3D model of the crust
The preliminary 3D model of the Earth’s crust (Figure 1) for the Northern and Central Dalmatia describes the approximate structure of the Earth’s interior and has been assembled for the purpose of conducting earthquake simulations.
Figure 1. 3D model of the crust for the Northren and Central Dalmatia. The values of P-wave velocities (VP) are displayed in various cross-sections s1-s8.
The model covers area of 275 km x 290 km and extends to a depth of 80 km. It consists of four main structural units: sediments (deposited during the Messinian-Pleistocene and Eocene-Messinian cycles), carbonates, crystalline crust and mantle (Figure 2).
Figure 2. Boundaries of the main structural units comprising the 3D model and depiction of the top of the model (P-wave velocities, VP).
Resolution of the model is 500 m x 500 m x 500 m and for each element values of P- and S-wave velocities as well as the medium’s density are provided. The thicknesses of individual layers and the values of parameters within them (Table 1) are defined based on research as follows:
- Brocher (2005) – relations for calculating S-wave velocities and density.
- Brocher (2008), Oldenburg and Jones (2017) – values of P-wave velocities.
- Fantoni and Franciosi (2010) – thickness of sediments.
- Stipčević et al. (2020) – Moho depths.
- Zailac et al. (2023) – thickness of carbonates.
Table 1: Values of P-wave velocity (Vp), S-wave velocity (Vs), and density (ρ) of individual layers comprising the seismic 3D model.
|
|
Sediments |
Carbonates |
Crystalline crust |
Mantle |
|
Vp (m/s) |
1700 – 3800 |
4200 – 6000 |
7000 |
8000 |
|
Vs (m/s) |
429 – 2115 |
2443 – 3549 |
3998 |
4613 |
|
ρ (kg/m3) |
1754 – 2365 |
2421 – 2716 |
2968 |
3291 |
Topography data was obtained from the OpenTopography server and bathymetry data from EMODnet. A 3D visualization of the model is available through the ParaView Glance (download the corresponding glance file – 30.4 MB).
Literature:
Brocher, T.M. (2008) Compressional and shear-wave velocity versus depth relations for common rock types in Northern California. Bulletin of the Seismological Society of America 98(2): 950–968.
Brocher, T.M. (2005) Empirical relations between elastic wavespeeds and density in the Earth’s crust. Bulletin of the Seismological Society of America 95(6): 2081–2092.
Fantoni, R., Franciosi, R. (2010) Tectono-sedimentary Setting of the Po Plain and Adriatic Foreland. Rendiconti Lincei – Scienze Fisiche e Naturali, 21, S197-S209. http://dx.doi.org/10.1007/s12210-010-0102-4
Oldenburg, D.W., Jones F.H.M. (2017). Geophysics for Practicing Geoscientists: Physical Properties, Seismic Velocity. https://gpg.geosci.xyz/content/physical_properties/seismic_velocity_duplicate.html
Stipčević, J., Herak, M., Molinari, I., Dasović, I., Tkalčić, H., Gosar, A. (2020) Crustal Thickness Beneath the Dinarides and Surrounding Areas From Receiver Functions. Tectonics, 37, 1-15, https://.org/10.1029/2019TC005872
Zailac, K., Matoš, B., Vlahović, I. i Stipčević, J. (2023). Referent seismic crustal model of the Dinarides. https://urn.nsk.hr/urn:nbn:hr:217:793485
