Seismic offset balancing

Geophysics ◽  
1994 ◽  
Vol 59 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Christopher P. Ross ◽  
Paul L. Beale
Keyword(s):  
Seismic Data ◽  
Amplitude Variation With Offset ◽  
Reflection Seismic ◽  
Optimal Processing ◽  
Theoretical Predictions ◽  
Back Ground ◽  
Seismic Records ◽  
The Many ◽  
Seismic Reflections ◽  
The Relationship

The ability to successfully predict lithology and fluid content from reflection seismic records using AVO techniques is contingent upon accurate pre‐analysis conditioning of the seismic data. However, all too often, residual amplitude effects remain after the many offset‐dependent processing steps are completed. Residual amplitude effects often represent a significant error when compared to the amplitude variation with offset (AVO) response that we are attempting to quantify. We propose a model‐based, offset‐dependent amplitude balancing method that attempts to correct for these residuals and other errors due to sub‐optimal processing. Seismic offset balancing attempts to quantify the relationship between the offset response of back‐ground seismic reflections and corresponding theoretical predictions for average lithologic interfaces thought to cause these background reflections. It is assumed that any deviation from the theoretical response is a result of residual processing phenomenon and/or suboptimal processing, and a simple offsetdependent scaling function is designed to correct for these differences. This function can then be applied to seismic data over both prospective and nonprospective zones within an area where the theoretical values are appropriate and the seismic characteristics are consistent. A conservative application of the above procedure results in an AVO response over both gas sands and wet sands that is much closer to theoretically expected values. A case history from the Gulf of Mexico Flexure Trend is presented as an example to demonstrate the offset balancing technique.

Ground-roll attenuation using curvelet downscaling

Geophysics ◽  
2018 ◽  
Vol 83 (3) ◽  
pp. V185-V195 ◽  
Author(s):  
Mostafa Naghizadeh ◽  
Mauricio Sacchi
Keyword(s):  
Seismic Data ◽  
Curvelet Transform ◽  
Low Frequencies ◽  
High Frequencies ◽  
Seismic Records ◽  
Mask Function ◽  
Ground Roll ◽  
Least Squares Optimization ◽  
Seismic Reflections ◽  
Content Information

We have developed a ground-roll attenuation strategy for seismic records that adopts the curvelet transform. The curvelet transform decomposes the seismic events based on their dip and frequency content information. The curvelet panels that contain only either reflection or ground-roll energy can be used to alter the curvelet panels with mixed reflection and ground-roll energies. We build a curvelet-domain mask function from the ground-roll-free curvelet coefficients (high frequencies) and downscale it to the ground-roll-contaminated curvelet coefficients (low frequencies). The mask function is used inside a least-squares optimization scheme to preserve the seismic reflections and attenuate the ground roll. Synthetic and real seismic data examples show the application of the proposed ground-roll attenuation method.

VIBROSEIS DOWN THE HOLE

1983 ◽  
Vol 23 (1) ◽  
pp. 203
Author(s):  
J. T. Frazer
Keyword(s):  
Seismic Data ◽  
Seismic Source ◽  
Seismic Signal ◽  
Structure Mapping ◽  
Time Duration ◽  
Seismic Section ◽  
Reflection Seismic ◽  
The Past ◽  
Field Estimation ◽  
Seismic Reflections

A variety of problems associated with the Vibroseis® source have been encountered over the past few years which have presented difficulties in tieing surveys using different control systems and in depth mapping.Accurate depth structure mapping and field estimation from seismic data requires good correlation of seismic reflections with stratigraphic boundaries. The information required, a known seismic signal and vertical rock velocities can only be obtained from measurements down the hole.Seismic time to depth correlation can be obtained from an integrated sonic velocity curve tied to conventional well shoot data only if the source is the same as that used for the reflection seismic data or the relation between the well shoot and seismic source is known. It has been apparent for some time that the signal from the Vibroseis source has not been adequately defined from surface measurements.A number of parameters must be monitored to ensure that the signal transmitted during a Vibroseis sweep is properly calibrated. The synchronisation of phase, time duration of the sweep, sweep bandwidth, vibrator drive levels and the phase relation of the pilot sweep to the signal transmitted from the baseplate, contribute to determine the character of the signal seen on a seismic section.®Trademark of Conoco, Inc.

