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Titre : Improvement of the kinematic model of Switzerland (Swiss 4D 2) Type de document : Thèse/HDR Auteurs : Arturo Villiger, Auteur Editeur : Zurich : Schweizerischen Geodatischen Kommission / Commission Géodésique Suisse Année de publication : 2014 Collection : Geodätisch-Geophysikalische Arbeiten in der Schweiz, ISSN 0257-1722 num. 90 Importance : 130 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-908440-36-9 Note générale : Bibliographie
Doctoral ThesisLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] collocation par moindres carrés
[Termes IGN] déformation de la croute terrestre
[Termes IGN] positionnement par GNSS
[Termes IGN] réseau géodésique local
[Termes IGN] Suisse
[Termes IGN] tectonique des plaques
[Termes IGN] tensionIndex. décimale : 30.82 Applications géophysiques de géodésie spatiale Résumé : (Auteur) Switzerland is a region with relatively low seismicity compared to other lithospheric subduction zones. However, from historic earthquakes it is known that events with large magnitudes, above 6, have occurred. A major task was to extract the tectonic pattern of the velocity field based on Global navigation Satellite Systems (GNSS) campaign type data (CHTRF 2010 solution) given the fact that the noise level and local influences are within the same order of magnitude as the deformation occurring.
The introduction of the adaptive least-squares collocation (ALSC) and its enhancement to determine the tectonically driven deformation field allowed to extract a reliable kinematic model for Switzerland. The final solution consists of the velocity field and its derivative, the strain rate field. Due to the relatively high density of measurement points, re-measured three or more times, the field could be retrieved from the data set. The horizontal velocities are mostly below 1 mm/yr and the uplift rates, determined from precise levelling, between 0 and 1.5 mm/yr. The deformation rates deduced amount to 25 nstrain/yr.
The thin plate model allowed to estimate also the vertical strain rate which was not possible to retrieve by the collocation technique alone. This is due to the lack of missing measurements within the crust since all levelling and GNSS measurements are performed on the surface. The comparison of the strain rate field with seismological data showed a good accordance. The horizontal strain field confirms a compression of 15 nstrain/yr perpendicular to the Alpine chain. In the canton Valais seismic recordings observed extensional stress regimes. The collocation technique could reproduce the extension and retrieved a strain rate of 20 nstrain/yr. At the boundary of the study area uncertainties exists because of missing data outside Switzerland. This is a particular problem in the city of Basel, which lies at the southern end of the Upper Rheingraben. The 3-D strain rate tensor, using the thin plate model, has shown mostly similar fault plane solutions as the one obtained from earthquake analysis. The same is valid for the strain rate energy compared with the seismic energy released by earthquakes. The highest strain energy density is found in the eastern and western part of the Swiss Alps.
This project has been funded by swisstopo and the Geodesy and Geodynamics Lab, ETH Zurich. The work which was carried out for the project COGEAR was financed by the Competence Center Environment and Sustainability of the ETH Domain (CCES).Note de contenu : 1 Introduction
1.1 Scope of work
1.2 Research tasks
1.3 Tectonic setting
1.4 Geodetic strain determination in Switzerland
2 Data and data analysis
2.1 Data sources
2.2 Regional effects
2.3 Local effects
2.4 Multipath
2.5 Uplift rates from GNSS and levelling
3 Block detection
3.1 Automatic block detection using a genetic algorithm
3.2 Manual block definition based on geological information
3.3 Conclusion
4 Adaptive least-squares collocation: Theory
4.1 Theory
4.2 Dilatation
4.3 Parameter estimation
4.4 Thin plate model
4.5 Strain energy density
4.6 Fault planes from strain
5 Adaptive least-squares collocation: Results
5.1 Generic example
5.2 CHTRF 2010
6 Comparison of the strain rate field with geophysical findings
6.1 Kinematic Model of Switzerland
6.2 Strain Energy
6.3 Strain rate tensor comparison
6.4 Comparison with seismic findings
6.5 Comparison with world wide models
