Traveltime inversion strategies for wide-angle seismic traveltime; A useful algorithm: ZS92
Yung-En Yu
Abstract
Traveltime inversion has been developed nearly 20 years. The adventage of inversion is the ability to obtain a final model quickly, handle large data sets and derive simpler models for a given level of fit to the data. In the recent year, several big seismic experiments get a lot of wide-angle data sets. Therefore, be using the inversion rather than the forward modeling can easier and faster to derive a velocity model.
This report presents different strategies for modeling seismic refraction/wide-angle reflection traveltime to obtain 2-D velocity model. But first, it discusses about some pre-modelling considerations. The considerations are about the quality of the data, the picking of arrival traveltim and the importance of the building up the start model. Then, the report discusses the modeling strategies. It describes the best modeling strategies according to (1) the model parametrization, (2) the inclusion of prior information, (3) the complexity of the earth structure, (4) the characteristics of the data, and (5) the utilization of coincident seismic reflection data.
Last, the report presents a useful algorithm: ZS92. This inversion scheme can use the refraction and reflection to derive the 2-D velocity and interface structure. And the algorithm is suited for multishot crustal seismic data, so it is commonly used in many investigations of the wide-angle seismic experiment.
Reference
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Zelt, C. A. & Smith, R. B., Seismic traveltime inversion for 2-D crustal velocity structure, Geophys. J. Int. (1992) 108,16-34
(Abstract)(Full text)
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