refraction Tomography ◽  
Fault Scarps

Abstract Uplift in the broken Andean foreland of the Argentine Santa Bárbara System (SBS) is associated with the contractional reactivation of basement anisotropies, similar to those reported from the thick-skinned Cretaceous-Eocene Laramide province of North America. Fault scarps, deformed Quaternary deposits and landforms, disrupted drainage patterns, and medium-sized earthquakes within the SBS suggest that movement along these structures may be a recurring phenomenon, with yet to be defined repeat intervals and rupture lengths. In contrast to the Subandes thrust belt farther north, where eastward-migrating deformation has generated a well-defined thrust front, the SBS records spatiotemporally disparate deformation along structures that are only known to the first order. We present herein the results of geomorphic desktop analyses, structural field observations, and 2D electrical resistivity tomography and seismic-refraction tomography surveys and an interpretation of seismic reflection profiles across suspected fault scarps in the sedimentary basins adjacent to the Candelaria Range (CR) basement uplift, in the south-central part of the SBS. Our analysis in the CR piedmont areas reveals consistency between the results of near-surface electrical resistivity and seismic-refraction tomography surveys, the locations of prominent fault scarps, and structural geometries at greater depth imaged by seismic reflection data. We suggest that this deformation is driven by deep-seated blind thrusting beneath the CR and associated regional warping, while shortening involving Mesozoic and Cenozoic sedimentary strata in the adjacent basins was accommodated by layer-parallel folding and flexural-slip faults that cut through Quaternary landforms and deposits at the surface.

scholarly journals Pyroclastic Deposits Identification using Near-Surface Seismic Refraction Tomography in Rawa Dano Volcanic Complex, Banten, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012062
Author(s):  
Maryadi Maryadi ◽  
Nanda Aminy Ilahi Bisgar ◽  
Luthfi Yufajjiru ◽  
Rifqi Rizqulloh ◽  
Ghozy El Fatih ◽  
...  
Keyword(s):  
Seismic Velocity ◽  
Longitudinal Velocity ◽  
Seismic Refraction ◽  
Volcanic Eruptions ◽  
Volcanic Complex ◽  
Pyroclastic Deposits ◽  
Near Surface ◽  
Lack Of Information ◽  
Refraction Tomography ◽  
Seismic Refraction Survey

Abstract Rawa Dano is a caldera lake which resulted from Dano Purba Volcano’s massive eruption, and it produced a huge amount of pyroclastic deposits that typically formed complex volcaniclastic series. Due to the lack of information regarding the subsurface properties of Rawa Dano area, therefore in this study, a low-energy seismic refraction survey was carried out to identify the distribution of pyroclastic deposits resulted from intensive volcanic eruptions. The data were acquired from two lines in two different sites. Variations of longitudinal velocity in the seismic vertical cross-section suggest that there are more than one type of deposits existed in the area. The results show two main refractors which are related to the deposition of different facies. The seismic velocity shown in the upper part of the seismic tomography model indicates that the pyroclastic deposit has a great thickness. This finding suggests that the eruptions happened massively. By combining the results from both sites, it could be inferred that the preceding one is even bigger in magnitude. The result is in agreement with the earlier surface geological study, which explains a similar conclusion. This research demonstrates the capability of seismic refraction tomography to map the distribution and condition of volcanic deposits around Rawa Dano Volcanic Complex.

scholarly journals Landslide Investigation Using Seismic Refraction Tomography Method: A Review

2021 ◽  
Vol 64 (Vol. 64 (2021)) ◽  
Author(s):  
Parisa Imani ◽  
Amr Abd El-Raouf ◽  
Gang Tian
Keyword(s):  
Water Saturation ◽  
Mass Movement ◽  
Seismic Refraction ◽  
Cost Effective ◽  
Time Lapse ◽  
Near Surface ◽  
Advantages And Disadvantages ◽  
Refraction Tomography ◽  
Landslide Mass ◽  
Novel Algorithms

Since the early 1960s, near-surface seismic refraction tomography (SRT) has been extensively used as a non-invasive and cost-effective geophysical method to characterize complex geological structures for landslide investigation. This geophysical technique is able to characterize the slope material, the sliding surface's geometry, the landslide mass movement, the physical properties of media, and the water saturation effects on the slope. Therefore, this method has become an appropriate method due to the increasing progress of novel algorithms and the improvements of field-data collection systems. In this paper, we attempt to review the essential research that investigated various types of landslides influenced by water saturation and landslide materials and identified in various areas, since the year 2000. Significant conclusions obtained by applying different survey strategies and data processing algorithms in seismic refraction surveys are widely discussed concentrating on the advantages and disadvantages of this method. The main results obtained by the few available studies applying time-lapse SRT (TLSRT) are particularly analyzed.

scholarly journals Near-surface seismic refraction tomography and MASW for site characterization in Phuentsholing, Bhutan Himalaya

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Raju Sarkar ◽  
Sreevalsa Kolathayar ◽  
Dowchu Drukpa ◽  
Kinley Choki ◽  
Shrijana Rai ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Seismic Refraction ◽  
P Wave ◽  
Response Analysis ◽  
Soil Parameters ◽  
Near Surface ◽  
Engineering Construction ◽  
Refraction Tomography

AbstractIt is essential to understand the soil characteristics of the subsurface layers for any engineering construction. In difficult terrains like hilly areas, conventional methods of investigation are expensive and difficult to conduct. It calls for nondestructive testing methods to get reliable estimates of subsurface properties. In the present study, seismic refraction tomography (SRT) technique and multichannel analysis of surface waves (MASW) methods were carried out along five selected profiles in Phuentsholing region of Bhutan Himalaya. The profile length ranges from 37 to 81.5 m, and depth of imaging down to 10 m. While the SRT data imaged the P-wave velocity (Vp) structures, the MASW imaged the shear wave velocity (Vs) structures. The P-wave images provide a fair knowledge of geological layers, while the MASW images provide S-wave velocity structures (Vs). These results are useful to estimate soil parameters, like the density, Poisson’s ratio, Young’s modulus, shear modulus, N-value and the ultimate bearing capacity. The seismic images reveal the presence of sand, sandy clay, gravels and shale layers below the selected sites. Bhutan Himalayas being seismically vulnerable, the obtained results in terms of shear wave velocity were accustomed to categorize the sites as per NEHRP site classes, and a ground response analysis was performed to determine the reliable amplification factors. From the study, it is suggested that the engineering construction is feasible at all the sites except in one site, where an indication of saturated soil is observed which is vulnerable for liquefaction, and ground needs to be improved before construction at that site.

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