Sigsbee2A 2D Synthetic Dataset

September 25, 2001

The Subsalt Multiples Attenuation and Reduction Technology Joint Venture (SMAART JV) is releasing to the industry and universities the 2D acoustic synthetic dataset referred to as Sigsbee2A. This dataset has been previously distributed to participants in the 2001 SEG Research Workshop on Velocity Model Independent Imaging for Complex Media ( The current release includes the velocity model and allows anyone to use the data and to publish the results under the conditions described in the Data Release Agreement.

Sigsbee2A models the geologic setting found in on the Sigsbee escarpment in the deep water Gulf of Mexico as shown in Sigsbee2A Stratigraphy. The model exhibits the illumination problems due to the complex salt shape with rugose salt top found in this area. The dataset was calculated with an absorbing free surface condition and a weaker than normal water bottom reflection, i.e. the data do not contain free surface multiples and less than normal internal multiples. The color scale in this stratigraphy plot is chosen to emphasize reflectors and faults and does not represent the real velocity contrasts. A number of normal and thrust faults separate the sedimentary blocks. The syncline segments of the salt top focus reflection energy from the salt bottom and the sub salt reflections and produce non-hyperbolic arrival travel time curves.

The stratigraphic velocity model is shown in Sigsbee2A Interval Velocity. The reflection interfaces are all the result of velocity contrasts, which are fluctuations about a mean velocity V + Vo + kZ. The relative velocity fluctuation average dV/V is about 0.03, which is enough to produce reflections, but not sufficient to destroy the basic gradient macro model Sigsbee2A Migration Velocity which is used in depth migration.

For more details on the construction and numeric computation of the dataset, see the Sigsbee2A Distribution file.

This release is available via the Smaart Data Administrator. Contact the Smaart Data Administrator for prices.

To obtain the data, sign the Data Release Agreement (PDF file) and fax it to Edo Bergsma at +31 15 2783499 or mail it to:
Delft University of Technology
Faculty of Applied Sciences
Acoustical Wavefield Imaging
attn. Edo Bergsma
P.O. Box 5046
2600 GA Delft
The Netherlands.

To contact the Smaart Data Administrator, send email to

We hope you will find the data useful for current and future research.

Edo Bergsma
Smaart Data Administrator