7 Dense GNSS network for small scale tectonic analysis in the Canton of Valais
7.1 Introduction
7.2 GNSS network
8 Conclusion and outlookNuméro de notice : 15849 Affiliation des auteurs : non IGN Autre URL associée : URL ETH Zurich Thématique : POSITIONNEMENT Nature : Thèse étrangère DOI : 10.3929/ethz-a-010163325 En ligne : http://e-collection.library.ethz.ch/view/eth:8673 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75687 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 15849-01 30.82 Livre Centre de documentation Géodésie Disponible Analysis of long-term GPS observations in Greece (1993-2009) and geodynamic implications for the Eastern Mediterranean / Michael D. Müller (2011)
Titre : Analysis of long-term GPS observations in Greece (1993-2009) and geodynamic implications for the Eastern Mediterranean Type de document : Rapport Auteurs : Michael D. Müller, Auteur Editeur : Zurich : Schweizerischen Geodatischen Kommission / Commission Géodésique Suisse Année de publication : 2011 Collection : Geodätisch-Geophysikalische Arbeiten in der Schweiz, ISSN 0257-1722 num. 82 Importance : 186 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-908440-28-4 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Athènes
[Termes IGN] champ de vitesse
[Termes IGN] collocation par moindres carrés
[Termes IGN] Egée, mer
[Termes IGN] Grèce
[Termes IGN] méthode des éléments finis
[Termes IGN] Péloponnèse
[Termes IGN] séisme
[Termes IGN] vitesseIndex. décimale : 30.82 Applications géophysiques de géodésie spatiale Résumé : (Auteur) The Global Positioning System (GPS) is used to determine rates of crustal motion in the Hellenic plate boundary zone since the late eighties. The zone comprises Greece and its adjacent regions. It is characterized by the interaction of the Eurasian, Anatolian and Nubian plates moving relative to each other. Tectonic processes associated with this motion cause the highest seismic activity of Europe. Nine earthquakes with magnitude six or higher occurred within this region in the period 2006 to 2011. International efforts are being made to achieve a better understanding of the origin and characteristics of ongoing seismotectonic processes. The ETH Zurich has taken active part in these efforts. Results achieved so far provide valuable boundary conditions for geodynamic modeling. In close collaboration with other institutes an extensive GPS network has been established and periodically remeasured. The network consists of campaign-type and continuous GPS sites. The corresponding data record has been significantly extended in the course of the thesis. A 16 year record of GPS data (19932009) is available now for Greece. In its first part the thesis deals with the evaluation of the data record. The strategy of GPS analysis was enhanced compared to proceeding projects by applying recent GPS processing models and improving postprocessing procedures. The concept of including data of numerous IGS and EUREF sites located in Europe, North Africa and the Middle East was continued. This allowed for a precise alignment of the GPS network to a global reference frame (ITRF2005), the reduction of processing induced systematic signals and the determination of a pole of rotation for the Eurasian plate.
An improved kinematic field was derived which was analyzed in terms of slowly deforming regions by using a block model. The modeling provides several insights. For instance, northwestern Greece rotates clockwise (cw) and the region south of the North Aegean trough (NAT) rotates counterclockwise (ccw) relative to Eurasia. Both areas form blocks with small internal deformation. Moreover, they describe the western termination of the North Aegean trough. A large part of ongoing deformation is located in confined regions.
The GPS derived deformation field provides information about ongoing tectonic processes. These include N-S extension between Northern Greece and the Gulf of Corinth and dextral shear strain in the North Aegean sea as well as along the Kefalonia fault zone in the Ionian sea. New results concerning ongoing deformation processes were achieved in the Southeast Aegean sea and in Northern Greece. Pronounced N-S extension (100 nstrain/yr) was determined across the Mygdonian graben. NNW-SSE extension amounting to 150 nstrain/yr was found between the islands of Kalymnos and Tilos in the SE Aegean sea.
