Advances in marine geophysical research of continental margins

1968 ◽  
Vol 5 (4) ◽  
pp. 963-983 ◽  
Author(s):  
J. Lamar Worzel
Keyword(s):  
Transition Zone ◽  
Gravity Data ◽  
Sedimentary Cover ◽  
Seismic Refraction ◽  
Continental Margins ◽  
Geophysical Research ◽  
Continental Shelves ◽  
America South ◽  
Seismic Refraction Data ◽  
Refraction Data

Geophysical data available for the continental margins of North America, South America, Africa, and Europe are examined and summarized. Seismic reflection profiling provide much detail of the uppermost sedimentary cover; seismic refraction data delineate the broad outlines of the upper crustal layers; and gravity data restrict the choices of the deeper crustal structure and that of the upper mantle.Conclusions about the variability of the sedimentation at the various continental shelves, slopes, and rises are given. The transition zone between continental and oceanic structure is restricted to a narrow zone varying between 50 km and 300 km in width for various coasts. This transition zone is localized in the region of the 2000 m isobath for all the coasts studied. The continental margins are generally in isostatic equilibrium as a whole, although departing from this equilibrium somewhat, expecially in the transition zone.

scholarly journals Utilization of seismic refraction data for the study of structure of Bang hot-water source, Le Thuy, Quang Binh

2016 ◽  
Vol 38 (4) ◽  
Author(s):  
Tran Anh Vu* ◽  
Dinh Van Toan ◽  
Doan Van Tuyen ◽  
Lai Hop Phong ◽  
Duong Thi Ninh ◽  
...  
Keyword(s):  
Seismic Refraction ◽  
Water Source ◽  
Hot Water ◽  
Seismic Refraction Data ◽  
Refraction Data

scholarly journals Detailed shallow structure seismic refraction investigation, with the application of different processing techniques

2001 ◽  
Vol 34 (4) ◽  
pp. 1309
Author(s):  
Τ. ΠΑΠΑΔΟΠΟΥΛΟΣ ◽  
Π. ΚΑΜΠΟΥΡΗΣ ◽  
Ι. ΑΛΕΞΟΠΟΥΛΟΣ
Keyword(s):  
Seismic Velocity ◽  
Seismic Refraction ◽  
Seismic Sources ◽  
Subsurface Structure ◽  
Seismic Refraction Data ◽  
Processing Techniques ◽  
National Road ◽  
Gradual Variation ◽  
Refraction Data ◽  
Shallow Structure

A comparative study of conventional and modern processing techniques of seismic refraction data is examined in this paper, for shallow structure investigation in the framework of a geotechnical research. The techniques used here were applied for the detection of narrow and low seismic velocity zones along the bedrock in the 10.5th Km of the new national road Igoumenitsa-Ioannina. The results were comparable and only slight deviations were observed due mainly to different algorithm procedures applied on data and the resolution provided by each technique. It is pointed out that the non linear tomography seismic refraction technique, overcomes the conventional ones since by increasing the number of seismic sources and considering the gradual variation of seismic velocity with depth, a better resolution and image reconstruction for the subsurface structure is obtained.

Refrapy: A Python program for seismic refraction data analysis

2022 ◽  
Vol 159 ◽  
pp. 105020
Author(s):  
Victor José Cavalcanti Bezerra Guedes ◽  
Susanne Taina Ramalho Maciel ◽  
Marcelo Peres Rocha
Keyword(s):  
Data Analysis ◽  
Seismic Refraction ◽  
Seismic Refraction Data ◽  
Refraction Data

A New Inversion Method Using a Modified Bat Algorithm for Analysis of Seismic Refraction Data in Dam Site Investigation

2019 ◽  
Vol 24 (2) ◽  
pp. 201-214
Author(s):  
Rashed Poormirzaee ◽  
Siamak Sarmady ◽  
Yusuf Sharghi
Keyword(s):  
Seismic Data ◽  
Seismic Refraction ◽  
Bat Algorithm ◽  
Inversion Method ◽  
Model Parameters ◽  
Inversion Algorithm ◽  
Dam Site ◽  
Seismic Refraction Data ◽  
Modified Bat Algorithm ◽  
Refraction Data

Similar to any other geophysical method, seismic refraction method faces non-uniqueness in the estimation of model parameters. Recently, different nonlinear seismic processing techniques have been introduced, particularly for seismic inversion. One of the recently developed metaheuristic algorithms is bat optimization algorithm (BA). Standard BA is usually quick at the exploitation of the solution, while its exploration ability is relatively poor. In order to improve exploration ability of BA, in the current study, a hybrid metaheuristic algorithm by inclusion a mutation operator into BA, so-called mutation based bat algorithm (MBA), is introduced to inversion of seismic refraction data. The efficiency and stability of the proposed inversion algorithm were tested on different synthetic cases. Finally, the MBA inversion algorithm was applied to a real dataset acquired from Leylanchay dam site at East-Azerbaijan province, Iran, to determine alluvium depth. Then, the performance of MBA on both synthetic and real datasets was compared with standard BA. Moreover, the dataset was further processed following a tomographic approach and the results were compared to the results of the proposed MBA inversion method. In general, the MBA inversion results were superior to standard BA inversion and results of MBA were in good agreement with available boreholes data and geological sections at the dam site. The analysis of the seismic data showed that the studied site comprises three distinct layers: a saturated alluvial, an unsaturated alluvial, and a dolomite bedrock. The measured seismic velocity across the dam site has a range of 400 to 3,500 m/s, with alluvium thickness ranging from 5 to 19 m. Findings showed that the proposed metaheuristic inversion framework is a simple, fast, and powerful tool for seismic data processing.

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