headerpos: 9353
 
 
  Estonian Journal of Earth Sciences

ISSN 1736-7557 (electronic)  ISSN 1736-4728 (print)
An international scientific journal

Formerly: Proceedings of the Estonian Academy of Sciences, Geology
Published since 1952

Estonian Journal of Earth Sciences

ISSN 1736-7557 (electronic)  ISSN 1736-4728 (print)
An international scientific journal

Formerly: Proceedings of the Estonian Academy of Sciences, Geology
Published since 1952

Publisher
Journal Information
» Editorial Board
» Editorial Policy
» Article Publication Charges
» Archival Policy
» Copyright and Licensing Policy
Guidelines for Authors
» Instructions to Authors
Guidelines for Reviewers
» Review Form
Open Access
List of Issues
» 2019
Vol. 68, Issue 3
Vol. 68, Issue 2
Vol. 68, Issue 1
» 2018
» 2017
» 2016
» 2015
» 2014
» 2013
» 2012
» 2011
» 2010
» 2009
» 2008
» 2007
» Back issues (full texts)
  in Google
» Back issues (full texts)
  in Google Ecology
» Back issues in ETERA
Keemia. Geoloogia
» ETERA_scan
Subscription Information
Internet Links
Support & Contact
Publisher
» Other Journals
» Staff

Gravity anomaly field over Estonia; pp. 55–75

(Full article in PDF format) https://doi.org/10.3176/earth.2019.06


Authors

Tõnis Oja, Artu Ellmann, Silja Märdla

Abstract

Different gravity reference frames, methods and instruments have been used by several institutions for conducting gravimetric measurements in Estonia within the past 70 years. Accordingly, a careful evaluation of the obtained gravity data is required before their use in applied science and scientific research. The focus of this study is on (i) the determination and elimination of discrepancies between different gravity datasets and (ii) the prediction of a high-quality gravity anomaly grid for the Estonian territory and adjacent areas.
About 144 000 gravity points were evaluated with outlier detection and removal. Some high-resolution data sets were also low-pass filtered to meet the requirements of geodetic applications like the determination of regional and national geoid models. Remaining 31 850 high-quality data points (22% of initial data) with additional metadata were used in the compilation of the Estonian Gravity Database (EGDB). Recent international cooperation (NKG2015 geoid and FAMOS marine survey projects) resulted in additional 17 339 points in the neighbouring countries and marine areas. These were used as auxiliary data to the EGDB in the computation of gravity anomaly grids.
The conversion of gravity data to the residual terrain model anomaly (RTMA) values is a novel approach to improve the prediction accuracy of the regional gravity anomaly grids in Estonia. The resulting RTMA model obtained for the Estonian territory from the least-squares collocation prediction indicates high accuracy (low uncertainty) according to the statistical estimates and geostatistical analysis. As examples, some gravity field-related products were derived from the RTMA model for possible application in geosciences and other fields
.

Keywords

gravity reference frame, gravimetric database, gravity anomaly, residual terrain model anomaly, stochastic spatial prediction, least-squares collocation.

References

Ågren , J. , Strykowski , G. , Bilker-Koivula , M. , Omang , O. , Märdla , S. , Forsberg , R. , Ellmann , A. , Oja , T. , Liepinš , I. , Paršeliunas , E. , Kaminskis , J. , Sjöberg , L. & Valsson , G. 2016. The NKG2015 gravimetric geoid model for the Nordic-Baltic region. Presented at the 1st Joint Commission 2 and IGFS Meeting International Symposium on Gravity , Geoid and Height Systems. Thessaloniki , Greece.

All , T. & Gromov , O. 2005. Geoloogilise baaskaardi Vaida (6341) lehe gravimeetrilise teemakihi täiendamine [Complementing the gravimetric layer of the geological base-map Vaida (6341) sheet]. Technical report , Eesti Geoloogiakeskus , EGF , 20 pp. [in Estonian].

