ISSN:
1365-246X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
Notes:
Seismic refraction and wide-angle reflection studies were carried out in the Bengal basin, India. Trace normalized record sections were produced from the digital data recorded in this sedimentary basin. The most significant feature observed in these seismograms is the presence of high-energy later arrivals which appear in arcuate shapes with their curvatures concave downwards. These arrivals are identified as free-surface reflected refractions (or multiple diving waves), which belong to the family of free-surface multiples. The nature and generation of these waves are demonstrated with the help of synthetic examples. It is found that the presence of high-velocity gradients in the top layers is a necessary prerequisite for the generation of these high-energy multiple diving waves. These later arrival multiples, along with the other primary phases present on the observed record section from the Bengal basin, have been used to prepare a well-constrained velocity model. The results bring out the presence of very high-velocity gradients (∼0.3–1.0 km s−1 km−1) in the sedimentary layers of the Bengal basin, which are an order of magnitude higher than those obtained in other sedimentary basins of India.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-246X.1995.tb06452.x