The NAT and the Kefalonia fault zone are among the most pronounced transform faults in the Hellenic plate boundary zone. Rates of closely located GPS sites were used for the estimation of the slip rates and locking depths of the structures. Four profiles across the NAT show a decrease of slip rates from the Ganos fault (23 mm/yr) towards the southwestern edge of the Sporades basin (<5 mm/yr). The geodetic results provide further evidence that the NAT forms the westward continuation of the North Anatolian fault zone commencing at the Saros basin. The decrease of slip rates west of the Chalkidiki peninsula is related to a different orientation of the NAT and to NNE-SSW extension in the Sporades basin. Finite element models were used to relate GPS rates to basic geodynamic models. The first model I focused at the analysis of the subduction rate near the central Hellenic trench. The results point to a largely uncoupled interface between the Nubian and Aegean plates. The second model quantifies the slip rates along the three major NE-SW to ENE-WSW trending transform faults in the North Aegean sea. Rates amounting to 21 mm/yr were derived for the NAT, 10 mm/yr for the Skyros- Edremit fault and 4 mm/yr for the Psara-Lesvos fault. Moreover, the model reveals additional deformation zones such as NNE-SSW extension in the Sporades basin. The derived GPS rates and the conducted analyses improve the current understanding of seismotectonic processes in Greece. The investigations also highlight remaining problems and bring forward new ideas which will ultimately be valuable for further analysis and assessment of natural hazard in Greece.Note de contenu : 1 Introduction
1.1 State of research
1.2 Goals
2 Geologic setting
2.1 Evolution of the central and eastern Mediterranean
2.2 Tectonic framework of Greece
3 GPS data evaluation
3.1 Description of relevant GPS networks
3.1.1 Campaign-type GPS network in Greece and southern Bulgaria
3.1.2 Continuous GPS networks in Greece
3.1.3 IGS and EUREF sites
3.2 Strategy of GPS data processing
3.3 Definition of the geodetic datum
3.4 Velocity estimation of CGPS sites
3.4.1 Introduction
3.4.2 Discontinuities in position time series
3.4.3 Removing outliers
3.4.4 Exclusion periods
3.4.5 Estimation of velocities and offsets
3.4.6 Reduction of apparent scale changes of the processed GPS network
3.4.7 Scaling of formal errors of velocities
3.5 Velocity estimation of campaign-type GPS sites
3.6 Factors affecting the velocity estimates
3.6.1 Tracking performance of GPS sites
3.6.2 Used orbits and earth orientation parameters
3.6.3 Campaign-type data of the years 1993 and 1994
3.7 Concluding remarks
4 Kinematic field in Greece (19932009)
4.1 Introduction
4.2 Euler vector and estimation of a pole of rotation for Eurasia (ITRF2005)
4.3 Kinematic block model for Greece
4.4 Kinematic field and modeling in the North Aegean domain
4.4.1 Kinematic field
4.4.2 Slip rates and locking depths along the North Aegean trough
4.5 Kinematics along the Hellenic trench system
4.5.1 Ionian islands, Western Greece and NW Peloponnesos
4.5.2 Southern Peloponnesos and South Aegean sea
4.6 Vertical motion in Greece
4.7 Concluding remarks
5 Strain rates derived by using the method of collocation
5.1 Least-squares collocation
5.2 Velocity and strain rate fields calculation implemented in the program 'strain'
5.3 Strain rates and differential rotations in Greece
5.4 Concluding remarks
6 Seismic signals in GPS time series
6.1 Introduction
6.2 Estimation of earthquake displacements
6.3 Analytical surface dislocation model
6.4 Earthquakes in the Aegean domain
6.4.1 1999 Ms 5.9 Athens earthquake
6.4.2 2001 Mw 6.4 Skyros earthquake
6.4.3 2008 Mw 6.4 Rhodes earthquake
6.5 Earthquakes in the Ionian sea
6.5.1 1997 Mw 6.6 Strofades earthquake
6.5.2 2003 Mw 6.2 Lefkada earthquake
6.5.3 2006 Zakynthos earthquake series
6.5.4 2008 Mw 6.4 NW Peloponnesos earthquake
6.5.5 Comparison of seismicity and interseismic strain rates
6.6 Concluding remarks
7 Finite element models
7.1 Finite element method
7.1.1 Basic theory
7.1.2 Displacement-based finite element analysis
7.2 Physical properties of a model lithosphere
7.2.1 Introductory notes
7.2.2 Elasticity
7.2.3 Brittle failure
7.2.4 Ductile deformation
7.2.5 Temperature in the continental lithosphere
7.3 Interaction between the overriding and the subducting plate at the central Hellenic trench
7.3.1 Geodetic constraints
7.3.2 Developed finite element model
7.4 3D finite element model of the North Aegean sea
7.4.1 Introduction
7.4.2 Model set up
7.4.3 Results
7.5 Concluding remarks
8 ConclusionsNuméro de notice : 14311 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Rapport de recherche En ligne : https://www.sgc.ethz.ch/sgc-volumes/sgk-82.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62654 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 14311-01 30.82 Livre Centre de documentation Géodésie Disponible Present-day crustal dynamics in the Adriatic-Aegean plate boundary zone inferred from continuous GPS-measurements / Yannick Peter (2001)
