To: “Shallow to very shallow, high‐resolution reflection seismic using a portable vibrator system,” Ranajit Ghose, Vincent Nijhof, Jan Brouwer, Yoshikazu Matsubara, Yasuhiro Kaida, and Toru Takahashi (July‐August 1998 GEOPHYSICS, 63, p. 1295–1309)

Geophysics ◽  
1998 ◽  
Vol 63 (6) ◽  
pp. 2154-2154
Keyword(s):  
High Resolution ◽  
Seismic Reflection ◽  
Time Section ◽  
Reflection Seismic ◽  
Reflection Time

Please refer to page 1302, right column, second full paragraph, first sentence, which currently reads: Figure 10 presents a part of the seismic reflection depth section. It should have read: Figure 10 presents a part of the seismic reflection time section.

Detection of seismic refraction signals using a variance fractal dimension technique

Geophysics ◽  
2000 ◽  
Vol 65 (1) ◽  
pp. 286-292 ◽  
Author(s):  
Lingxiu Jiao ◽  
Wooil M. Moon
Keyword(s):  
Fractal Dimension ◽  
High Resolution ◽  
Seismic Reflection ◽  
Seismic Refraction ◽  
Window Size ◽  
Real Data ◽  
Seismic Signals ◽  
Seismic Reflection Data ◽  
Reflection Seismic ◽  
Reflection Data

Seismic signals in deep crustal surveys are often contaminated with various types of noise, mainly caused by the low signal‐to‐noise (S/N) earth environment. A variance fractal dimension (VFD) technique is investigated and tested with real data sets for detection of seismic refraction signals from background noise. The data tested in this study were collected during the 1992 Lithoprobe Abitibi‐Grenville Transect high‐resolution refraction and wide‐angle reflection seismic experiments. The sharpness of transition features on the VFD trajectory is used as a criterion for distinguishing specific seismic phases. The window size and window interval applied in the application of VFD technique were determined using synthetic seismic data for generation of the optimum VFD trajectory. The window size of 48 samples and the window interval of 8 sample intervals were chosen to calculate the fractal dimension values and create the trajectories for detecting phases Pg, Pn, PmP, and ground roll. The VFD technique was also tested and applied for automatic detection of the first breaks in the high‐resolution seismic reflection data collected during the 1990 Lithoprobe regional and high‐resolution seismic surveys. The sharp transition features corresponding to the first arrivals in the seismic reflection data are distinct and provide us with a robust and powerful tool for separating the seismic signals from noise.

Application of a high‐resolution seismic investigation in a Greek coal mine

Geophysics ◽  
2002 ◽  
Vol 67 (1) ◽  
pp. 50-59 ◽  
Author(s):  
G.‐Akis Tselentis ◽  
Paraskevas Paraskevopoulos
Keyword(s):  
High Resolution ◽  
Coal Mine ◽  
Seismic Reflection ◽  
Seismic Survey ◽  
Coal Field ◽  
Detailed Structure ◽  
Coal Basin ◽  
Geostatistical Methods ◽  
Reflection Seismic ◽  
D Model

High‐resolution seismic methods were applied to map the detailed structure and thickness of the Domeniko coal basin (central Greece) and to search for lateral discontinuities, such as pinch‐outs and faults. Extensive tests were performed to optimize recording parameters and equipment. Reflection events which can be attributed to coal layers can be interpreted from depths of approximately 30 to 150 m on CDP stacked and inverted sections. Several low‐throw faults have been interpreted from the sections. Results obtained from the high‐resolution seismic reflection survey combined with drillhole information clearly revealed the 3‐D model of the coal field. Using geostatistical methods, the results of the high‐resolution reflection seismic survey were combined with the information from the borehole program to clearly reveal the 3‐D model of the basin.

High-Resolution Seismic-Reflection and Marine Magnetic Data Along the Hosgri Fault Zone, Central California

2009 ◽  
Author(s):  
Ray W. Sliter ◽  
Peter J. Triezenberg ◽  
Patrick E. Hart ◽  
Janet T. Watt ◽  
Samuel Y. Johnson ◽  
...  
Keyword(s):  
High Resolution ◽  
Fault Zone ◽  
Seismic Reflection ◽  
Magnetic Data ◽  
Central California

The use of geophysical prospecting for imaging active faults in the Roer Graben, Belgium

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Donat Demanet ◽  
François Renardy ◽  
Kris Vanneste ◽  
Denis Jongmans ◽  
Thierry Camelbeeck ◽  
...  
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Fault Zone ◽  
Geophysical Methods ◽  
Depth Range ◽  
Electrical Tomography ◽  
Reflection Seismic ◽  
Refraction Seismic ◽  
Geophysical Surveys ◽  
Geophysical Techniques

As part of a paleoseismological investigation along the Bree fault scarp (western border of the Roer Graben), various geophysical methods [electrical profiling, electromagnetic (EM) profiling, refraction seismic tests, electrical tomography, ground‐penetrating radar (GPR), and high‐resolution reflection seismic profiles] were used to locate and image an active fault zone in a depth range between a few decimeters to a few tens of meters. These geophysical investigations, in parallel with geomorphological and geological analyses, helped in the decision to locate trench excavations exposing the fault surfaces. The results could then be checked with the observations in four trenches excavated across the scarp. Geophysical methods pointed out anomalies at all sites of the fault position. The contrast of physical properties (electrical resistivity and permittivity, seismic velocity) observed between the two fault blocks is a result of a differences in the lithology of the juxtaposed soil layers and of a change in the water table depth across the fault. Extremely fast techniques like electrical and EM profiling or seismic refraction profiles localized the fault position within an accuracy of a few meters. In a second step, more detailed methods (electrical tomography and GPR) more precisely imaged the fault zone and revealed some structures that were observed in the trenches. Finally, one high‐resolution reflection seismic profile imaged the displacement of the fault at depths as large as 120 m and filled the gap between classical seismic reflection profiles and the shallow geophysical techniques. Like all geophysical surveys, the quality of the data is strongly dependent on the geologic environment and on the contrast of the physical properties between the juxtaposed formations. The combined use of various geophysical techniques is thus recommended for fault mapping, particularly for a preliminary investigation when the geological context is poorly defined.

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