IGN has published a new estimation of the ITRF - the International Terrestrial Reference Frame

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How is the Earth deformed under the effect of continental drift, seismic phenomena or ice cap melt? At what speed is the sea level rising? How can we calculate the position of a constantly deformed point on the surface of the Earth? In order to continue getting the replies to these fundamental questions helping to understand our planet’s dynamics, the ITRF (International Terrestrial Reference Frame) must be updated. This reference frame is calculated by IGN once every four years on average and the new estimation, the ‘ITRF2014’, improves the accuracy of the reference and provides new data on seismic movement.

IGN has just published its new International Terrestrial Reference Frame, the ‘ITRF2014’, which is based on the global observations of spatial geodesy made up until December 31st 2014. If this new estimation confirms the position of the Earth’s centre of mass as calculated in 2010, it will confirm the accuracy of the reference scale, in other words that of the distances calculated using the coordinates compared to the ITRF and it quantifies more precisely the seismic displacements caused by recent devastating earthquakes such as those that occurred in Chili in 2010 and Japan in 2011. “Thanks to ITRF2014 results, we can now calculate to within an accuracy of a few millimetres, not only co-seismic displacement but also the post-seismic trajectory of a point which has undergone a major earthquake. This new calculation of the ITRF has enabled its accuracy to be improved: we can, for example, not only base our measurements of rising sea levels on this global reference frame, an important indicator when judging climatic change, but also quantify the level of confidence we can have in these measurements”, Zuheir Altamimi, Director of research at IGN, in charge of work on the ITRF (International Terrestrial Reference Frame) for the IERS*.

The stakes involved with using the ITRF in applying Earth sciences are considerable. As a reference index for determining the satellite orbits that observe our planets, it represents an indispensable basis for scientists, astronomers, geo-physicians, climatologists the world over who study the Earth’s deformations and movements. It is also an undeniable source of information for all enthusiasts of geodesy or the evolving shape of our planet.

Read the press release of IGN (in French)

The ITRF2014 is published at the following address: http://itrf.ign.fr/ITRF_solutions/2014/

*The International Astronomical Union and the International Union of Geodesy and Geophysics created the international service for the Earth’s rotation and reference systems (IERS: International Earth Rotation and Reference System Service) in 2008. This service confided IGN with the task of providing a geodesic reference on a planetary scale: the International Terrestrial Reference Frame (ITRF) which assembles and publishes the coordinates and average speeds of some 900 spatial geodesy instruments – GPS antenna, DORIS beacons, LASER telescopes and VLBI antenna.