All , T. , Puura , V. & Vaher , R. 2004. Orogenic structures of the Precambrian basement of Estonia as revealed from the integrated modelling of the crust. Proceedings of the Estonian Academy of Sciences , Geology , 53 , 165–189.

Andersen , O. B. 2013. Marine gravity and geoid from satellite altimetry. In Geoid Determination (Sansò , F. & Sideris , M. G. , eds) , Lecture Notes in Earth System Sciences , 110 , 401–451.
https://doi.org/10.1007/978-3-540-74700-0_9

Birgiel , E. , Ellmann , A. & Delpeche-Ellmann , N. 2018. Examining the performance of the Sentinel-3 coastal altimetry in the Baltic Sea using a regional high-resolution geoid model. In 2018 Baltic Geodetic Congress (BGC Geomatics) , Olsztyn , Poland , 2123 June , 2018 , pp. 196–201. IEEE Computer Cociety.
https://doi.org/10.1109/BGC-Geomatics.2018.00043

Boedecker , G. 1988. International Absolute Gravity Basestation Network (IAGBN). Absolute gravity observations data processing standards and station documentation. Bureau Gravimétrique International (BGI) , Bulletin d'Information , 63 , 51–57.

Bruinsma , S. L. , Förste , C. , Abrikosov , O. , Marty , J.‐C. , Rio , M.‐H. , Mulet , S. & Bonvalot , S. 2013. The new ESA satellite‐only gravity field model via the direct approach. Geophysical Research Letters , 40 , 3607–3612.
https://doi.org/10.1002/grl.50716

Cressie , N. 1993. Statistics for Spatial Data. John Wiley & Sons , New York , 900 pp.
https://doi.org/10.1002/9781119115151

Denker , H. 2015. A new European gravimetric (quasi)geoid EGG2015. Poster presented at XXVI General Assembly of the International Union of Geodesy and Geophysics (IUGG) , 22 June–02 July 2015 , Prague , Czech Republic , www.isgeoid.polimi.it/Geoid/Europe/IUGG_2015_EGG2015.pdf [accessed 20/03/2019].

Denker , H. , Barriot , J.-P. , Fairhead , R. , Forsberg , D. , Ihde , J. , Kenyeres , A. , Marti , U. , Sarrailh , M. & Tziavos , I. N. 2009. The development of the European Gravimetric Geoid model EGG07. In Observing Our Changing Earth , IAG Symposia Series Vol. 133 (Sideris , M. , ed.) , pp. 177–186. Springer , Berlin.
https://doi.org/10.1007/978-3-540-85426-5_21

Dermanis , A. 1984. Kriging and collocation – a comparison. Manuscripta Geodetica , 9 , 159–167.

Dmitrijeva , M. , Plado , J. & Oja , T. 2018. The Luusika potential field anomaly , eastern Estonia: modelling results. Estonian Journal of Earth Sciences , 67 , 228–237.
https://doi.org/10.3176/earth.2018.18

Ellmann , A. 1999. Eesti kõrgtäpse nivelleerimisvõrgu mõõtmis­tulemuste andmetöötlus ja tasandamine [Data processing and adjustment of the Estonian high-precision levelling network]. Geodeet , 20 , 6–8 [in Estonian , with English abstract].

Ellmann , A. 2001. Least Squares Modification of Stokes Formula with Applications to the Estonian Geoid. Division of Geodesy , Royal Institute of Technology , Report No. 1056 , Stockholm , viii+98 pp.

Ellmann , A. 2002. An improved gravity anomaly grid and a geoid model for Estonia. Proceedings of the Estonian Academy of Sciences , Geology , 51 , 199−214.

