In May and June, intensive field research is underway near Štanjel, where the team is studying one of the most significant active geological structures in Slovenia—the Raška Fault. It stretches all the way from the Goriška Brda region through the Vipava Valley, Branik, Štanjel, along the Raša Valley, through Senožeče, Vremščica, and all the way to Ilirska Bistrica. The Raška Fault is capable of generating stronger earthquakes, so we are interested in how often such earthquakes occur. To this end, we are searching for seismic deformations in young sediments deposited across the fault and studying them in detail.

Paleoseismological excavation into the sediments above an active fault is used to study the records of past earthquake and to estimate their magnitude (based on the size of the deformation) and age, leading to an understanding of the fault's seismic history, which is key to understanding its future seismic potential. At the current excavation site, we are investigating the contact between fluvial sediments from the Raša stream and alluvial fan deposits from a nearby ravine. Within the trench we have found clear evidence of past earthquakes, which we will date through further laboratory analyses.

To find out more about how earthquakes affect the natural environment, see lecture by Dr Petra Jamšek Rupnik (from 28:30 minutes onwards).