The Croatian government began repairing sinkholes that carved out an agricultural region near the capital, causing panic among villagers who saw them grow – in number and size.
The sinkholes made a dramatic appearance in early January, less than a week after a 6.4 magnitude earthquake struck central Croatia on December 29 last year, killing seven people.
Encouraging headlines around the world including the references to “Swiss cheese”, a hundred chasms have appeared around the towns of Mecencani and Borojevici, to the south-east of the capital, Zagreb.
The largest sinkholes were nearly 30 meters (98 feet) in diameter.
The “bumper crop” of sinkholes is unusual in that earthquakes and other seismic events usually do not cause them. However, in areas where groundwater has eroded the bedrock below to a point where it can no longer support the soil above, sinkholes appear.
Stjepan Terzic, chief engineer of the National Geological Service of Croatia, said that while sinkholes are a normal phenomenon, their high concentration “in such a small place” is unusual, but the shocks caused by the earthquake accelerated their appearance.
“Thus, in a short time, many holes appeared for which, under normal conditions, decades or even longer periods would be necessary,” he told AFP news agency.
Seismologist Josip Stipčević, Department of Geophysics, University of Zagreb, Recount Total Croatia News The earthquakes the country is experiencing are the result of the movement of tectonic plates beneath the surface, with the large Eurasian plate colliding with the smaller Adriatic plate – a fragment of the larger African plate.
Since the beginning of the 20th century, Croatia has experienced nine earthquakes with a magnitude greater than 6.
Repairs to fill the sinkholes began last week and are expected to last a month and a half.