Time Distribution of Strong Seismic Events in the Fore-Sudetic Monocline in Context of Signals Registered by Water-Tube Gauges in Ksiaz Geodynamic Laboratory.

Changes in the stress field in Swiebodzice Depression (SU) unit area are the reason of complex kinematics of the rock blocks consisting of rotations and horizontal/vertical displacements. The measurement system of the Geodynamic Laboratory in Ksiaz, associated with rock blocks which are separated by faults, is a natural detector of tectonic activity. Installed in laboratory long water-tube gauges allowing to determine the functions of tectonic activity-TAF, and their derivatives. A comparison of the TAF with the seismic activity of the Fore-Sudetic Monocline showed that the strong seismic shocks (magnitude ≥3.6) occur in the Monocline only during defined and repeatable phases of the kinematic activity of the SU. Observed concordance proves the thesis of the existence of a large-scale, and largely homogeneous field of tectonic forces which, at the same time, cover the SU and the Fore-Sudetic Monocline units. The results of comparison between seismic events temporal distribution and phases of tectonic activity of the SU orogen indicate existence of the time relation between function of derivative of the tectonic activity (TAF) and seismic events.

Assessment of radon transportation and uranium content in the tectonically active zone of Himalaya, India.

The study shows how geology and tectonic activity affect the soil gas 222Rn concentration. The tectonically active zone, namely the Ghuttu region, which is located within the Himalayan seismic belt, was studied to decipher its impact on soil gas 222Rn concentrations. A soil gas 222Rn study was performed in the soil at a depth of 30 cm, and it varied from 426 ± 156 Bq m-3 to 24,057 ± 1110 Bq m-3 with an average of 5356.5 ± 1634.6 Bq m-3, and at 60 cm below the soil surface, the concentration varied from 1130 ± 416 Bq m-3 to 30,236 ± 1350 Bq m-3 with an average of 8928.5 ± 2039.5 Bq m-3. These concentrations vary in soil from -3.4 % to 437.3 % as the depth moves from 30 cm to 60 cm. The variation in uranium content also shows anomalies, and higher values of uranium content in the soil affect the radon concentration in the study area. The average soil gas 222Rn concentration in the Ghuttu window was found to be higher than that in its surrounding region. This is likely due to transportation from daughter products of uranium. 222Rn mass exhalation rate measurements were also carried out, and a weak correlation with the soil gas 222Rn concentration was observed. A significant variation in the mass exhalation rate was noticed in tectonically active areas. This study is vital to understanding the behavior of radon and uranium in tectonic regions.

Evaluation of relative active tectonics by using geomorphic indices of the Bamo anticline, Zagros Fold-Thrust Belt, Kurdistan Region of Iraq.

The Mountain Front Flexure forms a prominent morphotectonic structures along the Zagros Fold-Thrust Belt (ZFTB). It consists of several segments that defines tectonic salients and recessions within the belt. These segments are separated by strike-slip faults, including Khanaqin fault, which forms the boundary between the Kirkuk embayment and Lurestan Arc. The Bamo anticline is a complex N-S trending structure located above the Khanaqin fault zone, and it is thought to manifest active deformation in the Zagros Fold-Thrust Belt and along the fault. This study examines the state of active tectonics along the Bamo anticline through quantitative analyses of the evolved landscape using geomorphic indices. For that reason, six indices have been chosen for the analysis, such as stream length-gradient index (SL), drainage basin asymmetry (AF), hypsometric integral and hypsometric curve (HI & HC), ratio of valley-floor width to valley height (VF), basin shape (BS), and mountain front sinuosity (Smf). Each index's results were categorized into three classes, and the results from the first five indices, excluding Smf, were integrated to get the index of relative active tectonics (IRAT). This index was then compared with the results of Smf to assess the relative active tectonics (RAT) along the anticline. The results of the IRAT, classified into four classes from very high to low tectonic activity, reveal that no area is classified as class 1 (very high activity). However, 38% and 56% of the region are categorized as classes 2 (high activity) and 3 (moderate activity), respectively. Furthermore, the remaining 6% of the research area exhibits class 4 (low activity). The Smf values for the Northern, Middle, and Southern segments of the anticline are 1.12, 1.18, and 1.27, respectively. Consequently, based on the Smf data, all mountain fronts are classified as class 2 (moderate tectonic activity.

Testing of 222Rn application for recognizing tectonic events observed on water-tube tiltmeters in underground Geodynamic Laboratory of Space Research Centre at Ksiaz (the Sudetes, SW Poland).

Research on relationships between variation in 222Rn activity concentration and tectonic events recorded using the instruments of the Geodynamic Laboratory of SRC PAS at Ksiaz (the Sudetes, SW Poland) had been conducted since 2014. The performed analyses of variation have demonstrated the spatial character of changes in 222Rn activity concentration. Their time-course is comparable in all parts of the underground laboratory. This means that gas exchange between the lithosphere and the atmosphere occurs not only through fault zones but also through all surfaces of the underground workings: the floors, the sidewalls and the roofs. Further, some relationships between 222Rn activity concentration and tectonic activity of the orogen have been demonstrated with the use of Pearson's linear correlation coefficient. The comparison between temporal distribution (times series) of radon activity concentration and water-tube tiltmeters (WTs) demonstrated that radon data have regular oscillations which can be approximated using the sine function with a 12 month cycle (seasonal changes) and amplitude in the range of 1000-1500 Bq/m3. To compare the collected radon signal data and tectonic activity, we used linear function as the simplest method of trend assessment. Pearson's correlation coefficient r cannot be accepted as appropriate for assessing the interdependencies between variables because they do not have a normal distribution, and the relationship between them is not linear. It was noted that each series of data, namely radon activity concentration and tectonic activity determine the series of deviations above and below the trend function. Because of the non-fulfillment of the above assumptions, we used nonparametric equivalents such as Spearman's rank correlation coefficient rs and Kendall's tau. The obtained results showed that the value of the rs coefficient ranges from 0.38 to even 0.43. The best relationship at the level of rs = 0.43 was determined between the radon activity concentration recorded by detector no. 3 and the tectonic activity of the rock mass registered on the WT-2 channel. Similar at the rs level of 0.37-0.38 between detector no. 5 and 4 and the WT-2 channel. A bit higher than rs = 0.39 between detector no. 3 and the WT-2 channel. In each case, these were positive correlations. The obtained Spearman's rs coefficients indicate the correlation between 222Rn activity concentration and tectonic activity of the rock mass. The t-statistic, which analyzes the significance of Spearman's coefficient rs is a descriptive measure of the accuracy of regression matching to empirical data. It takes values in the range of percentage and provides informations about which part of the total variability of the radon activity concentration (Y) observed in the sample has been explained (determined) by regression in relation to tectonic activity of the rock mass (X). In our case, approximately f 40% to more than 50% of the radon activity concentration (Y) was explained by regression in relation to the tectonic activity of the rock mass. We obtained similar results with the use of Kendall's tau coefficient. Precise description of the character of this relationship requires further, more detailed analyses, such as comparing characteristics of the distributions based on trend variation like Monte Carlo simulation, Multivariate Adaptive Regression Splines or neural networks.