Glacier Runoff Variation Since 1981 in the Upper Naryn River Catchments, Central Tien Shan

Water resources in Central Asia strongly depend on glaciers, which in turn adjust their size in response to climate variations. We investigate glacier runoff in the period 1981–2019 in the upper Naryn basin, Kyrgyzstan. The basins contain more than 1,000 glaciers, which cover a total area of 776 km2. We model the mass balance and runoff contribution of all glaciers with a simplified energy balance melt model and distributed accumulation model driven by ERA5 LAND re-analysis data for the time period of 1981–2019. The results are evaluated against discharge records, satellite-derived snow cover, stake readings from individual glaciers, and geodetic mass balances. Modelled glacier volume decreased by approximately 6.7 km3 or 14%, and the majority of the mass loss took place from 1996 until 2019. The decreasing trend is the result of increasingly negative summer mass balances whereas winter mass balances show no substantial trend. Analysis of the discharge data suggests an increasing runoff for the past two decades, which is, however only partly reflected in an increase of glacier melt. Moreover, the strongest increase in discharge is observed in winter, suggesting either a prolonged melting period and/or increased groundwater discharge. The average runoff from the glacierized areas in summer months (June to August) constitutes approximately 23% of the total contributions to the basin’s runoff. The results highlight the strong regional variability in glacier-climate interactions in Central Asia.

Geodetic Mass Balance of Haxilegen Glacier No. 51, Eastern Tien Shan, from 1964 to 2018

The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Tien Shan, China) is one of the very few well-measured glaciers, and comprehensive glaciological measurements were implemented from 1999 to 2011 and re-established in 2017. Mass balance of Haxilegen Glacier No. 51 (1999–2015) has recently been reported, but the mass balance record has not extended to the period before 1999. Here, we used a 1:50,000-scale topographic map and long-range terrestrial laser scanning (TLS) data to calculate the area, volume, and mass changes for Haxilegen Glacier No. 51 from 1964 to 2018. Haxilegen Glacier No. 51 lost 0.34 km2 (at a rate of 0.006 km2 a−1 or 0.42% a−1) of its area during the period 1964–2018. The glacier experienced clearly negative surface elevation changes and geodetic mass balance. Thinning occurred almost across the entire glacier surface, with a mean value of −0.43 ± 0.12 m a−1. The calculated average geodetic mass balance was −0.36 ± 0.12 m w.e. a−1. Without considering the error bounds of mass balance estimates, glacier mass loss over the past 50 years was in line with the observed and modeled mass balance (−0.37 ± 0.22 m w.e. a−1) that was published for short time intervals since 1999 but was slightly less negative than glacier mass loss in the entire eastern Tien Shan. Our results indicate that Riegl VZ®-6000 TLS can be widely used for mass balance measurements of unmonitored individual glaciers.

The Complex of Experimental Facilities for the Cosmic Ray Investigation at the Tien Shan Mountain Station

The study describes the experimental complex of the station located in the Tien Shan mountains at an elevation of 3340 m above sea level. The complex consists of detectors of different types scattered across the station area, such as scintillation particles detectors, Cherenkov detectors, radio emission detectors for the measurement of the electron component of extensive air showers (EAS) created by the (1–1000) PeV cosmic ray particles, an ionization calorimeter and neutron detectors for the study of the nuclear-active component of EAS cores, and the underground particle detectors for the detection of cosmic ray muons. The data acquisition system allows the simultaneous recording of parameters from various stand-alone detectors registering an EAS, and storage of the acquired data in the database. As an illustration of research capability, the results of the EAS study are presented here which were obtained during the last few years at the different experimental set-ups constituting the Tien Shan complex.

Route measurements of natural surface radiation background in the Almaty region

Measurements of the spatial distribution of radon isotopes were carried out from April 2021 to August 2021 in the foothills of the Trans-Ili Alatau of the Tien Shan in the Almaty region at various heights above sea level: from 500 to 2500 meters. They were carried out using electronic radiometric equipment: beta-dosimeter “RKS-01B-SOLO”; gamma dosimeter “RKS-01G-SOLO”; radiometer of radon and its daughter decay products “RAMON- 02” in the field. As a result, preliminary assessment schemes were built for route measurements of the 222Rn radon isotope, beta and gamma radiation fields from natural daughter products of decay of radon isotopes and radionuclides located in the surface atmospheric layer.

