Northeast Direction Research Articles

Опыт по развитию территории и использованию земельных ресурсов в китайской северо-восточной провинции Цзилинь

A review of the experience of using land resources in the Chinese northeastern province of Jilin as part of the implementation of projects to develop the territory of the old industrial base in northeastern China shows that the PRC government pays special attention to the strategically important border area. The development of the territory in Jilin Province is carried out in accordance with the updated regional coordinated development strategy adopted in 2012 in the PRC, the development strategy of the main functional regions, the new urbanization strategy and the rural revitalization strategy. The tasks of coordinating the growth of urban areas and protecting cultivated lands come to the forefront. The Chinese authorities associate the further implementation of the policy of “openness” with Jilin Province in the northeast direction. The efficient use of land resources in the province is regulated by a whole complex of legal and regulatory frameworks. Jilin puts forward clear goals for the construction of regional infrastructure focused on protecting the environment, optimizing rural settlements, promoting urbanization, modernizing transport and logistics routes, and protecting key energy and water resources. Since 2021, the main projects of spatial transformations have been implemented in the province: the project of spatial placement and construction of industrial facilities “one base – six pairs” and the project of an integrated structure for the protection and spatial development of the territory of the province “one circle, two barriers, three zones, four axes.”

Identifying source apportionment of atmospheric particulate matter and gaseous pollutants using receptor models : A case study of Bengaluru, India

The data of Particulate matter PMs (PM2.5, PM10) and Gaseous Pollutants such as carbon monoxide (CO), methane (CH4), oxides of nitrogen (NOx: NO and NO2), non-methane hydrocarbons (NMHCs), sulfur dioxide (SO2), along with ammonia (NH3) at five different locations across Bengaluru from 1st January, 2017 to 20th March, 2018 were collected. The primary objective of this research work is to identify the sources of atmospheric particulate matter and gaseous pollutants using receptor models in Bengaluru, India. To execute this, receptor models, namely Conditional Bivariate Probability Function (CBPF) and Concentrated Weighted Trajectory (CWT) Analysis, are applied. Conditional Bivariate Probability Function (CBPF) shows that, annually, the maximum concentrations of PMs over receptor sites were detected during low wind speed (< 2 knots) along the north-east direction specifying that the long-range transport does not play an essential role in the transportation of higher concentrations of PM and their primary source region may be localized. Concentrated Weighted Trajectory (CWT) analysis shows that, seasonally, the highest air mass contribution of about 37% was noticed in summer, whereas the lowest was in the post-monsoon season (13%). The significant contribution of PM2.5 transported from long distances was during monsoon, and in the case of PM10, it was in summer. The study suggests that the long-range transport of PMs and gaseous Pollutants was not vital and was observed to be localized.

Spatial correlation-based machine learning framework for evaluating shale gas production potential: A case study in southern Sichuan Basin, China

Assessment of production potential and prediction of sweet spots in unexploited shale gas wells are crucial technologies for achieving a high success rate in drilling. Most existing methods are only applicable for yield forecasting of shale gas wells with known geological and drilling/completion factors after production. In addition, the shale gas reservoir in the Longmaxi Formation in the southern Sichuan Basin of China is characterized by low porosity, low permeability, and diverse gas reservoir states. Thus, forecasting production from unexploited wells and predicting the exact location of the sweet spot under complex geological conditions have become challenging topic for both academia and industry. According to the first law of geography, shale gas wells that are closer in space have more similar geologic features. Based on this foundation, a machine-learning prediction model based on spatial correlation (SC-MLPM) is proposed for evaluating potential production of shale gas wells in the Changning play located in Longmaxi Formation in the southern Sichuan basin, China. Specifically, an improved K-nearest neighbor algorithm (SC-KNN) based on the spatial correlation characteristics of the exploited wells is designed to estimate the relevant geological factors of the unexploited wells in the same area. In addition, an extreme gradient lifting model based on Huber loss function (Hu-XGB) is developed to predict the potential production of unexploited shale gas wells, and then the shale gas sweet spot area in the research area is predicted quickly and accurately. The experimental results on 88 shale gas wells from Changning play show that the mean relative error of the prediction results of the proposed method is 9.8%. Furthermore, the results also determine that the sweet spots of shale gas wells in the research area are mainly developed in the northwest and northeast directions, and gradually become worse in the southeast direction. Eventually, experimental results for the Fox Creek play in Canada show that the proposed model obtains better predictive performance as the number of gas wells increases, and also verifies the generalizability. This work provides a basis for the efficient development of the research area.

