By Franko Ćorić, PhD
University of Zagreb, Faculty of Humanities and Social Sciences
Department of Art History

In 2020 central Croatia was struck by about a dozen earthquakes around and above magnitude 5 on the Richter scale, and at the time this article was written, there had already been over two thousand aftershocks of smaller or greater intensity.

The City of Zagreb, in and around which more than a quarter of the population of Croatia live, was struck by a magnitude 5.5 earthquake on 22 March 2020, at 6:24 a.m. It happened in the early hours of that Sunday morning when there were not yet many people or church-goers in the streets; this was also the day after complete lockdown had gone into effect due to the coronavirus pandemic. Of the approximately 25,000 buildings inspected by the end of June, 20% were found temporarily—and 5.28% completely—unusable. The gables, roofs and chimneys, and structures of numerous private and public buildings as well as those of many religious buildings in the historic center, were damaged. Most of these buildings had been built or reconstructed after the devastating earthquake of 1880 (6.3 Richter) but before the 1960s, when earthquake protection became compulsory and the standard for all new construction (after the earthquakes in Makarska in 1962, Skopje in 1964 and Banja Luka in 1969).

The pandemic slowed the clearing and inspection of structures. For security reasons, firefighters demolished many architectural elements of the mostly historicist buildings, and their temporary protection was more an exception than the rule. It was not until September that the reconstruction act was passed and a multidisciplinary coordination body set up for the post-earthquake reconstruction of the city, which experts advocated. Although a strong earthquake had been expected in Zagreb, little had been done to prevent earthquake damage to historic buildings. Much of the destruction was the result of non-maintenance and poor management of the city and buildings and partly also of extensions and adaptations. Earthquake reinforcement in residential buildings was a particularly complicated topic due to ownership relations and population structure. The displays in some museums ignored that Zagreb was in a seismically active region.

The area in and around the town of Petrinja was struck by a magnitude 5 earthquake on 28 December 2020, at 6:28 a.m., which was the announcement for the more devastating earthquake of magnitude 6.2 which occurred the next day at 12:19 p.m. This region also suffered considerable destruction during the Homeland War. Its heritage mostly dates from the 18th and 19th centuries (St. Mary Magdalene’s Church in Sela near Sisak should be noted) and is mainly built of brick and mortar, a technology that does not withstand earthquakes stronger than 5.5 Richter. Traditional wooden houses rocked seriously but survived the earthquakes unscathed. Buildings in Zagreb, which had been damaged in the March earthquake, suffered additional injury in the Petrinja earthquakes (the baroque interior of St. Catherine’s Church, the interior of St. Mark’s Church and that of the Church of Christ the King, Mirogoj cemetery).

Current priorities are temporary weather protection, supporting and strengthening. The Ministry of Culture, like in April, is mobilizing conservators from all parts of the country to record the damage. Experts who participated in similar ventures in central Italy will also come to help evacuate works of art and provide temporary protection.

We must add that the Croatian authorities and cultural institutions were not prepared for earthquakes, but that they have coped in a difficult situation. The losses would have been much smaller had the protocols and standards of earthquake protection been followed. Let us hope that the experience gained will be a warning to other institutions in the country, especially in the south, where existing seismic maps and experiences suggest that even more devastating earthquakes can be expected.

More information on donating funds and materials can be found on the IIC-Croatian Group Facebook page here: https://www.facebook.com/IIC.hrvatska.grupa/

And you can donate to the Croatia Earthquake Relief Fund here: https://charity.gofundme.com/o/en/campaign/croatian-earthquake-relief-fund

(Read the article in the February-March 2021 "News in Conservation" Issue 82 p. 6-7)