Features of the Tien Shan newest orogen morphostructure

Research subject. The concept of morphostructure implies the presence of a relationship between the relief forms of segments of the Earth’s crust and their structural and material content. This article describes the geological ensembles of the Tien Shan orogen, the tectonic structure and modern relief of which differ in their parameters from the general morphostructural plan and which, therefore, belong to the category of morphostructural anomalies. Materials and methods. The data presented in the article were obtained in the course of field structural-geological and morphostructural study of key segments of the Tien Shan orogen, as well as an analysis of materials from previous research, including the results of geophysical sounding of the Earth’s crust and geodesical monitoring of relative modern movements of reference points on the surface.Results. The article demonstrates that, against the background of the general linear-wave morphostructure of the Tien Shan orogen, there are areas whose relief and tectonic structure do not agree with the general tectonic plan of the mountain. Wi thin the considered region, different types of morphostructural anomalies are identified and described, reflecting the speci fics of the evolution and geotectonic position of individual volumes of upper-crust rock complexes: zones of concentrated deformation and tectonic joining; centrally symmetric structures formed on the site of paleoatolls; neotectonic protrusions of the granite basement; trans-regional zone of the Talaso-Ferghana Fault and other structures. Conclusion. The formation of morphostructural anomalies is associated with the presence of non-trivial geodynamic environments operating against the background of the tectonic regime common to the Tien Shan. The modern morphostructure of the Tien Shan is the result of interference between various geodynamic regimes and settings: a regime common to the entire territory of the orogen and particular regimes that manifest themselves sporadically and are reflected in the modern relief.

Biodiversity of Fishes of River Ecosystems of the Western Tyan-Shan

The paper cites data on the biological diversity of fishes in the river ecosystems of the Western Tien Shan. Data on the diversity and distribution of species are presented and analyzed. The role of various factors affecting the variability of species numbers and their range is discussed, which is important for development of a number of measures on conservation of rare and vanishing fish species.

Nazugum, a new 4000 year old rockshelter in the Ili Alatau, Tien Shan

The PALAEOSILKROAD project has been conducting field surveys in Kazakhstan to explore the regional Palaeolithic record by targeting primarily caves and rockshelters. However, the survey also discovered numerous sites that were occupied during the Holocene. In this paper, we present our preliminary findings from the Nazugum rockshelter, a new archaeological site located in south-eastern Kazakhstan (Almaty region). The stratigraphic sequence demonstrates the transition from fluvial channel deposits without artifacts to aeolian loess deposits with lithics, charcoal remnants, and fragments of animal bones. The lithics recovered from the sediment wall are dominated by bladelet technology, characteristic for Holocene assemblages. Radiocarbon dates from adjacent charcoal samples yielded an age of 2461-2347 cal. years BC attributing the human occupation to the transitional period of late Eneolithic and early Bronze Age. Our study provides new data for the use of rockshelters in Kazakhstan during the late Holocene and lays the groundwork for future salvage work in Nazugum rockshelter due to the active erosion of the archaeological record.

Glacier Area and Snow Cover Changes in the Range System Surrounding Tarim from 2000 to 2020 Using Google Earth Engine

Glacier and snow are sensitive indicators of regional climate variability. In the early 21st century, glaciers in the West Kunlun and Pamir regions showed stable or even slightly positive mass budgets, and this is anomalous in a worldwide context of glacier recession. We studied the evolution of snow cover to understand whether it could explain the evolution of glacier area. In this study, we used the thresholding of the NDSI (Normalized Difference Snow Index) retrieved with MODIS data to extract annual glacier area and snow cover. We evaluated how the glacier trends related to snow cover area in five subregions in the Tarim Basin. The uncertainty in our retrievals was assessed by comparing MODIS results with the Landsat-5 TM in 2000 and Landsat-8 OLI in 2020 glacier delineation in five subregions. The glacier area in the Tarim Basin decreased by 1.32%/a during 2000–2020. The fastest reductions were in the East Tien Shan region, while the slowest relative reduction rate was observed in the West Tien Shan and Pamir, i.e., 0.69%/a and 1.08%/a, respectively, during 2000–2020. The relative glacier stability in Pamir may be related to the westerlies weather system, which dominates climate in this region. We studied the temporal variability of snow cover on different temporal scales. The analysis of the monthly snow cover showed that permanent snow can be reliably delineated in the months from July to September. During the summer months, the sequence of multiple snowfall and snowmelt events leads to intermittent snow cover, which was the key feature applied to discriminate snow and glacier.

RECONSTRUCTION ON THE VOLTAGE OF THE PRE-SLIDING STATE OF THE TRAGICHOUS MOUNTAIN SLOPE LANDSCAPE «AK KAIN»

The method of reconstruction and investigation of the pre-landslide condition of the tragic landslide «Ak-Kain» of the Northern Tien Shan is proposed. A model and a finite element algorithm for studying the stress-strain state (VAT) of soil sediments of an obliquely layered structure are briefly presented. The established zones and places of accumulation of dangerous stress concentrations along the inclined layer that led to the tragedy are shown. The plots show the found other areas of hazardous stress concentrations prone to destruction.