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Although there are different approaches and models to understand and interpret the structures in crustal deformations, one of them is the block modeling method. Using block modeling, one can determine plate movements, parameters such as slip rates, locking depths or Euler poles on faults. However, the accuracy of the block modeling results is related to how well the block boundaries are determined. One of the most important steps of block modeling is the detection of block boundaries and clustering can be used as a tool for this. Cluster analysis assigns data to similar groups based on similarities and differences in the data subject to clustering. In this study, Türkiye was determined as the study area. In this context, we utilized the ensemble clustering algorithm to cluster recent Global Navigation Satellite Systems (GNSS) velocity field in Türkiye and determine block boundaries. Current GNSS velocity field, which consists of 78% survey and 22% continuous type GNSS data processed together, used for clustering analysis for the first time in this study. Before clustering, we employed three different methods - Davies-Bouldin, Gap statistics, and Silhouette - to determine the optimal number (cluster number that best fit to GNSS velocity field) of clusters. Then, k-means, HAC, and spectral clustering techniques were then applied to cluster current GNSS velocities. Finally, we utilized the Meta-Clustering Algorithm (MCLA) as an ensemble clustering technique to cluster the horizontal components of the current velocity domain and present our findings. [ABSTRACT FROM AUTHOR]

In this study, to measure usability and accuracy performances of web-based online GNSS processing services in crustal deformation studies is aimed. In this scope, for the determination of co-seismic and early post-seismic deformations of Van earthquake, October 23th, 2011, the observation data of 12 GNSS stations which belong to TUSAGA-Active network in the earthquake zone were analyzed with AUSPOS, OPUS, and CSRS-PPP from web-based online processing services. In order to examine the accuracy performances of web-based online processing services, the data of the same stations were processed using GAMIT/GLOBK software and the horizontal co-seismic and early post-seismic deformations were determined and the results were compared. When the difference between horizontal deformations required from GAMIT/GLOBK software and the online processing services were examined. The results showed that the differences are statistically insignificant and the displacement vector sizes and directions are compatible. In addition, two-dimensional strain analysis was performed by using horizontal deformations obtained by both solutions. As a result of the strain analysis, it was seen that the main strain parameters obtained from the solutions were generally compatible and the differences between the principal strain parameters were below the value of 0.04 µstrain. According to the results obtained, it was found that the coordinate solutions of the continuous stations obtained by the web-based online evaluation services, were highly accurate to be used in crustal deformation studies.Keywords: Web Based Online GNSS Processing Service, October 23th 2011 Van earthquake, Co-seismic and Post-seismic Deformation, Strain Analysis, GAMIT/GLOBK [ABSTRACT FROM AUTHOR]