Ellmann , A. 2005. Two deterministic and three stochastic modifications of Stokes’s formula: a case study for the Baltic countries. Journal of Geodesy , 79 , 11–23.
https://doi.org/10.1007/s00190-005-0438-1

Ellmann , A. , All , T. & Oja , T. 2009. Towards unification of terrestrial gravity data sets in Estonia. Estonian Journal of Earth Sciences , 58 , 229–245.
https://doi.org/10.3176/earth.2009.4.02

Ellmann , A. , Oja , T. & Jürgenson , H. 2011. Kosmosetehno­loogia rakendused geoidi ja gravitatsioonivälja täpsusta­miseks Eesti alal [Application of space technologies to improve geoid and gravity field models over Estonia]. Geodeet , 41 , 22–25 [in Estonian].

Ellmann , A. , Väling , P. & Oja , T. 2016. Meregravimeetrilised mõõdistused Lääne-Eesti vetes FAMOS projekti raames [Marine gravimetric surveys in the West-Estonian waters under the FAMOS project]. Geodeet , 45/46 , 80−82 [in Estonian].

Ellmann , A. , Märdla , S. & Oja , T. 2019. The 5 mm geoid model for Estonia computed by the least squares modified Stokes formula. Survey Review , DOI: 10.1080/00396265.2019.1583848.
https://doi.org/10.1080/00396265.2019.1583848

[EME] Estonian Ministry of Environment. 2017. Geodeetiline Süsteem [Geodetic system]. In Legal Acts of Estonia , Decree No. 64 , Riigi Teataja I , https://www.riigiteataja.ee/ akt/128102011003?leiaKehtiv [in Estonian , accessed 26/11/2018].

[FAMOS] FAMOS Consortium. 2014. The FAMOS Project. Available at http://www.famosproject.eu/famos [accessed 09/11/2018].

Farahani , H. H. , Klees , R. & Slobbe , C. 2017. Data require­ments for a 5-mm quasi-geoid in the Netherlands. Studia Geophysica et Geodaetica , 61 , 675–702.
https://doi.org/10.1007/s11200-016-0171-7

Farr , T. G. , Rosen , P. A. , Caro , E. , Crippen , R. , Duren , R. , Hensley , S. , Kobrick , M. , Paller , M. , Rodriguez , E. , Roth , L. , Seal , D. , Shaffer , S. , Shimada , J. , Umland , J. , Werner , M. , Oskin , M. , Burbank , D. & Alsdorf , D. 2007. The Shuttle Radar Topography Mission. Reviews of Geophysics , 45 , RG2004.
https://doi.org/10.1029/2005RG000183

Fecher , T. , Pail , R. , Gruber , T. & the GOCO Consortium. 2017. GOCO05c: A new combined gravity field model based on full normal equations and regionally varying weighting. Surveys in Geophysics , 38 , 571–590.
https://doi.org/10.1007/s10712-016-9406-y

[FGI] Finnish Geodetic Institute. 2003. Certificate of Calibration No. 6/2003. Finnish Geodetic Institute , National Standards Laboratory.

Forsberg , R. 1984. A Study of Terrain Reductions , Density Anomalies and Geophysical Inversion Methods in Gravity Field Modelling. The Ohio State University , Report No. OSU/DGSS-355 , 129 pp.
https://doi.org/10.21236/ADA150788

Forsberg , R. & Tscherning , C. C. 2008. Geodetic Gravity Field Modelling Programs. An Overview Manual for the GRAVSOFT. Second Edition , 77 pp.

Forsberg , R. , Kaminskis , J. & Solheim , D. 1997. Geoid for the Nordic and Baltic region from gravimetry and satellite altimetry. In Gravity , Geoid and Marine Geodesy (Segawa , J. , Fujimoto , H. & Okubo , S. , eds) , International Association of Geodesy Symposia , 117 , 540–547.
https://doi.org/10.1007/978-3-662-03482-8_72

Forsberg , R. , Olesen , A. V. , Keller , K. , Møller , M. , Gidskehaug , A. & Solheim , D. 2001. Airborne gravity and geoid surveys in the Arctic and Baltic Seas. In Proceedings of the International Symposium on Kinematic Systems in Geodesy , Geomatics and Navigation (KIS-2001) , Banff 2001 , pp. 586–593.

