Empirical reflection travel time versus depth and velocity versus depth functions for the deep‐sea sediment column

Carlson, R. L.; Gangi, Anthony F.; Snow, K. R.

doi:10.1029/jb091ib08p08249

Cited by 63 publications

(66 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The subregion 1 and 2 models most closely resemble the OSss trend within this depth range. In comparison, the shallow subregion 3, 4 and 5 models most closely resemble the trend for Cretaceous and younger deep-sea sediments in predominantly abyssal plain and continental rise settings (DS; Carlson et al 1986), which was derived using borehole-to-seismic correlations at 154 global sites of the Deep Sea Drilling Program.…”

Section: Comparisons With Published Datamentioning

confidence: 99%

Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Shimeld¹,

Li²,

Chian³

et al. 2015

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YThe Canada Basin and the southern Alpha-Mendeleev ridge complex underlie a significant proportion of the Arctic Ocean, but the geology of this undrilled and mostly ice-covered frontier is poorly known. New information is encoded in seismic wide-angle reflections and refractions recorded with expendable sonobuoys between 2007 and 2011. Velocity-depth samples within the sedimentary succession are extracted from published analyses for 142 of these records obtained at irregularly spaced stations across an area of 1.9E + 06 km 2 . The samples are modelled at regional, subregional and station-specific scales using an exponential function of inverse velocity versus depth with regionally representative parameters determined through numerical regression. With this approach, smooth, non-oscillatory velocity-depth profiles can be generated for any desired location in the study area, even where the measurement density is low. Practical application is demonstrated with a map of sedimentary thickness, derived from seismic reflection horizons interpreted in the time domain and depth converted using the velocity-depth profiles for each seismic trace. A thickness of 12-13 km is present beneath both the upper Mackenzie fan and the middle slope off of Alaska, but the sedimentary prism thins more gradually outboard of the latter region. Mapping of the observed-to-predicted velocities reveals coherent geospatial trends associated with five subregions: the Mackenzie fan; the continental slopes beyond the Mackenzie fan; the abyssal plain; the southwestern Canada Basin; and, the Alpha-Mendeleev magnetic domain. Comparison of the subregional velocity-depth models with published borehole data, and interpretation of the station-specific best-fitting model parameters, suggests that sandstone is not a predominant lithology in any of the five subregions. However, the bulk sand-to-shale ratio likely increases towards the Mackenzie fan, and the model for this subregion compares favourably with borehole data for Miocene turbidites in the eastern Gulf of Mexico. The station-specific results also indicate that Quaternary sediments coarsen towards the Beaufort-Mackenzie and Banks Island margins in a manner that is consistent with the variable history of Laurentide Ice Sheet advance documented for these margins. Lithological factors do not fully account for the elevated velocity-depth trends that are associated with the southwestern Canada Basin and the Alpha-Mendeleev magnetic domain. Accelerated porosity reduction due to elevated palaeo-heat flow is inferred for these regions, which may be related to the underlying crustal types or possibly volcanic

show abstract

Section: Comparisons With Published Datamentioning

confidence: 99%

Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Shimeld¹,

Li²,

Chian³

et al. 2015

Geophysical Journal International

View full text Add to dashboard Cite

show abstract

“…The study of Volpi et al [2001], for example, shows seismic interval velocities from stacking velocities that are very different to downhole velocities measured during ODP Leg 178. Because of this, we used an empirical relation [Carlson et al, 1986] ; the RMS error in these estimates is 26 m in depth. The method successfully reproduces the generally decreasing seismic velocity with decreasing depth and has previously been applied to seismic data acquired on the western Antarctic Peninsula and Bellingshausen Sea continental rises Scheuer et al, 2006a].…”

Section: Twt [S] To Depth [M] Conversionmentioning

confidence: 99%

Gridded isopach maps from the South Pacific and their use in interpreting the sedimentation history of the West Antarctic continental margin

