Lithospheric structure beneath the Dinarides

We investigate the structure of the lithosphere beneath the Dinarides using the receiver function method. Seismic discontinuities in the Earth’s crust and upper mantle cause the conversion of body waves, transforming P-waves into S-waves and vice versa. By analyzing the converted phases on the surface, we can determine the depth of these discontinuities.

Figure 1. Map of the locations of the used seismic stations in receiver function analysis.

In this study, we used 123 seismic stations from 11 different seismic networks, as shown in Figure 1. We analyze data from 1234 teleseismic events that occurred from the beginning of 2016 to April 2023. The P and S receiver functions were computed for all records at the stations and stacked at common conversion points. An example of the calculated receiver functions for the seismic station STON is presented in Figure 2.

Figure 2. P and S receiver functions calculated for seismic station STON. Positive amplitudes are marked red and negative blue.

Preliminary results of the receiver function analysis for the broader Dinaric region are displayed through two profiles in Figure 3. The most prominent feature is a clear, shallow, positive phase (at approximately 40 km depth on profile AA’), which corresponds to the boundary between the crust and the mantle, i.e., the Moho discontinuity.

Figure 3. P receiver functions  stacked at common conversion points and shown along two profiles: AA’ and BB’. Positive amplitudes are marked red and negative blue. The profile locations are indicated in the upper-right image.

A follow-up analysis of receiver functions is planned for the beginning of 2024, using the seismograms from newly installed stations within the CRONOS project in Dalmatia. With this additional data, we aim to refine our results and gain a clearer understanding of these discontinuities, building on the insights already gained.

Prepared by Dr. Tena Belinić Topić