Forsberg , R. , Strykowski , G. & Solheim , D. 2004. NKG2004 geoid of the Nordic and Baltic area. In Proceedings on CD-ROM from the IAG , Gravity , Geoid and Satellite Gravity Missions , August 30–September 3 , Porto , Portugal.

Gromov , O. & Gromova , G. 1968. Otchet o gravimetricheskoj s″emke masshtaba 1 : 25 000 na territorii Tsentral′noj Éstonii za 1965–1967 gody [Gravity mapping at a scale of 1 : 25 000 in the central part of Estonia , 1965–1967]. Tallinn , EGF 2994 , Technical report , 128 pp. [in Russian].

Gruno , A. , Liibusk , A. , Ellmann , A. , Oja , T. , Vain , A. & Jürgenson , H. 2013. Determining sea surface heights using small footprint airborne laser scanning. In Remote Sensing of the Ocean , Sea Ice , Coastal Waters , and Large Water Regions 2013 (Bostater , C. , Mertikas , S. , Neyt , X. & Bruyant , Y.-P. , eds) , pp. 88880R-1–88880R-13. Dresden.
https://doi.org/10.1117/12.2029189

Heiskanen , W. A. & Moritz , H. 1967. Physical Geodesy. W. H. Freeman & Co. , San Francisco , 374 pp.

Jekeli , C. 2012. Omission error , data requirements , and the fractal dimension of the geoid. In VII Hotine-Marussi Symposium on Mathematical Geodesy (Sneeuw , N. , Novák , P. , Crespi , M. & Sansò , F. , eds) , International Association of Geodesy Symposia , 137 , 181–187.
https://doi.org/10.1007/978-3-642-22078-4_27

Jürgenson , H. 1998. Gravimeetrilise põhivõrgu mõõtmised 1998. a. suvel ja geoidi pinna arvutus [Gravimetrical measurements in 1998 and new determination of the geoid surface]. Geodeet , 17 , 8−15 [in Estonian].

Jürgenson , H. 2001. Geoid computations in Estonia. IGeS Bulletin , 11 , 21–29.

Jürgenson , H. 2003. Eesti täppisgeoidi arvutus [Determination of Estonian precision geoid]. Thesis (PhD) , Estonian University of Life Sciences , Tartu , Estonia , 157 pp. [in Estonian , with English summary].

Kall , T. , Oja , T. & Tänavsuu , K. 2014. Postglacial land uplift in Estonia based on four precise levelings. Tectonophysics , 610 , 25–38.
https://doi.org/10.1016/j.tecto.2013.10.002

Karell , F. , Ehlers , C. & Airo , M.-L. 2014. Emplacement and magnetic fabrics of rapakivi granite intrusions within Wiborg and Åland rapakivi granite batholiths in Finland. Tectonophysics , 614 , 31–43.
https://doi.org/10.1016/j.tecto.2013.12.006

Kasper , J. F. Jr. 1971. A second-order Markov Gravity Anomaly Model. Journal of Geophysical Research , 76 , 7844–7849.
https://doi.org/10.1029/JB076i032p07844

Korhonen , J. , Koistinen , T. , Elo , S. , Säävuori , H. , Kääriäinen , J. , Nevanlinna , H. , Aaro , S. , Haller , L. Å. , Skilbrei , J. R. , Solheim , D. , Chepik , A. K. , Zhdanova , L. , Vaher , R. , All , T. & Sildvee , H. 1999. Preliminary magnetic and gravity anomaly maps of the Fennoscandian shield 1 : 10 000 000. Geological Survey of Finland Special Paper , 27 , 173–179.

