First Results for the Selection of Repeating Earthquakes in the Eastern Tien Shan (China)

This research is the first stage of seeking repeating earthquakes sequences (RES) in the modern orogeny active zones. The main idea is to find the possible influence of space weather parameters on the seismic process. This is the reason why I am interested in the satellite CSES-01 data. It is a tool that has monitored Earth’s seismo-electromagnetic activity since 2018. Presuming the “ionosphere-atmosphere-lithosphere” relation exists, it is necessary to involve both satellite and ground-based observational data. The seeking of the triggering mechanism still requires additional analysis of consistent geophysical ground-based networks (geomagnetic and seismic). The stations’ coordinates and instruments are presented. In this work, an earthquake catalog (NEIC) of 400 earthquakes with 2.5+ magnitude from 2015 to 2020 was used. The earthquakes epicenters are illustrated on Google Earth basemap (Landsat image) with geologic linear faults. It could help to find any correlation with relief surface or shear zones, which could be areas of nucleation. Some earthquake clusters were found in the Eastern Tien Shan (region of China), on the border with Kazakhstan and Kyrgyzstan, due to the K-means algorithm. Clustering helps group earthquakes into small families for further cross-correlation of seismic waveforms and the best match selection between the neighbors.

Commentary on morphometric map of characteristic features of relief surface in Nakhchivan Autonomous Republic

The article discusses the features of surface fragmentation in the territory of the Nakhchivan Autonomous Republic. For this purpose, vertical and horizontal fragmentation maps of the area were compiled using Arg GIS technology. The maps were visually analyzed. At the same time, a table was compiled based on the quantitative indicators obtained during the mapping. In this table, quantitative indicators have been replaced by appropriate quality indicators. Here, five quality indicators were obtained for horizontal fragmentation and four for vertical fragmentation. Quality indicators will help to obtain more detailed information about the area. Key words. Arg GİS, horizontal fragmentation map, vertical fragmentation map

Commentary on morphometric map of characteristic features of relief surface cones of right arms of Khur

The article discusses the fragmentation processes and features in the areas where the right tributary of the Kura River collapses. For the study, ArcGis software mapped the area horizontally and vertically at a scale of 1: 750 000, and morphometric indicators were analyzed in units of quantity. According to the indicators, the plain area is grouped into weak, medium, moderate and high, taking into account the plainness as the main factor. Key words: ArcGis, horizontal splitting, vertical splitting, bringing cone, morphometric indicato

Formation Mechanism for Upland Low-Relief Surface Landscapes in the Three Gorges Region, China

Extensive areas with low-relief surfaces that are almost flat surfaces high in the mountain ranges constitute the dominant geomorphic feature of the Three Gorges area. However, their origin remains a matter of debate, and has been interpreted previously as the result of fluvial erosion after peneplain uplift. Here, a new formation mechanism for these low-relief surface landscapes has been proposed, based on the analyses of low-relief surface distribution, swath profiles, χ mapping, river capture landform characteristics, and a numerical analytical model. The results showed that the low-relief surfaces in the Three Gorges area could be divided into higher elevation and lower elevation surfaces, distributed mainly in the highlands between the Yangtze River and Qingjiang River. The analyses also showed that the rivers on both sides of the drainage divide have not yet reached equilibrium, with actively migrating drainage divides and river basins in the process of reorganizing. It was concluded that the low-relief surfaces in the Three Gorges area did not share a common uplift history, and neither were they peneplain relicts, but rather that the effect of “area-loss feedback” caused by river capture has promoted the formation of upland low-relief surface landscapes. A future work aims to present the contribution of accurate dating of low-relief surface landscapes.

Propagating uplift controls on formation of low-relief, high-elevation surfaces in the SE Tibetan Plateau

<p>The SE Tibetan Plateau has extensive broad, low-relief, high-elevation surfaces perched above deep valleys, as well as in the headwaters of the three rivers (the Salween, the Mekong, and the Yangtze). However, understanding the presence of these low-relief surfaces is a long-standing challenge because their formation process remains highly debated. While alternate mechanisms have been proposed to explain the low-relief surface formation in this setting (e.g., drainage-area loss mechanism due to horizontal advection; Yang et al., 2015, Nature), a long-standing hypothesis for the formation of low-relief surfaces is by a step change in uplift and incision into a pre-existing, low-relief surface (Clark et al., 2006, JGR; Whipple et al., 2017, Geology).</p><p>The morphology of low-relief surfaces in the SE Tibetan Plateau is largely consistent with formation by a step change in uplift, but one problem with this model is that low-relief surfaces formed by a step change in uplift are relatively short-lived, since they are incised and steepened by erosion, which sweeps upstream at the response time of mountain ranges (in the order of several million years). Using a landscape evolution model that combines erosion, sediment transport and deposition processes (Yuan et al., 2019, JGR), we demonstrate that propagating uplift form large parallel rivers, with broad low-relief, high-elevation interfluves that persist for tens to hundreds of million years, consistent with various dated ages. These low-relief surfaces can be long-lived because the drainage areas in these interfluves are insufficient to keep up with rapid incision of the large parallel mainstem rivers. Our simulated features match various observations in the SE Tibetan Plateau: (i) low-relief surfaces are approximately co-planar in headwaters, and decrease in elevation smoothly from northwest to southeast across the plateau margin; (ii) χ-elevation plots of the mainstem rivers are convex; (iii) low-relief surfaces have low erosion rates; and (iv) erosion rates are high in the mainstem rivers at the propagating margin.</p>

Basement influence on formation of the East European platform latest structure

Structural and geomorphological researches of the most part of the East European platform revealed arch-block style of the latest dislocations. 3D geodynamic modeling showed direct correlation (To =0, 26) of the basement structures with the modern relief surface that demonstrates direct geodynamic basement influence on the cover structure of the platform. The calculated newest tension field for the territory of Central Russian Height, Klin-Dmitrov Ridge, Meshersky and Oka-Donskoy depressions allowed to establish the sites closed to mechanical destruction and are seismodangerous.

The influence of the cooling method on high performance cutting of the AlZn5.5MgCu alloy

The research of the high performance cutting of the aviation aluminum alloy was conducted. Four methods of the cooling delivery: flood, internal, on rake surface, on the relief surface, were applied. The influence of the cooling method on the cutting forces component and vibration amplitude was presented.