Scheuer

Gohl

Eagles

2006

Geochem Geophys Geosyst

View full text Add to dashboard Cite

[1] We model sediment isopach grids for the southern Pacific margin of West Antarctica on the basis of a compilation of more than 10,000 km of single-channel and multichannel seismic reflection data and correlations with ocean drilling sites. Following recent seismic stratigraphic models, we differentiate two main sequences, the upper of which alone is defined by seismostratigraphic indications for frequent grounded ice advances to the shelf edge off West Antarctica. The subsequent modeling of sediment thickness grids allows us to compare the pre-glacially dominated and glacially dominated sedimentary development of the study area. On the basis of available age constraints from drilling sites, we assume the onset of accumulation of sediments on the continental rise that were supplied by frequent advances of grounding ice on the continental shelf to have occurred at about 10 Ma. The thickest glacial sediment accumulations occur in front of major glacial drainage outlets, i.e., Marguerite Trough on the western Antarctic Peninsula margin, Belgica Trough in the Bellingshausen Sea, and a depression on the inner and middle shelves off Pine Island Bay in the Amundsen Sea. Glacially dominated sedimentation rates of between 140 and 170 m/m.y. are calculated for these sites.

show abstract

“…This close correspondence testifies to the care and insight of the shipboard scientists in analyzing the cores . Based on the detailed lithostratigraphy revealed by the log and by using a statistical model relating depth to traveltime in deep-sea sediments (Carlson et al, 1986), we have also made a detailed correlation of seismic reflectors with lithologic boundaries at Site 418. Of the five reflectors considered, three correspond to events also described by Senske and Stephen (this volume), and all can be correlated with lithologic boundaries.…”

Section: Discussionmentioning

confidence: 99%

“…Using depths calculated from the model of Carlson et al (1986) and referring to the coring and logging records, we correlate these reflectors with the lithostratigraphy as follows.…”

Section: Correlation With the Seismic-reflection Recordmentioning

confidence: 99%

“…Finally, they correlate the blue reflector with the top of igneous basement, although the estimated depth is 290 mbsf, as opposed to the 324 mbsf depth to basement found by drilling. Carlson et al (1986) have made a statistical analysis of reflection times and depths to 233 reflecting horizons at 154 DSDP sites. The results indicate that depths can be predicted to within 13 mbsf (rms error) for traveltimes less than about 0.4 s and to within 37 mbsf for traveltimes between 0.4 and about 1.3 s by an empirical equation…”

Section: Correlation With the Seismic-reflection Recordmentioning

confidence: 99%

See 1 more Smart Citation

Correlations of Sediment Lithostratigraphy, Downhole Logs, and Seismic Reflectors at Site 418

Carlson¹,

Wilkens²,

Broglia³

1988

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

We have correlated the spectral gamma-ray log from the 324-m sediment section at Hole 418A with core data from Holes 418A and 418B to develop a more detailed lithostratigraphic model for Site 418 and a more precise correlation of lithologic boundaries with seismic reflections. In general, log-unit boundaries can be resolved to within about 1 m (below seafloor). Except for lithologic Unit III, all units defined by coring are well defined by the logs and depths to unit boundaries defined by logging are consistent with constraints imposed by the cores. The logs also indicate the existence of several subunits not defined by coring. Each of five reflectors correlates with a unit boundary. In particular, reflectors at 0.21 and 0.29 s (two-way traveltime, below seafloor), which have been identified as horizon A c and horizon 0 by Senske and Stephen (this volume), correlate with the base of the Eocene clays of Unit IV and with the top of the "black clay" sequence, Unit VI.

show abstract

Empirical reflection travel time versus depth and velocity versus depth functions for the deep‐sea sediment column

Abstract: Numerous correlations of one-way only if the variation of seismic velocity with reflection travel times and depths to reflecting depth is known. outline our statistical models and methods. tant correlation criterion. Other reliable criteria (all of which imply changes of physical

Cited by 63 publications

References 23 publications

Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Gridded isopach maps from the South Pacific and their use in interpreting the sedimentation history of the West Antarctic continental margin

Correlations of Sediment Lithostratigraphy, Downhole Logs, and Seismic Reflectors at Site 418

Contact Info

Product

Resources

About