HISTORY OF SEISMOLOGY IN CROATIA

The work of Andrija Mohorovicic (1857-1936) had a large impact on the development of seismology, both in Croatia and world-wide. This paper presents a chronological survey of the development of seismology in Croatia providing context for the discovery of the Mohorovicic discontinuity in 1910. The development of early Croatian seismology was strongly influenced by advances in the field made in both Europe and world-wide. It also was influenced by several strong earthquakes that occurred within its territory, most notably the 1880 Zagreb earthquake, and the 1909 Kupa Valley (Pokupsko) earthquake. By studying the seismograms from the Kupa Valley earthquake, Mohorovicic was able to prove the existence of the boundary layer between the Earth's crust and the mantle (the Mohorovicic discontinuity). After Mohorovicic retired in 1921, seismological research in Croatia lost much of it's momentum, and for 20 years no seismological papers were published. After World War II, the Geophysical Institute was incorporated into the Faculty of Science of the University of Zagreb, and seismologists became active once more. Beginning in the second half of the twentieth century, the scientific interests of Croatian seismologists broadened, and international cooperation intensified. During that time, the number of active seismologists in Croatia varied, but never exceeded twelve, all of whom were affiliated with the Department of Geophysics of the Faculty of Science at the University of Zagreb. This small seismological community bore the responsibility of maintaining high standards in seismological research and education, and of keeping Croatian seismology visible in the world of geophysical sciences.