The impact of cultural factors on attachment dynamics: a view from Irish society

2019 ◽  
Vol 13 (2) ◽  
pp. 207-223
Author(s):  
Michael O’Toole
Keyword(s):  
Significant Role ◽  
Emotional Development ◽  
Cultural Factors ◽  
Seamus Heaney ◽  
Irish Society ◽  
Irish Context ◽  
Key Points ◽  
The Many ◽  
The Impact ◽  
The Relationship

In this article I examine aspects of the relationship between mothers and sons from an attachment perspective in an Irish context. Through the works of Irish writers such as Seamus Heaney, John McGahern, and Colm Tóibín, I focus on particular aspects of this relationship, which fails to support the developmental processes of separation and individuation in the many men who come to me for psychotherapy. I illustrate key points concerning this attachment dynamic through the use of clinical examples of my work with two men from my practice. While acknowledging that many other cultural factors play a significant role in the emotional development of children, integrating the work of our poets, novelists, and scholars with an attachment perspective

John Cranko's Antigone (1959): A Ballet Lost and Found

2015 ◽  
Vol 33 (1) ◽  
pp. 1-15
Author(s):  
Henrietta Bannerman
Keyword(s):  
World War Ii ◽  
Jean Racine ◽  
World War ◽  
Martha Graham ◽  
Detailed Consideration ◽  
Lost And Found ◽  
The Many ◽  
Tragic Drama ◽  
The Relationship

John Cranko's dramatic and theatrically powerful Antigone (1959) disappeared from the ballet repertory in 1966 and this essay calls for a reappraisal and restaging of the work for 21st century audiences. Created in a post-World War II environment, and in the wake of appearances in London by the Martha Graham Company and Jerome Robbins’ Ballets USA, I point to American influences in Cranko's choreography. However, the discussion of the Greek-themed Antigone involves detailed consideration of the relationship between the ballet and the ancient dramas which inspired it, especially as the programme notes accompanying performances emphasised its Sophoclean source but failed to recognise that Cranko mainly based his ballet on an early play by Jean Racine. As Antigone derives from tragic drama, the essay investigates catharsis, one of the many principles that Aristotle delineated in the Poetics. This well-known effect is produced by Greek tragedies but the critics of the era complained about its lack in Cranko's ballet – views which I challenge. There is also an investigation of the role of Antigone, both in the play and in the ballet, and since Cranko created the role for Svetlana Beriosova, I reflect on memories of Beriosova's interpretation supported by more recent viewings of Edmée Wood's 1959 film.

Archaeologists and the Dead

2016 ◽  
Keyword(s):  
Historical Context ◽  
Ethical Considerations ◽  
International Context ◽  
The Public ◽  
The Us ◽  
The Dead ◽  
The Many ◽  
The Uk ◽  
The Relationship ◽  
Experience Effect

This volume addresses the relationship between archaeologists and the dead, through the many dimensions of their relationships: in the field (through practical and legal issues), in the lab (through their analysis and interpretation), and in their written, visual and exhibitionary practice--disseminated to a variety of academic and public audiences. Written from a variety of perspectives, its authors address the experience, effect, ethical considerations, and cultural politics of working with mortuary archaeology. Whilst some papers reflect institutional or organizational approaches, others are more personal in their view: creating exciting and frank insights into contemporary issues that have hitherto often remained "unspoken" among the discipline. Reframing funerary archaeologists as "death-workers" of a kind, the contributors reflect on their own experience to provide both guidance and inspiration to future practitioners, arguing strongly that we have a central role to play in engaging the public with themes of mortality and commemoration, through the lens of the past. Spurred by the recent debates in the UK, papers from Scandinavia, Austria, Italy, the US, and the mid-Atlantic, frame these issues within a much wider international context that highlights the importance of cultural and historical context in which this work takes place.

