Array length magnification through the use of multiple sources and receiving arrays

For wide aperture seismic experiments, very long effective arrays can be synthesized by using multiple sources and receiving arrays. In marine seismic work where a source is coincident with the end of each array, the total length of the arrays can be multiplied by a factor between [Formula: see text] and n, where n is the number of sources. Three ships, each with a source and 3.6-km array, can be positioned so that the offset range 0 to 25.2 km can be continuously sampled with duplication only in the 0 to 3.6-km range. With 100-m group spacing these data can be gathered into 252-fold common‐depth‐point (CDP) data with a CDP spacing of 150 m. While it is not likely that we will ever see five or six ships steaming in line, two and three ships will be used in the near future for detailed sedimentary and deep crustal studies.

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Use of autoconvolution to suppress first‐order, long‐period multiples

Geophysics ◽

10.1190/1.1442010 ◽

1985 ◽

Vol 50 (9) ◽

pp. 1410-1425 ◽

Cited By ~ 7

Author(s):

C. J. Tsai

Keyword(s):

Single Channel ◽

Primary Energy ◽

Low Frequencies ◽

First Order ◽

Seismic Wavelet ◽

Common Depth Point ◽

Band Limited ◽

Marine Seismic ◽

Prediction Problems ◽

Water Bottom

A common problem in interpreting marine seismic data is the interference of water‐bottom multiples with primary reflections containing the structural or stratigraphic information. In deep ‐water areas, where considerable primary energy arrives before the first simple water‐bottom multiple, weak and deep crustal reflections are often obscured by the first‐order water‐bottom multiples. In order to obtain a more interpretable section, a technique involving a two‐step process was developed to suppress the first‐order water‐bottom multiples. First, the relation between the zero‐order, water‐bottom primary and its first‐order, simple water‐bottom multiple is used to derive statistically an inverse of the seismic wavelet in order to remove its effect, i.e., to wavelet‐shape the data. This wavelet processing provides a band‐limited estimate of the subsurface impulse response. The second step consists of using the autoconvolution of the wavelet‐shaped primary energy to estimate deterministically and subtract the actual first‐order, water‐bottom multiples, The method was applied to field data from the deep Gulf of Mexico. Different incidence angles for the input primaries and multiples, as well as dipping reflecting interfaces, introduce uncompensated traveltime errors. These errors reduce the ability to suppress multiples, thus restricting the validity of the method to low frequencies where common‐depth‐point stacking is less effective. On the other hand, curved interfaces may also cause amplitude prediction problems. In spite of this, the first‐order, water‐bottom multiple energy is significantly reduced (by up to 18 dB) on dip‐filtered, single‐channel data.

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Two-dimensional full wavefield inversion of wide-aperture marine seismic streamer data

Geophysical Journal International ◽

10.1046/j.1365-246x.2002.01645.x ◽

2002 ◽

Vol 151 (2) ◽

pp. 325-344 ◽

Cited By ~ 235

Author(s):

Richard M. Shipp ◽

Satish C. Singh

Keyword(s):

Two Dimensional ◽

Wide Aperture ◽

Marine Seismic ◽

Streamer Data ◽

Wavefield Inversion

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Marine seismic triple source case studies from the Asia–Pacific region

The APPEA Journal ◽

10.1071/aj17131 ◽

2018 ◽

Vol 58 (2) ◽

pp. 816

Author(s):

Ed Hager

Keyword(s):

Case Studies ◽

Survey Design ◽

Asia Pacific ◽

Acquisition Time ◽

Multiple Sources ◽

Source Case ◽

On Line ◽

Seismic Data Acquisition ◽

Marine Seismic ◽

Safety And Environment

There has been a rapid uptake on the idea of using multiple sources in marine seismic data acquisition because of the additional flexibility the technique offers in survey design based not only on geophysical quality, but also for health, safety and environment (HSE) and efficiency. This paper examines three case studies conducted in Australia and Indonesia covering aspects of the advantages. An important consideration in survey design is efficiency, and multisource designs improve this by allowing wider spreads to be towed, so more data is acquired per vessel pass. In turn, HSE exposure is decreased by reducing survey times and by reducing the amount of in-sea equipment. The Trepang Survey carried out for Ophir Energy offshore West Papua was designed for efficiency, but the HSE aspect came to the fore when large amounts of floating debris (several hundred tree trunks) were found in the path of the survey vessel. By reducing the acquisition time, the risk the timber posed was minimised. The Cygnus survey in the Vulcan sub-basin is an example of where the multisource technique increased quality by improving the cross-line resolution and increasing fold without decreasing efficiency. Bianchi and Hockey were two surveys in the same area and, because the surveys were small, they were inefficient to acquire because much of the time was spent on line changes. The operator Quadrant used the fact that a triple-source design would allow for symmetrical bins to be acquired and joined the two small surveys together: effectively two sets of line change times were turned into acquisition time.

