THE ATTENUATION CONSTANT OF EARTH MATERIALS

Geophysics ◽  
1941 ◽  
Vol 6 (2) ◽  
pp. 132-148 ◽  
Author(s):  
W. T. Born
Keyword(s):  
Seismic Reflection ◽  
Seismic Waves ◽  
Attenuation Factor ◽  
Laboratory Data ◽  
Sound Waves ◽  
Reflection Method ◽  
Viscous Losses ◽  
Seismic Reflection Method ◽  
Solid Friction ◽  
Data Frequency

This paper discusses briefly the nature of viscous losses and solid friction losses, both of which may cause sound waves to be attenuated as they travel through a physical medium. A simple experimental technique for determining the nature and magnitude of the loss factor in small rock samples is described, and data are given which indicate that solid friction losses are primarily responsible for the observed attenuation of the seismic waves employed in the seismic reflection method. A method of estimating the attenuation factor of earth materials from seismic reflection records is outlined and it is shown that the values so obtained are not inconsistent with the laboratory data. Frequency characteristic curves of seismic wave paths are derived on the basis of the experimental data.

Detecting Abandoned Air-Raid Shelter Using The S-Wave Seismic Reflection Method

2008 ◽  
Author(s):  
Shunichiro Ito ◽  
Takao Aizawa ◽  
Fumio Nakada ◽  
Ryosuke Kitamura
Keyword(s):  
Seismic Reflection ◽  
Reflection Method ◽  
S Wave ◽  
Seismic Reflection Method

Seismic Reflection Expression of Reactivated Structures in the New Madrid Rift Complex

1988 ◽  
Vol 59 (4) ◽  
pp. 141-150 ◽  
Author(s):  
John. L. Sexton
Keyword(s):  
Seismic Reflection ◽  
Structural Features ◽  
Normal Faults ◽  
Earthquake Activity ◽  
Seismic Zone ◽  
Reflection Method ◽  
Intraplate Earthquakes ◽  
Reflection Data ◽  
Seismic Reflection Method ◽  
New Madrid

Abstract An important aspect of seismogenesis concerns the role of preexisting faults and other structural features as preferred zones of weakness in determining the pattern of strain accumulation and seismicity. Reactivation of zones of weakness by present day stress fields may be the cause of many intraplate earthquakes. To understand the relation between reactivated structures and seismicity, it is necessary to identify structures which are properly oriented with respect to the present-day stress field so that reactivation can occur. The seismic reflection method is very useful for identifying and delineating structures, particularly in areas where the structures are buried as in the New Madrid seismic zone. Application of the seismic reflection method in widely separated locations within the New Madrid rift complex has resulted in successful detection and delineation of reactivated rift-related structures which are believed to be associated with earthquake activity. The purpose of this paper is to discuss results from seismic reflection profiling in the New Madrid rift complex. Reflection data from several surveys including USGS Vibroseis* surveys in the Reelfoot rift area reveal reactivated faults and other deep rift-related structures which appear to be associated with seismicity. High-resolution explosive and Mini-Sosie** reflection surveys on Reelfoot scarp and through the town of Cottonwood Grove, Tennessee, clearly show reverse faults in Paleozoic and younger rocks which have been reactivated to offset younger rocks. A Vibroseis survey in the Wabash Valley area of the New Madrid rift complex provides direct evidence for a few hundred feet of post-Pennsylvanian age reactivation of large-offset normal faults in Precambrian-age basement rocks. Several earthquake epicenters have been located in the vicinity of these structures. In the Rough Creek graben, Vibroseis reflection data provide clear evidence for reactivation of basement faults. The success of these reflection surveys shows that well-planned seismic reflection surveys must be included in any program seeking to determine the relationship between preexisting zones of weakness and seismicity of an area.

scholarly journals Seismic Evidence of a Wet Zone Under the West Antarctic Ice Sheet

1976 ◽  
Vol 16 (74) ◽  
pp. 73-88 ◽  
Author(s):  
Gilbert Dewart
Keyword(s):  
Thermal Regime ◽  
Acoustic Impedance ◽  
Seismic Reflection ◽  
Ice Sheet ◽  
Reflection Method ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Seismic Reflection Method

AbstractIt appears to be possible to identify certain conditions of thermal regime at the base of a glacier through the seismic reflection method. In some cases layers of water or wet rock debris may be identifiable. The procedure is based upon the reversal of phase of reflected dilatational waves at the interface between ice and a substratum of lower acoustic impedance. Illustrations of the method are given from the west Antarctic ice sheet, and suggestions are made for the improvement of the technique.

scholarly journals Shallow seismic reflection survey for imaging deep-seated coal layer - Case study from Muara Enim coal

2021 ◽  
Vol 24 (1) ◽  
pp. 15-29
Author(s):  
Muhammad Ramdhani ◽  
◽  
Muhammad Ibrahim ◽  
Hans Siregar ◽  
Tony Rahadinata ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Coalbed Methane ◽  
Coal Gasification ◽  
Reflection Method ◽  
Borehole Data ◽  
Seismic Section ◽  
Shallow Seismic ◽  
Coal Layer ◽  
Seismic Reflection Method ◽  
Amplitude Characteristics

Indonesia has a great potential for deep-seated coal resources. To assist and support the deep-seated coal exploration, a shallow seismic reflection method is applicable for this purpose. This study has conducted a shallow seismic reflection method in Musi Banyuasin Regency, South Sumatera Province. The Muara Enim coal target varies from 100 to 500 meters from the surface. The thickness of the coal layer varies from 2 to 10.65 meters. This study uses 48 channels with 14 Hz single geophone and MiniSosie as the energy source. The receiver and source interval is 15 meters. This study uses a fixed receiver and moving source configuration. From the interpreted seismic section, this study identified a deep-seated coal layer target. These layers are Mangus, Burung, Benuang, Kebon and Benakat layers. A simple interpretation is analyzed by combining the seismic amplitude characteristics and the thickness of the coal layer from the borehole data. From the interpreted seismic section, deep-seated coal layer targets have strong amplitude characteristics and are continuous from southwest to the northeast with a down-dip of around 20-30°. This study helps to inform the operator companies who develop the utilization of deep-seated coal (coalbed methane, underground coal gasification and underground coal mining) about the effective and proper geophysical method for imaging deep-seated coal layer.

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