1 / 28

Bureau Gravimetrique International ( BGI) R ole and Services to Terrestrial Gravimetry

Bureau Gravimetrique International ( BGI) R ole and Services to Terrestrial Gravimetry S . Bonvalot , G . Balmino , F. Reinquin , A . Briais , G. Gabalda , L. Seoane Bureau Gravimetrique International ( BGI) Toulouse , France H. Wilmes , H. Wziontek

aliza
Download Presentation

Bureau Gravimetrique International ( BGI) R ole and Services to Terrestrial Gravimetry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bureau Gravimetrique International (BGI) Roleand Services to TerrestrialGravimetry S. Bonvalot, G. Balmino, F. Reinquin, A. Briais, G. Gabalda, L. Seoane Bureau Gravimetrique International (BGI)Toulouse, France H. Wilmes, H. Wziontek Federal Agency for Cartography and Geodesy (BKG)Frankfurt/Leipzip, Germany IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  2. Objectives / Partnerships • Compilation, validation & long term archiving of gravimetric data • Aims at facilitating the diffusion of gravity information to the scientific community • French supporting organizations  13 Institutions & Universities • International collaborations (mostly within IAG/IGFS frame)  some examples • BKG Germany Absolute gravimetry Int. Geoid ServiceNewton’s Bulletin International schools CU AustraliaWorld Gravity Map BIPMAbsolute gravimetry NGA, USA World Gravity Map IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  3. Main activities • Global databases & products  Relative & absolute gravity measurements • Gravity modeling  Ex :World Gravity Map • Software developments  Gravity analysis, modeling, terrain correction… • Field surveys  Relative & Absolute (Europe, South America, Africa, Asia…) • Education / Summer schools Collab. With IGeS • IAG commission & working groups in gravimetry IGFS, GGOS, CCM-BIPM, etc. • Instrumentation  Support fromFrench teams for a future cold atom gravimeter (AQG by MuQuans) • Focus here on main data & products recently provided by BGI IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  4. Overview of the global gravity databases Relative land measurements (a few millions of data) Relative marine measurements (> 10millions of data) Reference stations IGSN71 / Potsdam networks (>4500 stations) Absolutemeasurements (started in 2007) Consultation / Requestfrom the BGI website http://bgi.obs-mip.fr IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  5. Absolute Gravity database • Joint operation by BKG and BGI since 2007as a contribution to IAG / IGFS • Motivation • Increasing number of AG instruments  few µGal level measurements in lab& field • Need to register AG measurements and to share information globally • Scientific interest / Benefits • Reference network for relative gravity surveys & relative meter calibration • Support and registry for inter-comparisons of AG instruments • Study of static and temporal gravity changes / Link to other geophysical observations • New International GravityReference System(replacement of IGSN71) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  6. Absolute Gravity database • Web-based user interface developed in 2008Available at 2 mirrored sites : BKG: http://agrav.bkg.bund.de/agrav-meta/ • BGI : http://bgi.obs-mip.fr • Overview about stations, observation, epochs, gravimeters and institutions • Who measured ? Where and When ? • Provision of contact information • Sharing results (gravity values) • Data repository and long term availability • Upload of data done by users using their own ‘project’-files (ask for login) Currentstatus of thedatabase - 08/2013768 stations / 2607 observations / 45 instruments / 41 institutions (24 countries) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  7. Absolute Gravity database New web application AGrav is under development at BKG Similar structure but new functionalities • Improved functionalities • New interactive map (OpenStreetMap) • Clustering of stations • Classification of available networks • Plot of gravity time series • Report generator • Bibliographic references to related publications • … (Wziontek et al., 2013, 17th International Symposium on Earth Tides, Warsaw, Poland) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  8. Absolute Gravity database New web application AGrav is under development at BKG Relation of AG and SC (GGP) stations (Wziontek et al., 2013, 17th International Symposium on Earth Tides, Warsaw, Poland) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  9. Absolute Gravity database New web application AGrav is under development at BKG • Link to SG data (common sites) • Data structure compatible to GGP • Possibility of download SG time series • Plots of SG/AG time series • … (Wziontek et al., 2013, 17th International Symposium on Earth Tides, Warsaw, Poland) Expected to make better reliability between AG and SG observations IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  10. World Gravity Map (WGM) • Project initiated in 2008 • Collaboration with the Commission for the Geological Map of the World (CGMW) • Initially aimed at providing worldwide Bouguer & Isostatic anomalies • Contribution to the global geological & geophysical mapsedited by CGMW / UNESCO for education and research purposes • (extensively used in geophysical interpretation but usually computed at regional scale) • Challenging project  providing new global products • Based on rigorous and homogeneous computation of anomalies in spherical geometry • Including global high resolution terrain corrections (1 arc-minute) • Using up-to-date global models for gravity (EGM08, DTU10) and topography IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  11. World Gravity Map (WGM) • Proposed