Eastern Continental Divide Origin in the Blacksburg, Virginia Area Determined by Topographic Map Interpretation, USA

Published geology literature addresses only a small fraction of the Blacksburg, Virginia region topographic map drainage divide evidence. This situation probably arises because the accepted geology and glacial history paradigm (accepted paradigm) does not explain most topographic map drainage divide evidence (anywhere). A new and fundamentally different geology and glacial history paradigm (new paradigm) which appears to explain most topographic map drainage divide evidence sees the Eastern Continental Divide in the Blacksburg area as being located along the rim of a continental ice sheet created and occupied deep “hole” with the rim being uplifted as immense and prolonged southwest-oriented meltwater floods flowed across the region. From the new paradigm perspective northwest-oriented New River valley headward erosion into the rising deep “hole” rim (from the deep “hole”) upon reaching the Blacksburg region beheaded and reversed southwest-oriented floodwaters (probably aided by deep “hole” rim uplift) to create today’s northeast- and northwest-oriented New River. Headward erosion of the southeast-oriented Roanoke River valley and subsequently the southeast-oriented James River valley (both from the Atlantic Ocean) then created the Roanoke River-New River and James River-New River drainage divides (both are Eastern Continental Divide segments) and the James River-Roanoke River drainage divide by beheading and reversing southwest-oriented floodwaters which had been flowing in diverging and converging channels (which had been eroded headward in northeast directions along less resistant bedrock units from the New River valley). This scenario explains most through valleys (valleys crossed by drainage divides), barbed tributaries, river direction changes, and water gaps seen on Blacksburg area detailed topographic maps and does not see significant changes taking place since the southwest-oriented floods ended. The accepted and new paradigms are incommensurable which according to Thomas Kuhn means one paradigm should not be used to judge the other.

Study on Spatial and Temporal Characteristics of Construction Land Expansion in Hohhot City Center, 1992-2022

Based on CLCD LULC data, this paper uses the ArcGIS 10.8 platform to analyze spatial data and discusses the expansion rate, expansion intensity, expansion direction, expansion type, and land use structure changes of construction land in Hohhot. The results show that the construction land area of Hohhot increased from 103.02 square kilometers in 1992 to 343.41 square kilometers in 2022, with an average annual expansion rate of 7.75 square kilometers and an expansion intensity index of 7.53. The city's expansion shows a staged character, with 2002 to 2012 as the period of rapid expansion. The direction of expansion is mainly concentrated in the northeast, southeast, east, and southwest directions, which is closely related to the city's economic development, natural conditions, and planning control. In terms of expansion types, infill expansion has dominated from 1992 to 2002, while marginal expansion has dominated from 2002 to 2012 and from 2012 to 2022. The land use structure has changed significantly, with a significant decrease in the area of arable land and grassland, a continuous increase in the area of construction land, and a slight increase in the area of forested land. During the 30 years, 242.51 square kilometers of land of various types have been converted into construction land, with arable land being the most converted, accounting for 71.51% of the total amount of converted land. The study concludes that urban land expansion in Hohhot is characterized by obvious spatial and temporal differences and phases, and strict land management methods need to be implemented to ensure the rationality and sustainability of land use. At the same time, arable land and the ecological environment damaged by urban expansion should be protected and restored through ecological compensation mechanisms.

Earth crust of eastern segment of Ukrainian Carpathians in the regional profile RP-5 zone: structure, geodynamics, oil and gas bearing