Titre : Present-day crustal dynamics in the Adriatic-Aegean plate boundary zone inferred from continuous GPS-measurements Type de document : Thèse/HDR Auteurs : Yannick Peter, Auteur Editeur : Zurich : Institut für Geodäsie und Photogrammetrie IGP - ETH Année de publication : 2001 Collection : IGP Mitteilungen, ISSN 0252-9335 num. 71 Importance : 144 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-906467-31-3 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Adriatique, mer
[Termes IGN] collocation
[Termes IGN] coordonnées GPS
[Termes IGN] déformation de la croute terrestre
[Termes IGN] Egée, mer
[Termes IGN] tectonique des plaquesIndex. décimale : 30.82 Applications géophysiques de géodésie spatiale Résumé : (Auteur) The eathquake activity around the Aegean Sea is the most conspicuous geodynamic phenomenon in the Eastern Mediterranean region. The clearest seismicity feature is associated with the Hellenic are forming a semi-circle from the Ionian Islands to Western Anatolia. The right-lateral Kefalonia Fault Zone (KFZ) dominates the seismic activity in the Ionian Sea. Previous GPS measurements have revealed distinct crustal motion of the Central Ionian Islands and SVV Greece in a SW direction relative to SE Italy. The trajectories constructed from repeated observations lead us to interpret the KFZ as part of the boundary zone separating the stable Apulian/Adriatic block from the Aegean/Anatolian region, which is rapidly moving towards the Southwest. In 1995 the progress made in GPS and Computer technology made it, realistic to consider a relative dense continuous GPS (CGPS) network which would bridge the main tectonic units and provide a high temporal resolution of crustal motion. In order to monitor the deformation and evaluate the strain field in the area, we established a network of continuous GPS stations across the KFZ. The first sites were monumented during Spring 1995, and the network was gradually augmented with new stations. It was considered as fully operational by the beginning of 1996. In addition to our own network, data of four surrounding IGS sites (Graz, Matera, Noto and Ankara) were introduced in the processing. The main results are daily Solutions, which can be used to derive time series and rates of crustal motion. A detailed behavior of the different sites during the period 1.995 to 1998 is presented in terms of N-S. E-W and Up components. Clearly non-tectonic discontinuities due to hardware changes were estimated and corrected, increasing the consistency of the Solution. The use ofa common-mode filtering technique reduced the scatter of the time series by a factor of about 2. Following the calculation of the time series, we have determined the rates and trajectories of crustal motion. These data provide a better overview of the kinematic processes across the KFZ. The sites to the north of the KFZ show almost no motion relative to Eurasia, while an increase of rates up to 30±2mm/a is clearly seen when moving to the southern Ionian Islands. The inter-seismic motion of the Aegean block was interrupted by the Strofades earthquake (Ms 6.1, Nov. 18. 1997). which was associated with a distinct south- oriented co-seismic slip of 12 cm and an uplift of about 10 cm. The time series analysis clearly reveals that also the island of Zakinthos was affected by this event (co-seismic slip of 1.5 cm to the south). The deformation rates are evaluated by means of strain analysis, using the collocation method. The resulting strain rates depend strongly on the correlation length chosen. Numéro de notice : 14739 Affiliation des auteurs : non IGN Autre URL associée : http://dx.doi.org/10.3929/ethz-a-004064439 Thématique : POSITIONNEMENT Nature : Thèse étrangère DOI : 10.3929/ethz-a-004064439 En ligne : http://e-collection.library.ethz.ch/eserv/eth:23813/eth-23813-02.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62683 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 14739-01 30.82 Livre Centre de documentation Géodésie Disponible
Titre : Der Mittelmeerraum. Numerische Modellierung der Lithosphärendynamik im Vergleich mit Ergebnissen aus der Satellitengeodäsie Titre original : [L'espace méditerranéen : modélisation numérique de la dynamique de la lithosphère comparée aux données de la géodésie spatiale] Type de document : Thèse/HDR Auteurs : O. Heidbach, Auteur Mention d'édition : 1 Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2000 Collection : DGK - C Sous-collection : Dissertationen num. 525 Importance : 98 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9564-9 Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] bassin méditerranéen
[Termes IGN] champ de vitesse
[Termes IGN] données GPS
[Termes IGN] lithosphère
[Termes IGN] Méditerranée, mer
[Termes IGN] méthode des éléments finis
[Termes IGN] modélisation 3D
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement par télémétrie laser sur satellite
[Termes IGN] tectoniqueIndex. décimale : 30.82 Applications géophysiques de géodésie spatiale Résumé : (Auteur) The collision of the African and Arabian plates with Eurasia results in complex tectonic structures in the Mediterranean region. Broad deformation belts have developed along the border of the plates. Values deviating significantly to those of rigid body motion models are measured with the geodetic satellite methods SLR (Satellite Laser Ranging) and GPS (Global Positioning System).
