# International Union of Geodesy and Geophysics

The International Union of Geodesy and Geophysics (IUGG; French: Union géodésique et géophysique internationale, UGGI) is an international non-governmental organization dedicated to the scientific study of Earth and its space environment using geophysical and geodetic techniques. The IUGG is a member of the International Science Council (ISC), which is composed of international scholarly and scientific institutions and national academies of sciences.

## History

The IUGG was established in Brussels, Belgium in 1919.

## Objectives

IUGG's objectives are the promotion and coordination of studies related to Earth's physical, chemical and mathematical representation. This includes geometrical shape, internal structure, gravity and magnetic fields, seismicity, volcanism, hydrologic cycle, glaciers, oceans, atmosphere, ionosphere, and magnetosphere of Earth. It also includes solar, lunar and planetary studies. Some areas within its scope are environmental preservation, reduction of the effects of natural hazards, and mineral resources.

## Structures

The IUGG consists of eight semi-autonomous associations:
* International Association of Cryospheric Sciences (IACS)
* International Association of Geodesy (IAG)
* International Association of Geomagnetism and Aeronomy (IAGA)
* International Association of Hydrological Sciences (IAHS)
* International Association of Meteorology and Atmospheric Sciences (IAMAS)
* International Association for the Physical Sciences of the Oceans (IAPSO)
* International Association of Seismology and Physics of the Earth's Interior (IASPEI)
* International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI)
It has also established six commissions to promote interdisciplinary problems:
* Climatic and Environmental Changes (CCEC)
* Mathematical Geophysics (CMG)
* Geophysical Risk and Sustainability (GRC)
* Study of the Earth's Deep Interior (SEDI)
* Data and Information (UCDI)
* Planetary Sciences (UCPS)
and the Union Working Group on History.

## General Assemblies, Presidents, and Secretaries General

List of General Assemblies, Presidents, and Secretaries-General.
| Nr. | Year | General Assembly in | General Assembly in | President | President | President | Secretary-General | Secretary-General | Secretary-General |
| 28. | 2023 | Berlin | Germany | 2023-2027 | Chris Rizos | Australia | | | |
| 27. | 2019 | Montreal | Canada | 2019-2023 | Kathryn Whaler | United Kingdom | 2019-2023 | Alexander Rudloff | Germany |
| 26. | 2015 | Prague | Czech Republic | 2015-2019 | Michael Sideris | Canada | 2015-2019 | Alik Ismail-Zadeh | Germany / Russia |
| 25. | 2011 | Melbourne | Australia | 2011-2015 | Harsh Gupta | India | 2011-2015 | Alik Ismail-Zadeh | Germany / Russia |
| 24. | 2007 | Perugia | Italy | 2007-2011 | Tom Beer | Australia | 2007-2011 | Alik Ismail-Zadeh | Germany / Russia |
| 23. | 2003 | Sapporo | Japan | 2003-2007 | Uri Shamir | Israel | 2003-2007 | JoAnn Joselyn | United States |
| 22. | 1999 | Birmingham | United Kingdom | 1999-2003 | Masaru Kono | Japan | 1999-2003 | JoAnn Joselyn | United States |
| 21. | 1995 | Boulder | United States | 1995-1999 | P.J. Wyllie | United States | 1995-1999 | Georges Balmino | France |
| 20. | 1991 | Vienna | Austria | 1991-1995 | Helmut Moritz | Austria | 1991-1995 | Georges Balmino | France |
| 19. | 1987 | Vancouver | Canada | 1987-1991 | V.I. Keilis-Borok | Soviet Union | 1987-1991 | Baron Paul Melchior | Belgium |
| 18. | 1983 | Hamburg | West Germany | 1983-1987 | D. Lal | India | 1983-1987 | Baron Paul Melchior | Belgium |
| 17. | 1979 | Canberra | Australia | 1979-1983 | G.D. Garland | Canada | 1979-1983 | Baron Paul Melchior | Belgium |
| 16. | 1975 | Grenoble | France | 1975-1979 | A. Ashour | Egypt | 1973-1979 | Baron Paul Melchior | Belgium |
| 15. | 1971 | Moscow | Soviet Union | 1971-1975 | H. Charnock | United Kingdom | 1973-1991 | Baron Paul Melchior | Belgium |
| 14. | 1967 | Zurich | Switzerland | 1967-1971 | J. Coulomb | France | 1967-1973 | G.D. Garland | Canada |
| 13. | 1963 | Berkeley | United States | 1963-1967 | J. Kaplan | United States | 1963-1967 | G.D. Garland | Canada |
| 12. | 1960 | Helsinki | Finland | 1960-1963 | V.V. Beloussov | Soviet Union | 1960-1963 | G.R. Laclavère | France |
| 11. | 1957 | Toronto | Canada | 1957-1960 | J.T. Wilson | Canada | 1957-1960 | G.R. Laclavère | France |
| 10. | 1954 | Rome | Italy | 1954-1957 | K.R. Ramanathan | India | 1954-1957 | G.R. Laclavère | France |
| 9. | 1951 | Brussels | Belgium | 1951-1954 | S. Chapman | United Kingdom | 1951-1954 | G.R. Laclavère | France |
| 8. | 1948 | Oslo | Norway | 1948-1951 | F.A. Vening Meinesz | Netherlands | 1946-1951 | J.M. Stagg | United Kingdom |
| 7. | 1939 | Washington DC | United States | 1946-1948 | B. Helland-Hansen | Norway | 1939-1946 | H. St. J.L. Winterbotham | United Kingdom |
| 6. | 1936 | Edinburgh | United Kingdom | 1936-1942 | D. La Cour | Denmark | 1936-1939 | H. St. J.L. Winterbotham | United Kingdom |
| 5. | 1933 | Lisbon | Portugal | 1933-1936 | W. Bowie | United States | 1933-1936 | H. St. J.L. Winterbotham | United Kingdom |
| 4. | 1930 | Stockholm | Sweden | 1919-1933 | C. Lallemand | France | 1930-1933 | H. St. J.L. Winterbotham | United Kingdom |
| 3. | 1927 | Prague | Czechoslovakia | 1919-1933 | C. Lallemand | France | 1927-1930 | Sir Henry Lyons | United Kingdom |
| 2. | 1924 | Madrid | Spain | 1919-1933 | C. Lallemand | France | 1924-1927 | Sir Henry Lyons | United Kingdom |
| 1. | 1922 | Rome | Italy | 1919-1933 | C. Lallemand | France | 1919-1924 | Sir Henry Lyons | United Kingdom |