scholarly journals Micromechanism of the Breakage of Two Spherical Gypsum Particles under Normal–Tangential Contact Conditions

2021 ◽  
Vol 11 (9) ◽  
pp. 4039
Author(s):  
Yiran Niu ◽  
Lin Li ◽  
Yanwei Zhang ◽  
Shicai Yu ◽  
Jian Zhou
Keyword(s):  
Tangential Force ◽  
Coarse Grained ◽  
Spherical Particles ◽  
Contact Conditions ◽  
Normal Contact ◽  
Tangential Contact ◽  
Theoretical Predictions ◽  
Tangential Forces ◽  
Predicted Values ◽  
The Relationship

Contact breakage of particles makes a large difference in the strength of coarse-grained soils, and exploring the characteristics within the process of the breakage is of great significance. Ignoring the influence of particle shape, the micromechanism of two spherical particles breaking under normal–tangential contact conditions was investigated theoretically and experimentally. Through theoretical analysis, the breakage form, the shape and size of the conical core, and the relationship between the normal and tangential forces at crushing were predicted. Particle contact tests of two gypsum spheres were carried out, in which the breakage forms, features of the conical cores and the normal and tangential forces at crushing were recorded for comparison with the predicted values. The test results and the theoretical predictions showed good agreement. Both the analysis and test demonstrate that the presence of tangential forces causes the conical core to assume the shape of an oblique cone, and the breakage form to change. Moreover, with increasing normal contact force, the tangential force needed for crushing increases gradually first and then decreases suddenly.

scholarly journals Grounding semantic transparency in context

Morphology ◽  
2021 ◽  
Author(s):  
Rossella Varvara ◽  
Gabriella Lapesa ◽  
Sebastian Padó
Keyword(s):  
Large Scale ◽  
Point Of View ◽  
Distributional Semantics ◽  
Semantic Transparency ◽  
Inclusion Measure ◽  
The Difference ◽  
Semantic Point ◽  
The Many ◽  
The Relationship

AbstractWe present the results of a large-scale corpus-based comparison of two German event nominalization patterns: deverbal nouns in -ung (e.g., die Evaluierung, ‘the evaluation’) and nominal infinitives (e.g., das Evaluieren, ‘the evaluating’). Among the many available event nominalization patterns for German, we selected these two because they are both highly productive and challenging from the semantic point of view. Both patterns are known to keep a tight relation with the event denoted by the base verb, but with different nuances. Our study targets a better understanding of the differences in their semantic import.The key notion of our comparison is that of semantic transparency, and we propose a usage-based characterization of the relationship between derived nominals and their bases. Using methods from distributional semantics, we bring to bear two concrete measures of transparency which highlight different nuances: the first one, cosine, detects nominalizations which are semantically similar to their bases; the second one, distributional inclusion, detects nominalizations which are used in a subset of the contexts of the base verb. We find that only the inclusion measure helps in characterizing the difference between the two types of nominalizations, in relation with the traditionally considered variable of relative frequency (Hay, 2001). Finally, the distributional analysis allows us to frame our comparison in the broader coordinates of the inflection vs. derivation cline.

Coherent noise in marine seismic data

Geophysics ◽  
1983 ◽  
Vol 48 (7) ◽  
pp. 854-886 ◽  
Author(s):  
Ken Larner ◽  
Ron Chambers ◽  
Mai Yang ◽  
Walt Lynn ◽  
Willon Wai
Keyword(s):  
Seismic Data ◽  
Noise Suppression ◽  
Seismic Source ◽  
Coherent Noise ◽  
Critical Data ◽  
Predictive Deconvolution ◽  
Scattered Energy ◽  
Marine Seismic ◽  
The Many ◽  
Water Bottom