Lemoine , F. G. , Kenyon , S. C. , Factor , J. K. , Trimmer , R. G. , Pavlis , N. K. , Chinn , D. S. , Cox , C. M. , Klosko , S. M. , Luthcke , S. B. , Torrence , M. H. , Wang , Y. M. , Williamson , R. G. , Pavlis , E. C. , Rapp , R. H. & Olson , T. R. 1998. The Development of the Joint NASA GSFC and the National Imagery and Mapping Agency (NIMA) Geopotential Model EGM96. Greenbelt , Md.: National Aeronautics and Space Administration , Goddard Space Flight Center , NASA/TP-1998-206861 , 584 pp.

Maasik , V. 1950. Eesti NSV maa-alal 1949. aastal teostatud gravimeetrilised mõõdistamise tulemused [Gravimetric survey results done in the Estonian SSR territory in 1949]. ENSV TA Geoloogia Instituut , Tallinn , 97 pp. [in Estonian].

Maasik , V. 1952. Gravimeetrilised loejoone kõrvalekalded ja geoidi pind Eesti NSV keskosas [Gravimetric plumb line deflections and geoid surface in the middle of Estonian SSR]. ENSV TA Geoloogia Instituut , Tallinn , 32 pp. [in Estonian].

Maasik , V. 1958. Gravimetricheskie issledovaniya territorii Éstonskoj SSR (Opredelenie mestnykh iskhodnykh gravimetricheskikh punktov 1957 g) [Gravimetric studies on the territory of the Estonian SSR (Establishment of the local gravity reference points in 1957)]. Institut Geologii AN ESSR , Tallinn , 103 pp. [in Russian].

Maasik , V. 1959. Gravitatsionnoe pole na territorii Éstonskoj SSR i ego primenenie. Opredelenie sily tjazhesti i poluchennye rezulʹtaty [Gravitational field in the territory of the Estonian SSR and its application. Determination of gravity and the received results]. Institut Geologii AN ESSR , Part 1 , Tallinn , 156 pp. [in Russian].

Mäkinen , J. , Bilker-Koivula , M. , Falk , R. , Gitlein , O. , Kaminskis , J. , Lapushka , K. , Oja , T. , Paršeliunas , E. , Petroškevičius , P. & Timmen , L. 2009. Gravity change from repeated absolute measurements in Estonia , Latvia and Lithuania 1994–2008. Geophysical Research Abstracts , 11 , EGU2009-13286-1. EGU General Assembly 2009 , Vienna , Austria.

Märdla , S. 2017. Regional Geoid Modelling by Least Squares Modified Hotine Formula. Doctoral thesis , Tallinn University of Technology , 210 pp.

Märdla , S. , Ellmann , A. , Oja , T. & Jürgenson , H. 2016. Improving and validating gravity data over ice-covered marine areas. International Association of Geodesy Symposia , 143 , 263–270.
https://doi.org/10.1007/1345_2015_163

Märdla , S. , Ågren , J. , Strykowski , G. , Oja , T. , Ellmann , A. , Forsberg , R. , Bilker-Koivula , M. , Omang , O. , Paršeliunas , E. , Liepinš , I. & Kaminskis , J. 2017. From discrete gravity survey data to a high-resolution gravity field represen­tation in the Nordic–Baltic Region. Marine Geodesy , 40 , 416–453.
https://doi.org/10.1080/01490419.2017.1326428

Märdla , S. , Ellmann , A. , Ågren , J. & Sjöberg , L. 2018. Regional geoid computation by least squares modified Hotine’s formula with additive corrections. Journal of Geodesy , 92 , 253–270.
https://doi.org/10.1007/s00190-017-1061-7

Marson , I. , Faller , J. E. , Cerutti , G. , De Maria , P. , Chartier , J.-M. , Robertsson , L. , Vitushkin , L. , Friederich , J. , Krauterbluth , K. , Stizza , D. , Liard , J. , Gagnon , C. , Lothhammer , A. , Mäkinen , J. , Murakami , M. , Rehren , F. , Schnüll , M. , Ruess , D. & Sasagawa , G. S. 1995. Fourth international comparison of absolute gravimeters. Metrologia , 32 , 137–144.
https://doi.org/10.1088/0026-1394/32/3/001

Morelli. C. , Gantar , C. , Honkasalo , T. , McConnell , R. K. , Tanner , I. G. , Szabo , B. , Uotila , L. J. & Whalen , C. T. 1971. The International Gravity Standardization Network (IGSN71). Bulletin Géodésique , Special Publication , 4 , 1–194.