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FAULT PATTERN AND ACTIVE DEFORMATION OF OUTER ARC RIDGE OF NORTHWEST OF SIMEULUE ISLAND, ACEH, INDONESIA

BULLETIN OF THE MARINE GEOLOGY ◽

10.32693/bomg.26.1.2011.33 ◽

2016 ◽

Vol 26 (1) ◽

pp. 41 ◽

Cited By ~ 3

Author(s):

Haryadi Permana ◽

K. Hirata

Keyword(s):

Thrust Fault ◽

Active Deformation ◽

Area 3A ◽

Deformation Processes ◽

Dip Angle ◽

Marine Seismic ◽

Bathymetric Map ◽

High Degree ◽

Near Future ◽

Morphological Image

New bathymetric map of northwest Simeuleu Island area (3Â° 01â€™N-4Â°57â€™N and 93Â°16â€™E-94Â°08â€™E) has evidently illustrated fine morphological image of Outer Arc ridge and Aceh Fore Arc. The structural lineament pattern, inferred from the bathymetric map, could define in general elongated major NW-SE thrust fault complex, thrust fold, or bedding trace and N-S, NNE-SSW, WNW-ESE or ENE-WSW and E-W structural lineament trend. High intensity deformation processes related to high degree obliquity subducted plate was represented by rough and sigmoidal morphological shape, landward and steep to very steep dip angle of bedding plan. Rough morphology, V to U shape valley, dissected ridge and circular shape of landslide trace are common morphology features of active deformation zone. In the near future, high resolution marine seismic will be planned across this area to capture and confirm the subsurface structure configuration and fault movement. Keyword: bathymetric map, Outer Arc ridge, thrust fault, thrust fold, bedding trace, sigmoidal morphological, V to U shape valley,and landslide. Peta batimetri baru di sebelah barat laut Pulau Simelue (3Â° 01â€™LU - 4Â°57â€™LU and 93Â°16â€™BT-94Â°08â€™BT), memperlihatkan citra morfologi yang halus pada punggungan busur luar dan busur depan Aceh. Pola kelurusan struktur mengacu pada peta batimetri, dibagi dalam komplek sesar naik yang berarah umum baratlaut - tenggara, lipatan, atau jejak perlapisan dengan kecendrungan arah struktur utara-selatan, utara timur laut â€“ selatan barat daya, barat - barat daya, timur tenggara atau timur laut - barat daya dan timur - barat. Proses deformasi intensitas tinggi berkaitan dengan derajat kemiringan penunjaman yang tinggi, diwakili oleh bentuk morfologi sigmoid dan kasar, ke arah darat dicirikan oleh kemiringan bidang lapisan terjal hingga sangat terjal. Bentuk morfologi kasar seperti bentuk lembah V hingga U, punggungan yang terpotong dan bentuk melingkar dari jejak longsoran merupakan gambaran morfologi umum dari zona deformasi aktif. Dalam waktu dekat, seismik laut resolusi tinggi akan direncanakan memotong daerah ini untuk menggambarkan dan mengkonfirmasi konfigurasi struktur bawah permukaan dan pergerakan sesar. Kata kunci : peta batimetri, punggungan busur luar, sesar naik, lipatan, jejak bidang perlapisan, morfologi sigmoid, bentuk lembah V hingga U,dan longsoran.

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Spectrophotometric reductions with an IBM 1620

Symposium - International Astronomical Union ◽

10.1017/s0074180900053328 ◽

1966 ◽

Vol 24 ◽

pp. 116-117

Author(s):

P.-I. Eriksson

Keyword(s):

Astronomical Data ◽

Spectrophotometric Data ◽

Electronic Computers ◽

The University ◽

Near Future

Nowadays more and more of the reductions of astronomical data are made with electronic computers. As we in Uppsala have an IBM 1620 at the University, we have taken it to our help with reductions of spectrophotometric data. Here I will briefly explain how we use it now and how we want to use it in the near future.

