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| Titel |
Appreciation of scientific achievements of Jozef Hus. |
| VerfasserIn |
S. Spassov, R. Geeraerts |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023226
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| Zusammenfassung |
| In 2004, the Geophysical Centre of the Royal Meteorological Institute of Belgium (RMIB) in
Dourbes (south Belgium) celebrated its 50th anniversary. Fifty years of top research
to which Jozef Hus contributed considerably. When he started his career in this
governmental institution more than 40 years ago, palaeomagnetic research was absent at the
RIMB.
After finishing studies in condensed matter physics at Ghent University (Belgium) in
1963, he became an assistant at the RMIB and developed with Prof. Dr. A. De Vuyst, in
charge of the geomagnetic observatory, a method for absolute measurements of all
geomagnetic field elements with a proton magnetometer. Wishing to extend the record of
geomagnetic field observations in time, Jozef began to set up a laboratory of his own and
started to construct and develop instruments for palaeomagnetic research with competence,
great enthusiasm and concentrated passion. This world-class laboratory was constructed
between 1976 ad 1980. In 1981, he received the title Doctor of Sciences from the Free
University of Brussels based on his thesis entitled “De indirecte meting van de seculaire
verandering van het geomagnetisch veld”.
Palaeomagnetism of Quaternary sediments and archaeo- and rock magnetism have been
Jozef’s most important research fields. In fact, a short sojourn in Prof. E. Thellier’s
Laboratory of Geomagnetism at Saint-Maur-de-Fossés (Paris) in 1965, raised Jozef’s interest
in archaeomagnetism. He formed a solid basis for the detailed establishment of reference
curves for declination and inclination for the Belgian territory for historical and
archaeological times. He studied the suitability of burned archaeological materials to record
the Earth’s magnetic field as well as effects which influence accurate field registration in
archaeological materials, such as magnetic refraction and magnetic anisotropy. During his
career, Jozef promoted archaeomagnetism as a valuable dating tool and strengthened the
cooperation with the archaeological community in a way that is almost unique in
Europe.
Jozef investigated loess/palaeosol deposits in Belgium, south-east Europe, central and
eastern Asia and contributed to magnetostratigraphic dating and to a better understanding of
the magnetisation process in these sediments. He mentioned for the first time that different
post detrital remanence lock-in conditions could be responsible for the inconsistently
observed stratigraphic position of the Matuyama-Brunhes boundary (MBB) on the Chinese
Loess Plateau, which not always occurs in an interglacial period as expected from marine
sediments.
Sediment formation and its progressive transformation into soil are controlled by wind
strength, temperature and humidity and alter the magnetic mineral content of the source
material. Analysing the magnetic mineral content and texture of loesses and palaeosols he
found that both lithologic units contain mainly the same magnetic mineral types, but that soil
magnetic minerals were much more oxidised and of smaller grain sizes than in loess. He
found also that the primary sedimentary fabric is in general only moderately modified in the
soils.
Jozef investigated also magnetic properties of weathering products and showed
particularly that siderite, present in marine Quaternary sediments, alters when in contact with
air forming haematite. He studied the acquisition of crystallisation magnetisation
during the transformation of a paramagnetic (in ambient temperature) mineral into a
mineral with ferromagnetic properties. He showed further that manganese could
substitute iron in the goethite crystal lattice during crystal growth, hence decreasing the
crystallinity degree. Besides the typical rock magnetic investigation for magnetic
mineral characterisation Jozef often used Mössbauer-spectroscopy to corroborate
interpretations.
Jozef also promoted rock magnetism as a service to the environmental management
community. Even, after retirement he remains active and proposed the application of
magnetic methods for pollution detection within the frame of the project “Magnetic Valley”
which aims at socio-economical development of the area around the Geophysical
Centre.
Jozef has always been searching for new applications of magnetic methods and aimed at
collaboration with scientists from different research areas such as geochemistry, geology,
archaeology and physics. Numerous transdisciplinary publications in internationally
approved journals resulted from this activity. Besides his lecturing duties at the Free
University of Brussels, he shared his experience by teaching young scientists such as for
instance at the International Post-Graduate Training course on Fundamental and
Applied Quaternary Geology and became a leading member of the European Research
Training network AARCH (Archaeomagnetic Applications for the Rescue of Cultural
Heritage).
Together with the aerial photographer Charles Léva, Jozef promoted in his free time
the application of geophysical prospection methods for searching archaeological
structures in the subsurface and determining the archaeological nature of “marks”
discovered by aerial photography. This fruitful work resulted for instance in the
investigation of the Roman road system in Belgium. Both were the founders of
the Interdisciplinary Centre for Aerial Photography and organised international
symposia.
A kaleidoscope of archaeo- and enviromagnetic topics will be presented, responding to
the cornerstones of Jozef’s successful and intensive research career as interdisciplinary
archaeo-, rock- and enviromagnetist. |
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