Aim of the investigation is to create a three-dimensional dynamic model of the Mediterranean. The numerical problem is solved with the finite element method. The resulting velocity field on the surface of the model is compared with the GPS- and SLR-data. This leads to new information about geodynamic processes of the lithosphere. In addition, the question is investigated if this numerical model can be used for a prediction of the surface velocity field and the deformation rate.
The model is built up of various modules. It takes into consideration the radius of the Earth, the variation of topography and Mohorovicic discontinuity and the thickness of the lithosphere. The structure of the subduction- and collision zones will be represented as contact surfaces with Coulomb-friction. Kinematic boundary conditions from the NUVEL-1A rigid body model and the slab pull stress at the Hellenic and Calabrian arc are implemented as further boundary conditions.
The rheology of the upper crust consist of an ideal elastic-plastic body. Its yield strength is computed with the linear Mohr-Coulomb criteria. The lower crust and the lithosphere is assumed to be an ideal visco-elastic body. In the first model series L of the complete Mediterranean region the viscous body is linear, in the second series NL of the Eastern Mediterranean the viscous body is described with non-linear power-law dislocation creeping. By varying the different model parameters their influence on surface deformations is examined.
Finaly it becomes evident that the slab pull stress and the friction coefficient have the strongest effect on surface deformation. With a slab pull stress of 150 MPa and a friction coefficient between 0,2 and 0,35 the model shows the best results. Taking into further consideration the different yield strengths under compression and extension the model leads to a mean deviation of ±24,2% (magnitude) and ±10,8° (azimuth) in comparison with 40 GPS and SLR-stations within the Aegean-Anatolian block. The main pattern of the model velocity field corresponds with the geodetic observations. The extension in the Aegean and the west drift of the Anatolian block can be clearly seen. But locally, deviations still occur. By using a big scale model it is possible to identify the main dynamic processes and necessary constraints and boundary conditions for smaller scale models can be determined.Numéro de notice : 68821 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62020 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 68821-01 30.82 Livre Centre de documentation Géodésie Disponible
Titre : Zur Geokinematik im sächsischen Vogtland Titre original : [Pour la géocinématique dans le pays saxon de Bailli] Type de document : Thèse/HDR Auteurs : J. Wendt, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1999 Collection : DGK - C Sous-collection : Dissertationen num. 517 Importance : 124 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9555-7 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Allemagne
[Termes IGN] analyse comparative
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données GPS
[Termes IGN] système de référence géodésique
[Termes IGN] système linéaire
[Termes IGN] triangulation d'autres pays
[Termes IGN] triangulation localeIndex. décimale : 30.82 Applications géophysiques de géodésie spatiale Résumé : (Auteur) The Saxon Vogtland is a part of the seismic region VogtIand/NW Bohemia. Most of the seismic energy of this region is released during earthquake swarms. Up to now the cause of these events is nearly unknown. Geodetic measurements and evaluation methods are useful to investigate possible recent horizontal deformations of the earth crust in this region. An epoch comparison is performed on the basis of a triangulation at the epoch 1963 and relative GPS measurements of the same triangulations stations at the epoch 1995. A possible method to homogenize the data is described based on the analysis of the heterogeneous data. The strain analysis is applied with respect to further geoscientific indications. Special attention is paid to the geodetic datum problem. A pragmatic strategy to derive invariant deformation parameters is used. The power as well as the limits of such an analysis are discussed considering the available input material. The parameter estimation is an ill-posed problem. One looks for a special least squares solution of an inhomogeneous overdetermined inconsistent system of linear equations with no full rank. Restrictions to the identification of the parameters are introduced to attain estimable functions. Statistical tests complete the mathematical model of the deformation analysis. Numéro de notice : 53912 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=59548 Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 53912-02 30.82 Livre Centre de documentation Géodésie Disponible 53912-01 30.82 Livre Centre de documentation Géodésie Disponible GPS and DORIS combined geocenter motion from reference frame time series analysis / Patrick Sillard (07/05/1998)
PermalinkPermalinkPermalinkPermalinkTectonic interpretation of the Papua New Guinea region from repeat satellite measurements / K. Mobbs (1997)
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