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Recent developments in automated Transmission Electron MI

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152203 ◽

1989 ◽

Vol 47 ◽

pp. 46-47

Author(s):

W.J. de Ruijter ◽

P. Rez ◽

David J. Smith

Keyword(s):

Image Analysis ◽

Computer Image ◽

Lens Design ◽

Computer Image Analysis ◽

Transmission Electron ◽

Resolution Electron ◽

Recent Developments ◽

On Line ◽

Routine Procedures ◽

Near Future

There is growing interest in the on-line use of computers in high-resolution electron n which should reduce the demands on highly skilled operators and thereby extend the r of the technique. An on-line computer could obviously perform routine procedures hand, or else facilitate automation of various restoration, reconstruction and enhan These techniques are slow and cumbersome at present because of the need for cai micrographs and off-line processing. In low resolution microscopy (most biologic; primary incentive for automation and computer image analysis is to create a instrument, with standard programmed procedures. In HREM (materials researc computer image analysis should lead to better utilization of the microscope. Instru (improved lens design and higher accelerating voltages) have improved the interpretab the level of atomic dimensions (approximately 1.6 Å) and instrumental resolutior should become feasible in the near future.

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DNA methylation in satellite repeats disorders

Essays in Biochemistry ◽

10.1042/ebc20190028 ◽

2019 ◽

Vol 63 (6) ◽

pp. 757-771 ◽

Cited By ~ 4

Author(s):

Claire Francastel ◽

Frédérique Magdinier

Keyword(s):

Dna Methylation ◽

Human Genome ◽

Repetitive Dna ◽

Dna Sequences ◽

Satellite Repeats ◽

Tremendous Progress ◽

Genes Encoding ◽

Dna Elements ◽

Near Future

Abstract Despite the tremendous progress made in recent years in assembling the human genome, tandemly repeated DNA elements remain poorly characterized. These sequences account for the vast majority of methylated sites in the human genome and their methylated state is necessary for this repetitive DNA to function properly and to maintain genome integrity. Furthermore, recent advances highlight the emerging role of these sequences in regulating the functions of the human genome and its variability during evolution, among individuals, or in disease susceptibility. In addition, a number of inherited rare diseases are directly linked to the alteration of some of these repetitive DNA sequences, either through changes in the organization or size of the tandem repeat arrays or through mutations in genes encoding chromatin modifiers involved in the epigenetic regulation of these elements. Although largely overlooked so far in the functional annotation of the human genome, satellite elements play key roles in its architectural and topological organization. This includes functions as boundary elements delimitating functional domains or assembly of repressive nuclear compartments, with local or distal impact on gene expression. Thus, the consideration of satellite repeats organization and their associated epigenetic landmarks, including DNA methylation (DNAme), will become unavoidable in the near future to fully decipher human phenotypes and associated diseases.

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Agreeableness, Conflict Resolution Tactics, and School Behavior in Second Graders

Journal of Individual Differences ◽

10.1027/1614-0001/a000199 ◽

2016 ◽

Vol 37 (3) ◽

pp. 145-151 ◽

Cited By ~ 2

Author(s):

Daniel L. Gadke ◽

Renée M. Tobin ◽

W. Joel Schneider

Keyword(s):

Conflict Resolution ◽

Problem Behaviors ◽

Second Graders ◽

Adaptive Behaviors ◽

Second Grade ◽

School Behavior ◽

Multiple Sources ◽

School Based ◽

Second Grade Students ◽

Negotiation Tactics

Abstract. This study examined the association between Agreeableness and children’s selection of conflict resolution tactics and their overt behaviors at school. A total of 157 second graders responded to a series of conflict resolution vignettes and were observed three times during physical education classes at school. We hypothesized that Agreeableness would be inversely related to the endorsement of power assertion tactics and to displays of problem behaviors, and positively related to the endorsement of negotiation tactics and to displays of adaptive behaviors. Consistent with hypotheses, Agreeableness was inversely related to power assertion tactics and to displays of off-task, disruptive, and verbally aggressive behaviors. There was no evidence that Agreeableness was related to more socially sophisticated responses to conflict, such as negotiation, with our sample of second grade students; however, it was related to displays of adaptive behaviors, specifically on-task behaviors. Limitations, including potential reactivity effects and the restriction of observational data collection to one school-based setting, are discussed. Future researchers are encouraged to collect data from multiple sources in more than one setting over time.

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