IAG Resolutions adopted

at the XXIth General Assembly in Boulder


The International Association of Geodesy,

Recognizing that tide gauge records are essentially relative measurements,

Endorses the proposal to fix them in a geodetic reference frame so as to decouple land from ocean effects, especially those of low frequency (e.g. signales related to climate change).

Recommends that vertical positionning be of sub-centimetre accuracy within this framework, and

Requests relevant agencies aim to ensure that this specification is met directly on site through continuous GPS measurements, or through compatible coastal connections of equivalent accuracy.

Sponsored by E. Groten as chairperson of SSG 5.149


The International Association of Geodesy,

Endorses progress made in adjusting international vertical control networks,

Recognizes the significant advance in mathematical models of ocean circulation since geodetic and oceanic leveling were last compared,

Recommends continued detailed comparison of mean sea level slopes - calculated from high resolution ocean circulation models - with those obtained from adjusted heights in a vertical geodetic network and

Requests responsible agencies to provide necessary support for these comparisons to be thoroughly investigated and reported

Sponsored by E. Groten as chairperson of SSG 5.149


The International Association of Geodesy,

Recognizing the effort in organizing gravity measurements over a network of existing and future superconduction gravimeters supplemented periodically by absolute gravimeters,

Supports the establishment group identified of a six-year observation period for the global gravity monitoring network.

Sponsored by Marson on behalf of the International Gravity Commission (Graz 1994)


The International Association of Geodesy,

Recognizing that :

(a) the vast areas of East Asia and the Pacific Basin have not yet been subjected to such close geophysical investigation as that carried out in other areas of the world;

(b) large parts of this region are heavily populated and are experiencing rapid economic growth ;

(c) the tectonic character of the region is complex and inadequately understood;

(d) the region is at extreme risk from tectonic, volcanic, seismic and other natural hazards ; and

noting that :

(a) precise geodetic measurements using space and terrestrial techniques give an effective means of monitoring tectonic, volcanic, seismic, and environmental conditions over great spatial and temporal ranges;

(b) the IAG/COSPAR Commission on International Coordination of Space Techniques for Geodesy and Geodynamics (CSTG) has been established to facilitate and coordinate global and regional work in the field of space geodesy and geodynamics;

(c) cooperation between governements, insitutions and individuals is essential for large-scale scientific investigations which an lead to the mitigation of the effects of natural disasters,

(d) in this conneciton the September 1994 UNESCO expert symposium held in Beijing on Space Technology and Applications for Sustainable Development, resolved that;

"An Asian-Pacific space geodynamic project is recommended to be established to promote and corrdinate related activities in the region as well as encourage international cooperation in order to provide more basic information for earthquake predictin, volcanic eruptions and sea-level rise."

(e) the Asian Pacific Space Geodynamic Initiative is a proposal which conforms to this resulotion :

Recommends that :

(a) this project be supported by local institutions and international coopetating agencies ;

(b) the relevant space geodetic (such as Satellite Laser Ranging, Very Long Baseline Interferometry, Global Positioning SDystem and Dynthetic Apertune Radar) and terrestrial techniques (such as gravimetry, tide gauge measurmenet, meteorological observation) be employed in support on fhis project;

(c) steps be taken to improve regional communication in support of these activities;

(d) the data acquired by the project be made available for general scientific purposes.

Sponsored by Shu-Hua Ye


The International Association of Geodesy,

Recognizing that :

(a) the geodynamics of the continent of Africa are of high scientific interest;

(b) the region is in the early stages of economic growth, and

noting that;

(a) bilateral agreements, such as in the ADOS campaign which IAG coordinated, have proved a successful vehicle for cooperation in the past ;

(b) Kenya has embarked on a project to monitor the current crustal movements in the Kenyan segment of the East African Rift-Valley;

(c) Tunisia and France are cooperating on a geodynamic study to evaluate seismic risk in the Gafsa region in Souhern Tunisia;

recommends that ;

(a) bilateral agreements on geodynamic projects should be encouraged and supported by the Africal community of nations as leading to scientific progress for the continent as a whole;

(b) these projects be supported by local institutions and by interntional cooperating agencies;

(c) the relevant space geodetic and terrestrial techniques be employed in support of these projects;

(d) steps be taken to improve regional communication in support of these activities;

(e) the data ecquired by the project be made available for general scientific purposes.


The International Association of Geodesy,

Noting :

that France and the Institut Geographique National have provided indispensable support and efficient administration of the Association by operating the Central Bureau over the whole period from 1919 to 1995 under the responsibility of the following Secretaries General and Assistant Secretaries General :

G. Perrier

P. Tardi

G. Laclavère

J.J. Levallois

M. Louis

C. Boucher

P. Willis


to these friends and coleagues the grateful thanks of the Association for all that they have done to keep the organization alive, healthy and changing with the times.


The International Association of Geodesy,


that the preparations by the Americal Geophysical Union and by the University of Colorado at Boulder have combined to make the XXIst General Assembly of the IAG in Boulder, from 2 to 14 July 1995, a remarkable and unforgettable occasion.

Extends :

To Jean Dickey, the Organizing Committee and supporting staff its grateful thanks for all that they ave done to make this possible, in particular the willing and friendly assistance of the staff in the IAG office at Baker Hall has been outstanding.