annual 2010/2011 of the croatian academy of engineering - HATZ

Annual 2010/2011 of the Croatian Academy of Engineering 11
Geodetic Contribution to the Geodynamic Research
of the Area of the City of Zagreb
B. Pribičević, D. Medak, and A. Đapo
University of Zagreb,
Faculty of Geodesy
email: {bpribic, dmedak, adapo}@geof.hr
ABSTRACT
Paper presents 11 year long interdisciplinary research of geodynamic processes of the area
of the City of Zagreb. The Geodynamic GPS-Network of the City of Zagreb represents the
longest and the most intensive research effort in the eld of geodynamics in Croatia. Since
the establishment of the Network in 1997, several series of precise GPS measurements
have been conducted on specially stabilized points of Geodynamical Network of City of
Zagreb with purpose of investigation of tectonic movements and related seismic activity of
the wider area of the City of Zagreb. The Network has been densied in 2005 in the most
active region of northeastern Mount Medvednica. Since then, several GPS campaigns have
been conducted. Processing of observation data was done with scientic software GAMIT/
GLOBK, developed by MIT. From this series of GPS measurements geodetic model of
tectonic movements has been created. In the area of interest, independent geological investigations
have been conducted through even longer period of time which resulted in
geological model of tectonic movements. The correlation coefcient between geodetic and
geologic model has been calculated and shows high degree of correlation thus giving credibility
to both methods of research. Systematic analysis has been conducted over geodetic
and geologic results giving as a result unique interdisciplinary model of crust movements
over wider Zagreb area. This interdisciplinary interpretation of obtained geodetic movements
leads to a new scientic insight about geodynamics of the City of Zagreb area. The
results of this scientic research will be used to delineate zones of potential earthquake
hazard or tectonically caused landslides.
Keywords: geodesy, GPS, geodynamics, GAMIT, tectonics
Introduction
It has been known for a long time that the wider area of Zagreb is geodynamically active,
(Prelogovi, Cvijanovi 1981) (Kuk et al. 2000), (Kuk et al. 2000a), (Tomljenovi, 2002)
however, there were no data on the actual size of those movements, nor on their spatial orientation.
The rst geodetic research in this direction was made through the implementation
of the project the “Basic GPS network of the City of Zagreb” (oli et al. 1999) (Medak,
Pribievi 2001).
Through the realization of the project “Basic GPS-Network of the City of Zagreb” in 1997,
Croatian capital got a modern, geodetic foundation of high accuracy. Network was planned
as the basis for investigations of tectonic movements and related seismic activity of the
wider area of the City of Zagreb. Basic part of the network consists of 43 specially stabilized
geodetic points to meet the specic criteria for geodynamic points. After the second
series of GPS measurements in year 2001, the network has become “Geodynamic Network
of the City of Zagreb” (Medak, Pribievi 2001), (Medak, Pribievi 2002), (Medak,