S-wave velocity images of the Dead Sea Basin provided by ambient seismic noise |
| |
| Institution: | 1. Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA;2. Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China;3. Colorado Center for Astrodynamics Research, The University of Colorado Boulder, UCB 431, Boulder, CO 80309-0431, United States;4. Department of Computer Science, University of Rochester, Rochester, NY 14627, USA;5. Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA;6. Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur,CNRS C.S. 34229, Nice Cedex 4, 06304, France;1. Department of Mathematics, Hong Kong Baptist University, Hong Kong, China;2. School of Mathematical Sciences, Shanghai Jiao Tong University, Shanghai 200240, China;3. Department of Applied Mathematics, The Hong Kong Polytechnic University, Hong Kong, China;4. Department of Mathematics, School of Science, Hangzhou Dianzi University, Hangzhou 310018, China;5. Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China |
| |
| Abstract: | Based on passive seismic interferometry applied to ambient seismic noise recordings between station pairs belonging to a small-scale array, we have obtained shear wave velocity images of the uppermost materials that make up the Dead Sea Basin. We extracted empirical Green’s functions from cross-correlations of long-term recordings of continuous data, and measured inter-station Rayleigh wave group velocities from the daily correlation functions for positive and negative correlation time lags in the 0.1–0.5 Hz bandwidth. A tomographic inversion of the travel times estimated for each frequency is performed, allowing the laterally varying 3-D surface wave velocity structure below the array to be retrieved. Subsequently, the velocity-frequency curves are inverted to obtain S-wave velocity images of the study area as horizontal depth sections and longitude- and latitude-depth sections. The results, which are consistent with other previous ones, provide clear images of the local seismic velocity structure of the basin. Low shear velocities are dominant at shallow depths above 3.5 km, but even so a spit of land with a depth that does not exceed 4 km is identified as a salt diapir separating the low velocities associated with sedimentary infill on both sides of the Lisan Peninsula. The lack of low speeds at the sampling depth of 11.5 km implies that there are no sediments and therefore that the basement is near 10–11 km depth, but gradually decreasing from south to north. The results also highlight the bowl-shaped basin with poorly consolidated sedimentary materials accumulated in the central part of the basin. The structure of the western margin of the basin evidences a certain asymmetry both whether it is compared to the eastern margin and it is observed in north–south direction. Infill materials down to ∼8 km depth are observed in the hollow of the basin, unlike what happens in the north and south where they are spread beyond the western Dead Sea shore. |
| |
| Keywords: | Ambient seismic noise Correlation Dispersion Tomography Depth-dependent shear velocity models Dead Sea |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
