As part of the activities of the Green STEM project and the popularization of geophysical disciplines in our school, students who attend optional classes in Geophysics participated in a field lesson together with students of the Geophysics Department of the Faculty of Science and Mathematics in Zagreb and their professors, Assoc. Ph.D. Ivom Dasović and Ph.D. Antun Marki, who also organized the trip.
First, we visited Petrinja and toured the area affected by the 2020 earthquake, after which Assoc. Ph.D. Iva Dasović demonstrated the HSVR method, which analyzes seismic disturbance measurements, which is one of the common methods used in engineering seismology. Measurements were made at two locations in the park in Petrinja, which will be analyzed later.
After Petrinja, we visited the Lonjsko Polje Geomagnetic Observatory, established in 2012, where precise measurements of the intensity and direction of the Earth’s magnetic field have been carried out continuously for many years. The location of the observatory was chosen because it is an area without magnetic anomalies originating from the inhomogeneous distribution of ferromagnetic elements in the Earth’s crust, it is far enough from the civilized forest, and there is no fear of future urbanization. The instruments of the observatory are housed in several houses made of non-magnetic materials.
Thanks to the careful selection of the location, GO Lonjsko polje is ideal for observing geomagnetic pulsations, and at the end of 2012 it became a member of the European network EMMA (European quasi-Meridional Magnetometer Array). The data of the Observatory within the EMMA network contribute to the observation of resonances of geomagnetic forces (in almost real time), from which information on physical processes in the Earth’s magnetosphere can be obtained.
GO Lonjsko polje is led by Dr. sc. Igor Mandić, who, with the help of colleagues Dina Curman, senior technician Damir Ptičar and technician Josip Modrić, demonstrated to us the operation of the observatory and the measuring devices in it, as well as the method of data collection and analysis.