Despite significant advances in marine streamer design, seismic data are often plagued by coherent noise having approximately linear moveout across stacked sections. With an understanding of the characteristics that distinguish such noise from signal, we can decide which noise‐suppression techniques to use and at what stages to apply them in acquisition and processing. Three general mechanisms that might produce such noise patterns on stacked sections are examined: direct and trapped waves that propagate outward from the seismic source, cable motion caused by the tugging action of the boat and tail buoy, and scattered energy from irregularities in the water bottom and sub‐bottom. Depending upon the mechanism, entirely different noise patterns can be observed on shot profiles and common‐midpoint (CMP) gathers; these patterns can be diagnostic of the dominant mechanism in a given set of data. Field data from Canada and Alaska suggest that the dominant noise is from waves scattered within the shallow sub‐buttom. This type of noise, while not obvious on the shot records, is actually enhanced by CMP stacking. Moreover, this noise is not confined to marine data; it can be as strong as surface wave noise on stacked land seismic data as well. Of the many processing tools available, moveout filtering is best for suppressing the noise while preserving signal. Since the scattered noise does not exhibit a linear moveout pattern on CMP‐sorted gathers, moveout filtering must be applied either to traces within shot records and common‐receiver gathers or to stacked traces. Our data example demonstrates that although it is more costly, moveout filtering of the unstacked data is particularly effective because it conditions the data for the critical data‐dependent processing steps of predictive deconvolution and velocity analysis.

A discussion of apraxia, aphasia, and gestural language

1984 ◽  
Vol 246 (6) ◽  
pp. R884-R887
Author(s):  
N. Helm-Estabrooks
Keyword(s):  
Sign Language ◽  
Cerebral Hemisphere ◽  
Communication Disorder ◽  
Left Cerebral Hemisphere ◽  
Language Behavior ◽  
Normal Language ◽  
Symbolic Gestures ◽  
The Many ◽  
The Relationship ◽  
The Brain

It is understood that damage to the left cerebral hemisphere in adulthood may result in syndromes of language disturbances called the aphasias. The study of these syndromes sheds light on normal language processes, the relationship between language behavior and the brain, and how best to treat aphasic individuals. Aphasia, for some, is a central communication disorder affecting all symbolic behavior in all modalities (i.e., speech, writing, and gesture). Difficulty producing symbolic gestures on command is called apraxia. Others view aphasia as a manifestation of a motor-sequencing disorder affecting all gestural systems including those required for speech movements. These divergent theories of the underlying nature of aphasia can be tested through examination of deaf individuals who use sign language before onset of aphasia. Poizner et al. [Am. J. Physiol. 246 (Regulatory Integrative Comp. Physiol. 15): R868-R883, 1984] studied three such patients with different aphasia syndromes: one patient had a nonsymbolic, motor-sequencing disorder; one had a gestural apraxia; and one had neither. These findings force the conclusion that neither the symbolic nor motor-sequencing theory of aphasia can account for the many varieties of that disorder.

A method of ground‐roll elimination

Geophysics ◽  
1988 ◽  
Vol 53 (7) ◽  
pp. 894-902 ◽  
Author(s):  
Ruhi Saatçilar ◽  
Nezihi Canitez
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Wave Motion ◽  
Frequency Interval ◽  
Vertical Resolution ◽  
Matched Filters ◽  
One Dimensional ◽  
Frequency Bands ◽  
Ground Roll ◽  
Seismic Reflections

Amplitude‐ and frequency‐modulated wave motion constitute the ground‐roll noise in seismic reflection prospecting. Hence, it is possible to eliminate ground roll by applying one‐dimensional, linear frequency‐modulated matched filters. These filters effectively attenuate the ground‐roll energy without damaging the signal wavelet inside or outside the ground roll’s frequency interval. When the frequency bands of seismic reflections and ground roll overlap, the new filters eliminate the ground roll more effectively than conventional frequency and multichannel filters without affecting the vertical resolution of the seismic data.

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