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Department of Geophysics, Faculty of Science, University of Zagreb
Department of Earth Science, University of Bergen


Investigation of
seismically vulnerable areas in Croatia and
seismic ground motion assessment


17 January 2022 – 30 April 2024


Project manager
Assoc. prof. Snježana Markušić

Andrija Mohorovičić Geophysical Institute, Department of Geophysics, Faculty of Science, University of Zagreb, Croatia

Project assistant
Assist. prof. Josip Stipčević

Andrija Mohorovičić Geophysical Institute, Department of Geophysics, Faculty of Science, University of Zagreb, Croatia

Norwegian project partner
Prof. Stéphane Rondenay

Department of Earth Science, University of Bergen, Norway

Project administrator
Branimir Turudić

Andrija Mohorovičić Geophysical Institute, Department of Geophysics, Faculty of Science, University of Zagreb, Croatia


The overall objectives

The objective of the project is to facilitate development and modernization of seismic hazard assessment in Croatia and provide knowledge and tools, such as updated maps and models, for the development of seismic risk reduction policies through improved scientific infrastructure, increased capacity building and knowledge transfer, including communication with policymakers and other stakeholders and international research cooperation. The project aims to be an important contribution to making Croatian society more resilient to the impact of destructive earthquakes.


The specific objectives

Specific objectives of the project are:

  • assess the potential seismic hazard for selected seismically most endangered region(s) in Croatia;
  • build a new seismic research infrastructure for the highest scientific impact;
  • strengthen the collaboration between Croatian and Norwegian geophysical communities through joint research and knowledge transfer;
  • transfer the scientific understanding about the seismic and natural hazards to the community, people, businesses, policymakers and government agencies;
  • contribute to earthquake risk reduction.

This project proposal consists of two main scientific components and implementation of all actions specified in each part is necessary in order to increase the seismic safety of the Republic of Croatia. Both components are focused on some of the most seismically endangered areas of Croatia. The aforementioned activities complement each other and are equally important in the process of better seismic hazard assessment and thus seismic risk reduction. More specifically, these investigations are of great importance as their results can help national authorities, public and private institutions, civil emergency agencies and urban planners to enhance their disaster preparedness plans thus contributing to the security of the Croatian citizens.

The project consists of the following components:

  • Component 1 – Assessment of seismogenic potential and characterization of the seismic fault systems and fault behaviour on the basis of newly collected data using modern seismological methods
  • Component 2 – Development of attenuation relations for predicting seismic ground motion (GMPE – ground motion prediction equation)


Component 1
(PI: Assist. prof. Josip Stipčević)

The first component aims to assess in much greater detail than previously possible the 3D crustal structure, the seismicity, fault system anatomy, tectonic stress accumulation rate, and the physics of the lithospheric forces for selected area in Croatia, among the most seismically endangered. These new insights will allow for the development of a detailed 3D model of the crust that would in return enable 3D simulations of wave propagation, and local seismic hazard assessment through earthquake shaking scenario calculation. For these purposes at least fourteen (14) seismographs or GNSS units are planned to be purchased (together with necessary IT equipment – servers, data storage, PCs, …) in order to expand the pool of seismographs in Croatia. The results of the research will be open to civil engineers, urban planners and local governments so that they can use them when planning future projects. The planned temporary seismic network can be integrated into the Croatian seismological network run by the Seismological Survey at the Department of Geophysics, Faculty of Science. This integration could prove particularly useful in the event of a strong earthquake.


Component 2
(PI: Assoc. prof. Snježana Markušić)

The second component would enable the development of hybrid-empirical attenuation relations by combining empirical data of recorded earthquakes and stochastic modelling using characteristic regional seismic parameters of the investigated areas. To successfully accomplish these tasks, it is necessary to purchase at least eleven accelerographs, 3 borehole accelerographs (for their installation 3x30 m borehole drilling is needed), one full MASW system, seven HVSR instruments and additional IT equipment (data storage, PCs, …). For seismic hazard applications, ground-motion amplitudes are often estimated using ground-motion prediction equations (GMPEs). GMPEs relate ground-motion intensity measures (GMIMs), such as peak ground acceleration (PGA), peak ground velocity, and 5% damped pseudoacceleration linear-elastic response spectral acceleration (PSA), to seismological parameters in a specified region, such as earthquake magnitude, source-to-site distance, local site conditions, and style of faulting. Accelerometric network after the end of the project, can also be integrated into the network of the Seismological Survey and/or the purchased instruments can be temporarily set up for seismic monitoring of tall buildings (built and under construction), seismic monitoring of dams before and after earthquakes or possibly leased to neighbouring countries seeking to join the EU but do not have the necessary instruments for seismic monitoring.