Subject: IAG reorganization Date: Thu, 02 May 2002 10:11:53 -0500 From: "Clark R. Wilson" To: feissel@ensg.ign.fr, zerbini@df.unibo.it, v.dehant@oma.be, dmc@maia.usno.navy.mil, rsg@mail1.jpl.nasa.gov, gambis@obspm.fr, bernard.ducarme@oma.be, groten@ipgs.ipg.verm.tu-darmstadt.de, plw@unixa.nerc-bidston.ac.uk, bevis@soest.hawaii.edu, takemoto@kugi.kyoto-u.ac.jp, farias@bipm.org, clarkw@maestro.geo.utexas.edu, Ben Chao , Gerhard Beutler Dear Colleagues: here is a proposal for the new IAG Commission 3 (Earth Rotation and Geodynamics) along with explanatory comments on its relationship to Section V under the current IAG structure. I invite your comments on this proposal: As discussed at the IAG reorganization planning meeting on April 26, new Commission 3 Earth Rotation and Geodynamics, replaces Section V Geodynamics in the current structure. Activities not proposed to be included in the two subcommissions below are proposed to be assigned as follows: The present International Earth Tide Commission is proposed to be assigned to new Commission 2; Activities of the present Fundamental Parameters special commission will be assigned to a new Inter-Commission Committee which will report its results via the IERS Conventions; The services (IERS, PMSL, ICET, BIPM time division) will acquire representation on a level with Commissions in the IAG executive committee. Commission 3 is proposed to consist initially of two subcommissions: Subcommission 1: Crustal Deformation This proposed subcommission includes activities now under Commission XIV in the current IAG structure. The present Subcommission XIV contains sub-units related to particular geographical regions, including long-standing projects such as WEGENER, APSG, and the Central European Initiative, as well as Africa and Antarctica. The objectives of the current Commission XIV (described on its website http://www.df.unibo.it/commXIV/) are proposed to continue: First, to study 3-D motions, in active tectonic regions, post-glacial rebound and sea-level fluctuations and changes in relation to vertical tectonics along many parts of the coastlines and in relation to environmental fluctuations/changes affecting the geodetic observations; Second, to promote, develop and coordinate international programs related to observations, analysis and data interpretation for the three fields of investigation mentioned above; Third to promote the development of appropriate models. Subcommission 2: Earth Orientation and Global Geophysical Fluids This proposed subcommission includes activities within the IERS Global Geophysical Fluids Centers (GGFC). There are 7 special bureaus organized to examine the influence of the earth's mobile constituents (fluids) on the earth's orientation, defined broadly in terms of length of day, polar motion, nutations, geocenter and gravity. The 7 special bureaus are concerned with estimating influences of the core, mantle, oceans, terrestrial hydrology, atmosphere, and ocean tides. Activities under the present Special Commission 8 (Sea Level and Ice Sheets) are expected to be incorporated within the appropriate special bureaus. This proposed subcommission will follow the current goals of the GGFC (taken from the GGFC website http://bowie.gsfc.nasa.gov/ggfc/): to compute time variations of angular momenta and related torques, gravitational coefficients, and geocenter shift for all geophysical fluids based on global observational data, and/or products from state-of-the-art models, and to conduct scientific sessions at international meetings and conferences. Best Regards, Clark R. Wilson Wallace Pratt Professor of Geophysics Department of Geological Sciences Institute for Geophysics Center for Space Research University of Texas at Austin Austin TX 78712 Phone 512-471-5008 FAX 512-471-9425