Moritz , H. 1980. Advanced Physical Geodesy. Herbert Wichmann Verlag , Karlsruhe , Abacus Press , Tunbridge Wells , Kent , 500 pp.

Oja , T. 2007. Gravimeetrilised süsteemid ja võrgud Eestis: IGNS71 ja EGS ajavahemikus 1975–2007 [Gravity systems and networks in Estonia: IGSN71 and EGS from 1975 to 2007]. Geodeet , 35 , 11–20 [in Estonian].

Oja , T. 2008. New solution for the Estonian gravity network GV-EST95. In The 7th International Conference , Environ­mental Engineering Selected Papers , 3 , 1409–1414.

Oja , T. , 2012. Gravity system and network in Estonia. In Geodesy for Planet Earth (Kenyon , S. , Pacino , M. & Marti , U. , eds) , International Association of Geodesy Symposia , 136 , 315–322.
https://doi.org/10.1007/978-3-642-20338-1_38

Oja , T. 2014. Compilation of Estonian Digital Elevation Model EstDEM2013. Unpublished technical report (ver. 2014-10-08) , Estonian Land Board , Tallinn , 10 pp.

Oja , T. 2016. Unstable calibration factor of CG-5 relative gravimeter. Presented at the 1st Joint Commission 2 and IGFS Meeting International Symposium on Gravity , Geoid and Height Systems. Thessaloniki , Greece , www.researchgate.net/publication/316739992_Unstable_calibration_factor_of_CG-5_relative_gravimeter [accessed 20/03/2019].

Oja , T. 2018. EST-GEOID2017 sisendandmete ettevalmistus ja GRAV-GEOID2017 sobitamine GNSS/nivelleerimise andmetega [Preparation of EST-GEOID2017 input data and GRAV-GEOID2017 fitting with GNSS-levelling points]. Unpublished technical report , Estonian Land Board , Tallinn , 59 pp.

Oja , T. , Timmen , L. & Gitlein , O. 2009. 2007. a raskus­kiirenduse mõõtmised Suurupi ja Tõravere punktidel absoluutgravimeetriga FG5-220 [Determination of the gravity acceleration at the Estonian stations Suurupi and Tõravere with the absolute gravimeter FG5-220 in 2007]. Geodeet , 38/39 , 16–27 [in Estonian , with English abstract].

Oja , T. , Türk , K. , Ellmann , A. , Gruno , A. , Bloom , A. & Sulaoja , M. 2011. Relative gravity surveys on ice-covered water bodies. In Selected Papers of the 8th International Conference on Environmental Engineering , pp. 1394–1401. Vilnius Gediminas Technical University Press “Technika”.

Oja , T. , Bilker-Koivula , M. & Mäkinen , J. 2017. Raskus­kiirenduse mõõtmised gravimeetrilise võrgu I klassi punktidel 2017. a. suvel [Absolute gravity measurements on the I order points of the Estonian gravity network in summer 2017]. Geodeet , 47 , 35–38 [in Estonian , with English abstract].

Olesen , A. V. 2017. Marine Gravity Onboard MS Sectori July 2017. Processing report , DTU Space , 7 pp.

Olesen , A. V. & Kasenda , F. 2016. Marine Gravity Onboard Jakob Prey June/July 2016. Processing report , DTU Space , 6 pp.

