Andrija Mohorovičić

Andrija Mohorovičić [a ː ndria mɔhɔrɔʋitʃitɕ ] ( born January 23, 1857 in Volosko Opatija, † December 18, 1936 in Zagreb) was a Croatian meteorologist and geophysicist. He succeeded in 1909 for the first time to detect the interface between Earth's crust and mantle with earthquake waves.

Life

Mohorovičić 1875-1879 studied in Prague, Mathematics and Physics, among others, Ernst Mach. Subsequently, he was a teacher at a high school and at the Nautical School in Bakar near Rijeka. There he founded in 1887 a meteorological observatory. In 1891 he was in Zagreb ( Agram ) Professor at the Technical Secondary School and director of the State Institute for Meteorology and Geodynamics. In 1892 he received his doctorate with a meteorological work at the University of Zagreb.

Since 1900, but his main interest was in seismology, because on the Balkan peninsula earthquakes are frequent. The observatory had received a seismograph after an earthquake in 1880, which was but imperfectly. After a strong earthquake in 1901 succeeded in the acquisition of more powerful tools and a astatic pendulum of Emil Wiechert. 1910 discovered Mohorovičić on seismograms of the earthquake of Pokupsko near Zagreb on 8 October 1909 that some P- and S- quake waves arrived later than expected. He concluded that they were bent at a border in about 54 km depth. Later studies confirmed this interface as a global phenomenon: At a depth of 30-50 km of the mantle begins with a temperature of around 600 ° C.

This isolated area later called Mohorovičić discontinuity and is now often abbreviated in the geosciences with " Moho ". Within the lithosphere, the outer shell of the earth, this interface separates the crust from the outer layer of the upper mantle. Ten years after the peak of his activity as a seismologist joined Mohorovičić 1921 in retirement. After his death he was buried in the Mirogoj cemetery in Zagreb. After him the asteroid ( 8422 ) Mohorovičić is named.

Mohorovičić is the father of the physicist and geophysicist Stjepan Mohorovičić (1890-1980), a physics teacher at a school in Zagreb, still remembered, as he predicted in 1934 the existence of positronium ( in the Astronomische Nachrichten ). He also said a Mohorovičić discontinuity on the moon before, which was also found by the measurements of the Apollo astronauts. Overall, Andrija Mohorovičić had four sons.