approach (analytic approach : Spherical Harmonic) • Computation of the whole terrain effect (Bouguer shell + Terrain Corrections) • Based on new developments by G. Balmino to perform SHA/SHS (up to d/o 32600) • See : Balminoet al. (Jounal of Geodesy, 2012) • Geodetic definition • High resolution computations (d/o 10800) • Realistic Earth model(all surface masses ) • Continents • Oceans • Innersears – Lakes • Ice caps IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  12. World Gravity Map (WGM) Surface masses taken into account(according to their position w.r.t. mean sea level) Densities (kg/m3) Crust (2670) Upper Mantle (3270) Ocean water (1027) Ice (917) Data sources ETOPO1 (surface & bedrock) SRTM30 ILEC Data base Closed seas Aral sea Caspian sea Dead sea Lakes Baikal Balkach Bear lake Constance Erie Eyre Huron Ladoga Leman Malawi Maracaibo Michigan Onega Salton Slaves Superior Tanganyka Tiberiade Titicaca Victoria Winnipeg Yssyk-Koul Lands Oceans Land b.s.l. Chott Algeria-Tunisia Qattara (depression) DeathValley Netherlands (part) Turfan (depression) Ice shelves Ross Ronne-Filchner, Larsen, Amery Ice caps Over Greenland Over Antarctica IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  13. World Gravity Map (WGM) Computation of gravity contribution of surface masses (derived from ETOPO1) Lands / Oceans / Inlandseas & major lakes / Ices (Antarctica, Greenland) 1’x1’ grid of spherical terrain corrections(applicable to any observed gravity field) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  14. World Gravity Map (WGM) Spherical complete Bouguer anomaly (based on EGM08 / DTU10 gravity models) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  15. World Gravity Map (WGM) Spherical complete isostatic anomaly (Airy-Heiskanen) (based on EGM08 / DTU10 gravity models) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  16. World Gravity Map (WGM) Free-air anomaly (Molodensky) (based on EGM08 / DTU10 gravity models) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  17. World Gravity Map (WGM) Free-air anomaly (Molodensky) (based on EGM08 / DTU10 gravity models) • Version 1.0 (WGM2012) achieved in 2012Bonvalotet al. (World GravityMap, 2012) ; Balmino et al. (Jounal of Geodesy, 2012) • Set of 3 spherical anomalies (Bouguer, Isostatic, surface free-air)Distributed by CGMW / UNESCO: http://ccgm.free.fr • Digital grids of anomalies downloadable at 2’x2’ : http://bgi.obs-mip.fr • On-line tool for grid extraction and visualisation • Upgraded versions as soon as new EGM is available (including GOCE and new surface data) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  18. Other work in progress • WGM2012 gravity anomalies and global tectonic map (in progress) • Information derived from the global tectonic map • Tectonic plates • Major geological units & ages (oceanic crust, continental crust) • Major faults (thrust, subduction, transform…) • Sedimentary basins, igneous and effusive rocks, etc… IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  19. Other work in progress • WGM2012 gravity anomalies and global tectonic map (in progress) Betterinterpretation / teaching of the Earth’sgravity anomalies at large scale IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  20. Other work in progress • Interactive application for 3D view (based on NASA World Wind) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  21. Other work in progress • Interactive application for 3D view (based on NASA World Wind) WGM2012 Complete Bouguer anomaly IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  22. Other work in progress • Interactive application for 3D view (based on NASA World Wind) WGM2012 free-air anomaly IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  23. Other work in progress • Interactive application for 3D view (based on NASA World Wind) WGM2012 complete Isostatic anomaly IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  24. Other work in progress • Interactive application for 3D view (based on NASA World Wind) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  25. Other work in progress • Interactive application for 3D view (based on NASA World Wind) Gravity anomalies and global tectonics (in progress) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  26. Recent on-line Tools • Prediction of gravityat a given site  theoretical & interpolated values Requests for metrology purpose needing an estimation of the local gravity IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  27. Recent on-line Tools • On-line availability of « old » BGI Bulletins collection (1959-2002) Achieved in August 2013 (containsinternalmatters + contributingpapers) IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

  28. Conclusions / Perspectives • To provide relevant services to IAG scientific users • Global gravity database : Compilation / Re-processing of surface gravity data • Global / Regional gravity modeling : Including surface and GOCE data • Earth’s Reference Gravity System : Contribution to the realization of the future system • Active collaborations in progress within IGFSBKG (Germany), IGeS (Italy), NGA (USA), DTU (Denmark), CU (Australia)… • Information update from users is still very welcome ! • With surface gravity observations (land & marine surveys) – Products from airborne surveys ? • With absolute gravity measurements (FG5, A10 or others) • With any software, documentationbelieved to be useful for other scientists Feel free to contact BGI ! bgi@cnes.fr BGI : http://bgi.obs-mip.fr BKG: http://agrav.bkg.bund.de/agrav-meta IAG Symposium on Terrestrial Gravimetry : Static and Mobile Measurements – September 1 7– 20, 2013 – St Petersburg, Russia

More Related