A doublet earthquake has hit the Croatian capital of Zagreb on Sunday morning, causing damage and injuries. According to European-Mediterranean Seismological Center the quakes occurred at 6:24 am and 7:01 local time, reaching magnitude 5.3 and 5.0. Both were centered only a few kilometers north of the Zagrebcity center. Several older buildings suffered damage. Local media report collapsed building fronts, roofs and damaged windows. A tower of the Zagreb cathedral came down and power was out in parts of Zagreb for several hours. According to reports on Sunday evening, at least 600 buildings suffered damage to various degrees. The croatian civil defense provided assistance to more than 1000 people. The damage assessment continues. 17 people in Zagreb and surrounding counties were injured, some of them remain in critical conditions.

The quake was felt widely across the northern parts of Balkan peninsila, leading to minor shaking of high-rise buildings as far as Budapest (HUN), Vienna (AUT) and Munich (GER). However, no damage was caused outside of Croatia except of a damaged bridge near the Slovenian town Maribor and a few cracked buildings in the Hungarian district Zala. Our Risklayer rapid disaster model estimated a maximum intensity of VII for parts of the Zagreb area, which is confirmed by the observed damage. Intensity V was calculated for the most-affected areas in Hungary and Slovenia.

The earthquake happened on Medvednica fault directly north of the city, which is one of several smaller thrust faults in greater Zagreb area. It is also source of most of the city’s historical seismicity, including the devastating Mw6.3 earthquake in 1880. No significant aftershocks (M4+) followed the mainshock yet (as of March 23rd, 8am UTC) although several weaker shocks were felt over the last night. Due to the shallow depth of most quakes, even very small events around magnitude 2 can be felt.