in recognition of his outstanding contributions to the study of Earth tides and his lifetime dedication to geodesy and geophysics

P. Melchior started his research career at the Royal Observatory of Belgium in 1949 in the field of Time measurements and Earth rotation. In 1952, shortly after he received his Ph.D. degree on the characteristics of polar motion, he joined a team working on a star catalogue from meridian observations. Published in 1969, the catalogue was adopted by the International Latitude Service as a reference on observations of polar motion. Along with the meridian observations, P. Melchior developed, in collaboration with Dr. J. Verbaandert of the Royal Observatory, a quartz horizontal pendulum for earth tides measurement; this was later installed in many countries throughout the world.

In 1966, P. Melchior published a new theory establishing a full correspondence between nutations and Earth tides; later he showed that the dynamic effects of the Earth liquid inner core, detected from Earth tides, were necessary for an improved model of the astronomical observations. The International Astronomical Union adopted his new nutation model in 1979.

Besides being an exceptional scientist, P. Melchior is an excellent organizer. In 1957 he was invited by the International Association of Geodesy to organize the International Center for Earth Tides (ICET). He became Director of ICET in 1957 and has remained in this position since then. In 1971, he was elected General Secretary of the International Union of Geodesy and Geophysics; he occupied this position until 1990; in this position he succeeded to return the Peoples Republic of China as IUGG member. He was Director of the Royal Observatory of Belgium from 1983 to 1990.

Prof. P. Melchior was elected an AGU fellow in 1978. He is a foreign member of the Academy of Sciences and Letters of Finland, the Academy of Sciences of Luxembourg, the Royal Academy of Sciences of the Netherlands, the Royal Academy of Sciences of Spain. Prof. P. Melchior is also Doctor Honoris Causa of the University Darmstadt. Recently, His Majesty the King Bouduin Belgium awarded Prof. P. Melchior the title of Baron.

Newsletter 51, 26, 1994