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Impact of GOCE on lithospheric modelling in active plate margins. ESA Living Planet Symposium 2013 Edinburgh, 10-09-2013. Michael Hosse (1) , Roland Pail (1) , Martin Horwath (1) , Tetjana Romanyuk (1) , Ben Gutknecht (2) , Nils Köther (2)
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Impact of GOCE on lithospheric modelling in active plate margins ESA Living Planet Symposium 2013 Edinburgh, 10-09-2013 Michael Hosse(1), Roland Pail(1), Martin Horwath(1), Tetjana Romanyuk(1), Ben Gutknecht(2), Nils Köther(2) (1) Technische Universität München, Institute of Astronomical and Physical Geodesy(2) Christian-Albrechts-Universitaet Kiel, Institute of Geosciences, Department of Geophysics
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 About IMOSAGA • Integrated Modelling of Satellite and Airborne Gravity data of Active plate margins • Part of DFG programme „Mass transport and mass distribution in the Earth system“ SPP 1257 • Tight cooperation and interaction of geodetic and geophysical expert groups
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Project Objectives • Investigation of active continental margins for • Density distribution in 3D • Dynamic Structures (Finite Elements) • Rigidity • by usage of • Satellite gravimetry and gradiometry (GOCE, GRACE) • Terrestrial gravimetry • Combined gravity models (Least Squares Collocation LSC)
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Motivation revised gravity field information in geophysically interesting areas impact on static and dynamic lithospheric models (Götze et al., 2011)
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Datasources – Terrestrial data • ~ 175000 pointmeasurements (gabs, FA, BA) from different sourcescollectedduringthepast 30 years • widelyspreadover South America • Noinformationsavailableaboutusedinstrumentsandmethods • Noaccuraciesavailable
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Datasources – Digital Terrain Model Used datasets: - 3“ (land only) - 30“ (with bathymetry) Available at: http://tethys.eaprs.cse.dmu.ac.uk/ACE2/
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Validation of terrestrial data – Heights • Differences to ACE2 • Max.: 915 m • Min.: -1365 m • Mean: 2.8 m • STD: 53.7m
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Validation of terrestrial data – Heights • Differences to ACE2 • Filtered at 80m(~25 mGal Free-Air) • Max.: 80 m • Min.: -80 m • Mean: 0.4 m • STD: 25,1 m
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Datasources - Satellite gravity data The satellite only model GOCO03s GRACE: 7.5 years GOCE: 18 months SLR: 5 years, 5 sat CHAMP: 8 years Constrains: Kaula, deg > 180 Available at: http://www.goco.eu/ (Mayer-Gürr et.al: The new combined satellite only model GOCO03s, 2012)
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 [mgal] GOCO03S EGM2008 Max. Diff 216.66 102.59 Min. Diff -325.72 -303.86 Mean -6.64 -1.45 RMS 24.08 10.94 Validation of terrestrial data - Gravity Difference terrestrial – GOCO03S (d/o 250) Difference terrestrial – EGM2008 (d/o 2190)
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Calculation schema
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Calculation schema
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Calculation schema
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Preprocessingterrestrialdata • Dimension of normal equationdepends on numberofobservations → restrictionofpoints • Distribution ofpointsisveryinhomogeneous • Calculatedforeachofthe 53.000 stations in studyarea • Selected thestationswiththesmallestvalue q within a radiusof 3 km ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Least Squares Collocation (LSC) … signalcovariances, derivedfromcovariancemodelfittedconsistentlyto (reduced) gravitygradientsand (reduced) terr. data … noisecovariances: - terrestrialdata: empirical- satellitegravitydata: covariancepropagation (includingomissionerror !!!) BIG advantage: weobtainerrorestimates:
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Input data & stochastic models mGal 60 40 20 0 -20 -40 -60 • Satellitedata (reduced): • Synthetizedfrom GOCO03S, on grid • Error information: • - commissionpart: derivedbyfullcovariancepropa-gationfrom GOCO03S variance-covariancematrix • - omissionpart (> d/o 250) : derivedbyvariancepropagationfrom EGM2008 variances mGal 60 40 20 0 -20 -40 -60 • Terrestrial & altimetrydata: • Terrestrialdata: 9910 points, irregularlydistributed • Altimetrydata (DTU10): 2353 points, on grid • Error information: accordingtoqualitycriterion, ~10 mGal (land), ~4-5 mGal (ocean)
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Results Output field [mGal] Error estimates [mGal] • Larger errors where only satellite data available (mainly omission part!!!) • Realistic error estimates.
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Restore & Validation with EGM2008 Restore (GOCO d/o 100 + topo-iso) IMOSAGA01C Free-air anomalies Bouguer anomalies IMOSAGA01C EGM2008 IMOSAGA01C EGM2008 difference mGal
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Restore & Validation with EGM2008 Restore (GOCO d/o 100 + topo-iso) IMOSAGA01C Error estimates [mGal] terrestr. input difference • Improved long-wavelength behaviour • Large differences in regions without terrestrial gravity • Geophysical interpretation (Kiel) IMOSAGA01C makes more sense mGal
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Lithospheric model (IGMAS+) - Iquique • Iquique: terrestrial gravity available Free-air anomalies Bouguer anomalies IMOSAGA01C EGM2008 IMOSAGA01C EGM2008 difference mGal
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Lithosphericmodel (IGMAS+) - Iquique • Only small variations compared to EGM2008 • Lithospheric model could be confirmed
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Lithospheric model (IGMAS+) - Beule • Beule: low-quality terrestrial gravity data Free-air anomalies Bouguer anomalies IMOSAGA01C EGM2008 IMOSAGA01C EGM2008 difference mGal
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Lithosphericmodel (IGMAS+) - Beule • Significant deviationto EGM2008 • Updated lithosphericmodelrequired (currentlydone)
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Lithospheric modelling • In many regions due to lack of terrestrial gravity data up to now no lithospheric profile could be modelled by IGMAS+. • In these regions, now due to GOCE data lithospheric modelling will become possible for the first time!
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Summary and conclusions • Significant improvementof regionalgravityfieldmodelsthroughcombinationofterrestrialandsatellitedata • Main benefitin areaswithterrestrialdatagaps, but also concerningtheconsistency in thelongtomedium wavelengths • Proofof a clearimpactof GOCE forlithosphericmodelling, especially in topographicallychallangingregions • Methodology also usableforvalidationofinhomogenousgravitydatabases • Establishedprocessingprocedurecanbeappliedworldwide (also withlow-quality terrestrialdata) • Updated lithosphericmodels will beavailablesoon
ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013 Final conclusion GOCE rocks … ESA Living Planet Symposium 2013,Edinburgh, September 09-13 2013