Olsson , P.-A. , Breili , K. , Ophaug , V. , Steffen , H. , Bilker-Koivula , M. , Nielsen , E. , Oja , T. & Timmen , L. 2019. Postglacial gravity change in Fennoscandia – three decades of repeated absolute gravity observations. Geophysical Journal International , 217 , 1141–1156.
https://doi.org/10.1093/gji/ggz054

Pavlis , N. K. , Holmes , S. A. , Kenyon , S. K. & Factor , J. K. 2012. The development and evaluation of the Earth Gravitational Model 2008 (EGM2008). Journal of Geophysical Research , 117 , B04406.
https://doi.org/10.1029/2011JB008916

Puura , V. & Flodén , T. 1999. Rapakivi-granite–anorthosite magmatism – a way of thinning and stabilisation of the Svecofennian crust , Baltic Sea Basin. Tectonophysics , 305 , 75–92.
https://doi.org/10.1016/S0040-1951(99)00019-0

Robertsson , L. , Francis , O. , van Dam , T. M. , Faller , J. , Ruess , D. , Delinte , J.-M. , Vitushkin , L. , Liard , L. , Gagnon , C. , Guo You Guang , Huang Da Lun , Fang Yong Yuan , Xu Jin Yi , Jeffries , G. , Hopewell , H. , Edge , R. , Robinson , I. , Kibble , B. , Mäkinen , J. , Hinderer , J. , Amalvict , M. , Luck , B. , Wilmes , H. , Rehren , F. , Schmidt , K. , Schnüll , M. , Cerutti , G. , Germak , A. , Zabek , Z. , Pachuta , A. , Arnautov , G. , Kalish , E. , Stus , Y. , Stizza , D. , Friederich , J. , Chartier , J.-M. & Marson , I. 2001. Results from the Fifth International Comparison of Absolute Gravimeters , ICAG97. Metrologia , 38 , 71–78.
https://doi.org/10.1088/0026-1394/38/1/6

Rüdja , A. 2016. Kõrgusvõrgu rekonstrueerimine. Tasandus­arvutused [Reconstruction of Height Network. Adjustment Computations]. Unpublished geodetic report , part I , AS Planserk , Tallinn , 103 pp. [in Estonian].

Sildvee , H. 1998. Gravity measurements of Estonia. Reports of the Finnish Geodetic Institute , 98:3 , 1–8.

Sildvee , H. & Oja , T. 1999. Eesti gravimeetriline põhivõrk [Estonian gravity base network]. Geodeet , 21 , 10–13 [in Estonian].

Sildvee , H. & Vaher , R. 1995. Geologic structure and seismicity of Estonia. Proceedings of the Estonian Academy of Sciences , Geology , 44 , 15–25.

Talvik , S. & Oja , T. 2014. Eesti gravimeetriline andmebaas [The Estonian Gravity Database]. Unpublished report , Tallinn University of Technology , Estonian Land Board , 27 pp. [in Estonian].

Türk , K. , Sulaoja , M. , Oja , T. , Ellmann , A. & Jürgenson , H. 2011. Precise gravity surveys in South-Estonia from 2009 to 2010. In Selected Papers of the 8th Inter­national Conference on Environmental Engineering (Cygas , D. & Froehner , K. D. , eds) , pp. 1499–1505. Vilnius , Lithuania.

Varbla , S. , Ellmann , A. , Märdla , S. & Gruno , A. 2017. Assessment of marine geoid models by ship-borne GNSS profiles. Geodesy and Cartography , 43 , 41–49.
https://doi.org/10.3846/20296991.2017.1330771

Vermeer , M. 1994. A fast delivery GPS-gravimetric geoid for Estonia. Reports of the Finnish Geodetic Institute , 94:1 , 1–7.

Wessel , P. , Smith , W. H. F. , Scharroo , R. , Luis , J. F. & Wobbe , F. 2013. Generic mapping tools: Improved version released. EOS , Transactions of the American Geophysical Union , 94 , 409–410.
https://doi.org/10.1002/2013EO450001

 
Back

Current Issue: Vol. 68, Issue 3, 2019




Publishing schedule:

No. 1: 20 March
No. 2: 20 June
No. 3: 20 September
No. 4: 20 December