Full-waveform inversion of short-offset, band-limited seismic data in the Alboran Basin (SE Iberia)

Content Provider	Semantic Scholar
Author	Gras, Claudia C. Dagnino, Daniel Jiménez-Tejero, Clara Estela Meléndez, Adrià Sallarés, Valentí Ranero, César R.
Copyright Year	2019
Abstract	We present a high-resolution P-wave velocity model of the sedimentary cover and the uppermost basement to ∼ 3 km depth obtained by full-waveform inversion of multichannel seismic data acquired with a 6 km long streamer in the Alboran Sea (SE Iberia). The inherent nonlinearity of the method, especially for short-offset, bandlimited seismic data as this one, is circumvented by applying a data processing or modelling sequence consisting of three steps: (1) data re-datuming by back-propagation of the recorded seismograms to the seafloor; (2) joint refraction and reflection travel-time tomography combining the original and the re-datumed shot gathers; and (3) full-waveform inversion of the original shot gathers using the model obtained by travel-time tomography as initial reference. The final velocity model shows a number of geological structures that cannot be identified in the travel-time tomography models or easily interpreted from seismic reflection images alone. A sharp strong velocity contrast accurately defines the geometry of the top of the basement. Several low-velocity zones that may correspond to the abrupt velocity change across steeply dipping normal faults are observed at the flanks of the basin. A 200–300 m thick, high-velocity layer embedded within lower-velocity sediment may correspond to evaporites deposited during the Messinian crisis. The results confirm that the combination of data re-datuming and joint refraction and reflection travel-time inversion provides reference models that are accurate enough to apply fullwaveform inversion to relatively short offset streamer data in deep-water settings starting at a field-data standard lowfrequency content of 6 Hz.
File Format	PDF HTM / HTML
DOI	10.5194/se-2019-46
Alternate Webpage(s)	https://www.solid-earth.net/10/1833/2019/se-10-1833-2019.pdf
Alternate Webpage(s)	https://doi.org/10.5194/se-2019-46
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article