Development of a seafloor geophysical sledge

Davis, Angela; Bennell, J. D.; Huws, D.; Thomas, D

doi:10.1080/10641198909379862

Cited by 11 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The source is a refinement of a simple operating principle originally used by Schwarz and Conwell (1974) and then subsequently developed by the University of Wales, Bangor (Davis et al, 1989) whereby a high voltage electromagnetic hammer imparts a horizontal force relative to the seabed. The use of impulsive sources such as a sledge mounted airgun (Ewing et al, 1992) to generate S h waves was found to also produce significant S v and P wave energy.…”

Section: Sourcementioning

confidence: 99%

“…Richardson et al (1991) used an approach whereby bender elements were directly inserted into soft sediment to measure the shear wave velocity between transmitter and receiver probes. Davis et al (1989) describes the development of a seafloor shear wave refraction system capable of acquiring refraction profiles at discrete points along a survey line. Unlike alternative systems, it was able to measure the lateral variability in the topmost sediments over large distances.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Acquisition and inversion of Love wave data to measure the lateral variability of geo-acoustic properties of marine sediments

Winsborrow

Huws

Muyzert

2003

Journal of Applied Geophysics

View full text Add to dashboard Cite

Section: Sourcementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Acquisition and inversion of Love wave data to measure the lateral variability of geo-acoustic properties of marine sediments

Winsborrow

Huws

Muyzert

2003

Journal of Applied Geophysics

View full text Add to dashboard Cite

“…The system and deployment procedures have been described in Davis et al (1989Davis et al ( , 1991 so only a brief summary is given here.…”

Section: Data Acquisitionmentioning

confidence: 99%

A Nondestructive Technique for Predicting the In Situ Void Ratio for Marine Sediments

Huws

Davis

Pyrah

2000

Marine Georesources & Geotechnology

View full text Add to dashboard Cite

“…Other authors document the use of refraction techniques whereby shear waves are directly generated at the sea‐floor and detected using sea‐floor‐coupled geophones (Schwarz and Conwell 1974; Gehrmann, Gimpel and Theilen 1984; Stoll et al . 1988; Davis et al . 1989).…”

Section: Introductionmentioning

confidence: 99%

The estimation of shear‐wave statics using in situ measurements in marine near‐surface sediments

Winsborrow

Huws

Muyzert

2005

Geophysical Prospecting

View full text Add to dashboard Cite

A B S T R A C TShear-wave statics in marine seismic exploration data are routinely too large to be estimated using conventional techniques. Near-surface unconsolidated sediments are often characterized by low values of V s and steep velocity gradients. Minor variations in sediment properties at these depths correspond to variations in the shear-wave velocity and will produce significant static shifts. It is suggested that a significant proportion of the shear-wave statics solution can be estimated by performing a separate high-resolution survey to target near-surface unconsolidated sediments. Love-wave, shear-wave refraction and geotechnical measurements were individually used to form high-resolution near-surface shear-wave velocity models to estimate the shear-wave statics for a designated survey line. Comparisons with predicted statics revealed that shear-wave statics could not be estimated using a velocity model predicted by substituting geotechnical measurements into empirical relationships. Empirical relationships represent a vast simplification of the factors that control V s and are therefore not sufficiently sensitive to estimate shear-wave statics. Refraction measurements are potentially sensitive to short-wavelength variations in sediment properties when combined with accurate navigational data. Statics estimated from Love-wave data are less sensitive, and sometimes smoothed in appearance, since interpreted velocity values represent an average both laterally and vertically over the receiver array and the frequency-depth sensitivity range, respectively.For the survey site, statics estimated from near-surface irregularities using shearwave refraction measurements represent almost half the total statics solution. More often, this proportion will be greater when bedrock relief is less. I N T R O D U C T I O NThe resolution of commercial marine shear-wave data is routinely decreased by the presence of large static shifts. Static shifts are raypath-specific delays in traveltimes that are introduced into seismic data by either bedrock relief or nearsurface irregularities (e.g. surface topography, lateral velocity variations, the presence of a low-velocity layer). More often, however, it is a combination of these factors. The magnitude of *

show abstract

Development of a seafloor geophysical sledge

Cited by 11 publications

References 6 publications

Acquisition and inversion of Love wave data to measure the lateral variability of geo-acoustic properties of marine sediments

Acquisition and inversion of Love wave data to measure the lateral variability of geo-acoustic properties of marine sediments

A Nondestructive Technique for Predicting the In Situ Void Ratio for Marine Sediments

The estimation of shear‐wave statics using in situ measurements in marine near‐surface sediments

Contact Info

Product

Resources

About