1. Crustal Model Validation in the Mediterranean Sea.
- Author
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Laske, Gabi, El-Sharkawy, Amr, and Meier, Thomas
- Subjects
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MODEL validation , *RAYLEIGH waves , *PHASE velocity , *SEISMIC tomography , *GROUP velocity - Abstract
It has been two decades since the publication of the 5-degree global crustal model CRUST5.1in 1998. More recently, the 1-degree model CRUST1.0 was released for wide use in 2013.The more recent model was based on a comprehensive, updated database of crustal structureinformation from active source experiments as well as receiver function studies, Moho depthmaps from regional seismic tomography and, in some instances, results from gravity studies.A change in strategy to compile CRUST1.0 also was an iterative model validation andsubsequent update to fit global surface wave dispersion data. Yet, in an attempt to updateCRUST1.0 to the final version, some discrepancies with surface wave constraints remained.This project zooms in on the Mediterranean Sea and compares model predictions withobservations. CRUST1.0 subsequently was used as a starting model to compile a global model of theentire lithosphere, LITHO1.0 that was released in 2014. This model is based on surfacewave data alone, with an updated and larger database that includes proprietarydata in the Eastern Mediterranean/Asia Minor area. While intermediate-period(40 – 29 s) Rayleigh wave phase velocity is well-explained by CRUST1.0, groupvelocities are underpredicted in the western Mediterranean and overpredicted inthe eastern Mediterranean, by up to nearly 10%. Both CRUST1.0 and LITHO1.0fail to model Love wave group velocities adequately, even at long periods (T> 50s). Recently, new surface wave constraints collected around the Mediterranean area allowtomographic imaging to unprecedented detail. The extension to shorter periods than what isavailable on global scale allows assessment of structure not only on the crust in general butalso in areas with thick sediment cover, such as the Nile Delta in the eastern Mediterranean.At this level, we validate the 1997 Laske and Masters global sediment model that wasadopted into CRUST1.0. [ABSTRACT FROM AUTHOR]
- Published
- 2019