Andrija Mohorovicic
(1857-1936)
by Dragutin Skoko
Andrija Mohorovicic was a prominent Croatian scientist in the field of
meteorology and seismology at the end of the nineteenth and in the early
twentieth century.
He was born on 23 January 1857 in Volosko near Opatija, where he went to
elementary school. He attended secondary school in Rijeka and studied
mathematics and physics at the Faculty of Philosophy in Prague in 1875.
After graduating, he first taught in grammar school in Zagreb
(1879-1880)
and then secondary school in Osijek. On 1 November 1882 he began to
teach at the Nautical School in Bakar, where he remained for 9 years. In
1891 he was transferred to the secondary school in Zagreb at his own
request, and on 1 January 1892 he became the head of the Meteorological
Observatory on Gric in Zagreb. In 1893 he became the doctor of
philosophy at
the Zagreb University. Soon after he was habilitated as private docent,
and in
1910 became titular associate university professor. From 1893 to 1917/18
he
taught subjects in the fields of geophysics and astronomy at the Faculty
of
Philosophy in Zagreb. In 1893 he became corresponding member, and in
1898 full member of what was then the Yugoslav Academy of Sciences and
Arts in Zagreb. At the end of 1921 he retired, and he died in December
1936. He is buried at the Mirogoj Cemetery in Zagreb.
Work in the Nautical School in Bakar was crucial for the beginning of
Andrija Mohorovicic's scientific work. This is where he first came into
direct
contact with meteorology, which he taught at the Nautical School, and
which
absorbed him to such a degree that he founded a meteorological station
in
Bakar in 1887.
When he became head of the Meteorological Observatory in Zagreb (1892)
he concentrated on three fields. He gave a scientific interpretation of
some
meteorological phenomena. In 1901 he was appointed head of the complete
meteorological service of Croatia and Slavonia, which he raised to a
European level in personnel and equipment. And finally, he gradually
extended the activities of the observatory to other fields of
geophysics:
seismology, geomagnetism and gravitation.
In March 1892 Mohorovicic began the astronomical observation of stars
passing through the Gric meridian to establish the precise time. At the
beginning of April 1893 he established a network of stations for
following
thunder storms, and in 1899 he founded hail-defence stations in the
Jaska
District. At the beginning of 1899 he started a project for research
into and
harnessing of the energy of the bura in the karst region, because
"...this
would be so beneficial for our barren littoral".
A. Mohorovicic showed interest in extraordinary meteorological phenomena
like the tornado near Novska in 1892, and the vijor (whirlwind) near
bazma
in 1898. He studied the climate in Zagreb, and in his last paper in
meteorology (1901) he discussed the decrease in atmospheric temperature
with height.
After the turn of the century Mohorovicic's scientific interest focused
exclusively on the problems of seismology. Analyzing the Pokuplje (Kupa
Valley)
earthquake of 8 October 1909, he advanced insight into the spreading of
seismic waves of earthquakes with shallow depths through the Earth.
In these studies he was the first in the world to establish, on the
basis of
seismic waves, a surface of velocity discontinuity that separates the
crust of
the Earth from the mantle and which was named the Mohorovicic
Discontinuity in his honour. Soon after Andrija Mohorovicic, scientists
confirmed the existence of this discontinuity under all the continents
and
oceans.
Mohorovicic's thoughts and ideas were truly visionary and came to
expression many years later (the effects of earthquakes on buildings,
harnessing the energy of the bura, models of the Earth, deep-focus
earthquakes, hail defence, locating earthquake epicentres, seismographs,
etc.). The well-known Swedish seismologist M. Bath included Andrija
Mohorovicic among the 13 most outstanding seismological researchers in
the
period from 1900 to 1936.
On 19 December 1936, a day after the death of Andrija Mohorovicic, the
Zagreb paper Novosti published the following article: "The scientist
Professor Andrija Mohrovicic, member of the Yugoslav Academy of
Sciences and Arts, one of the founders of modern seismology, has died.
He
was a well-known and respected figure in Zagreb, and his scientific work
in
the field of seismology gained him world recognition. He is today
considered one
of the founders of modern seismology in the world. Doctor Mohorovicic
raised the meteorological observatory in Zagreb from modest beginnings
to a
completely equipped modern institute that enjoyed world renown,
especially
in seismic measurements. He also organized the meteorological service in
Croatia and Slavonia. At the beginning of his scientific career Doctor
Mohorovicic devoted most of his energy to meteorology, but he had most
success in the field of seismology and he founded the so-called Zagreb
School of world recognition in this field of science."
Article submitted by Prof. Dr. Marijan Herak.