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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-24 11:31 |
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Conference: Bucharest University Faculty of Physics 2021 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Vertical deformations in the Carpathian-Danubian-Pontic area
Authors:
Eduard NASTASE (1), Alexandra MUNTEAN (1), Sorin NISTOR (2), Suba NORBERT-SZABOLCS (2)
*
Affiliation:
(1) National Institute for Earth Physics, Magurele, Romania
(2) University of Oradea, Department of Cadastre-Architecture, Oradea, Romania
E-mail
eduard_nastase@infp.ro
Keywords:
Global Positioning System (GPS); Precise Point Positioning (PPP); Maximum Likelihood Estimation (MLE); vertical land motion; Geodesy; Median Interannual Difference Adjusted for Skewness (MIDAS); GPS Imaging;
Abstract:
We describe a comprehensive analysis of permanent Romanian Global Navigation Satellite System (GNSS) sites’ on vertical position time series from data spanning 3-20 years. The GPS observations were computed using Gipsy X software, we apply Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface (Hammond et al.,2016), and the final estimates to obtain the stations’ vertical deformations velocities were analyzed using Maximum Likelihood Estimation (MLE) and Median Interannual Difference Adjusted for Skewness (MIDAS) trend estimator which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity (Blewitt et al.,2016). We focus on the known national GPS observation level model in the Carpathian-Danubian-Pontic area to advance geodetic observation precision/accuracy toward 0.1 mm/year and therefore further constrain models of GIA and subsequent present-day ice mass change estimates at 45 degrees latitudes. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust, and edges in the field remain sharp. Our investigation results will be applied to the revised analysis strategies of vertical deformations over the Romanian region.
References:
Blewitt, G., C. Kreemer, W. C. Hammond,and J. Gazeaux (2016), MIDAS robusttrend estimator for accurate GPS stationvelocities without step detection,J. Geophys. Res. Solid Earth, 121,2054–2068, doi:10.1002/2015JB012552
Hammond, W. C., G. Blewitt, andC. Kreemer (2016), GPS Imaging ofvertical land motion in California andNevada: Implications for Sierra Nevadauplift, J. Geophys. Res. Solid Earth, 121,7681–7703, doi:10.1002/2016JB013458.
Acknowledgement:
This paper was carried out within project SETTING Integrated thematic services in the field of Earth observation - a national platform for innovation, cofunded from the Regional Development European Fund (FEDR) through the Operational Competitivity Programme 2014-2020, Contract No. 336/390012 and NUCLEU Program MULTIRISC, supported
by MCI, project no PN19080201
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