The purpose of the work is to present widely to the scientific community and analyze in detail the structure and oil and gas bearing of the Bukovyna lithosphere (the eastern part of the Carpathian region of Ukraine) based on the unique data on the regional RWМ-CDP profile RP-5 and on the neighboring regional profiles with the involvement of other geological and geophysical data. The methodology includes a detailed comprehensive analysis of the deep structure and oil and gas bearing and oil and gas prospects of the region and its separate zones based on seismic data on the regional profile RP-5 and nearby oil and gas bearing and oil and gas prospective areas with the involvement of a complex of geological and geophysical data. Results. In the zone of the profile RP-5, the occurrence of sedimentary strata and covers of the Folded Carpathians, the Carpathian foredeep and the edge of East-European craton in the earth's crust of Bukovyna was traced in detail, including the different depth tiers of the Carpathian thrusts and folds. The stepwise dipping of the edge of the East-European craton below the Carpathians is revealed here (generally similar to other segments of the Ukrainian Carpathians). The presence here of weakly dislocated autochthonous layers of Mesozoic rocks under the Carpathian thrusts is also established. In these horizons, several bands of folds of the Carpathian extension were discovered, some of them, in particular, the Lopushna fold, are associated with discovered oil and gas deposits. The thickening of the horizons of the lower crust under the axial part of the Bukovyna Folded Carpathians was revealed. In the pre-Carpathian part of the profile, there are 2 deepped ancient "seismofocal" zones of different age of formation and different vergence (researched in detail by S.G. Slonytska using special methods), as well as a number of apophysis-like intrusions. As a result of the comprehensive analysis, the influence of the characteristic features of the local Alpine geodynamic process was traced – the Alpine/Carpathian compression of the lithosphere in the northeast direction orthogonal to the Carpathians and the corresponding thrusts of the allochthon on the previously stepwise dipped here in the southwest direction western edge of the East-European craton as a result of rift-like pre-alpine geodynamic processes. Originality. The peculiarities of the deep structure, geodynamics, seismicity and oil and gas bearing of the Bukovyna lithosphere were determined based on the data of the regional profile RP-5, taking into account new data from oil and gas exploration studies in the subregion and data on various components of the geodynamic process in the whole Carpathian region of Ukraine. The oil and gas prospects of a number of deep folds of autochthonous Mesozoic rocks in the subthrust of the Pokuttya-Bukovyna Carpathians have been predicted and confirmed. Practical significance. The research results make it possible to more clearly justify the directions of oil and gas exploration in the subregion.

Local radical chemistry driven ozone pollution in a megacity: A case study

A comprehensive field campaign (STORM) was conducted from October to November 2018 at Peking University Shenzhen Graduate School (DXC, 22.60 °N, 113.97 °E) in Shenzhen, Guangdong Province, to investigate the influence of oxidation on secondary pollution formation under different environmental conditions. Precursor concentrations introduced typical urban characteristics on the modeled OH reactivity (kOH) levels with a broad range between 15.0 and 30.0 s−1. The daily maxima of the observed OH and HO2 radical concentrations were (2.3–12.8) × 106 cm−3 and (1.3–9.1) × 108 cm−3, respectively. Abundant photolysis sources (e.g., HONO, HCHO, and O3) intensified photochemistry in the polluted period, and the OH radical concentration peaked 6.0 × 106 cm−3 at noon (11:00–13:00). A low kOH of 12.0 s−1 in the clean atmosphere prolonged the OH lifetime by decreasing the termination efficiency while maintaining a sustained OH concentration comparable to the polluted period. In terms of meteorology, the dominating air mass was isolated from the east and northeast directions, which promoted the transition of ozone from mild pollution to severe pollution. The immense precursor emissions at urban sites first compensated for the negative effect of declined solar radiation, and then they amplified radical propagation. Simultaneously amplified radical propagation promoted oxidation capacity, and increased the chain length (ChL) from 3.6 to 4.1, and P(O3) has lifted effectively by approximately 13.3 %. Stable wind direction and velocity reduced the physical dilution loss, which supported the fast Ox rise around 16:00. Further detailed investigations are required on the environmental causes of ozone pollution to address the influence of the oxidation processes on secondary pollution formation under other environmental conditions.

Potential environmental pollution study by leachate generation and health risk assessment in the vicinity of bandhwari landfill disposal site, National Capital Region, India

Effects of fast urbanization and development in metropolitan cities is the production of massive amounts of waste from households and industries. Dumping of waste at an unengineered landfill site creates environmental issues. Generated leachate from such landfill is having potential to pollute the surrounding environment including groundwater. To understand the groundwater pollution by the effect of landfill leachate and health risk assessment for humans, four leachate samples and thirty-six groundwater samples were collected from different sources of groundwater from close proximity of Bandhwari Landfill site located in National Capital Region, Delhi. EC and SO42− values of Leachate samples i. e L-1 and L-2 are 42.5 mS/cm and 55.4 mS/cm; 1916.4 mg/l and 1931 mg/l respectively. Leachate pollution Index (LPI) values signifies that landfill leachate is having moderate potential for contamination. The dominance of average ionic species concentration of major cations in groundwater is given as Ca2+>Na+>Mg2+>K+ and major anion as HCO3− > Cl− > SO42− > NO3− > F−. As per Water Quality Index (WQI), 67% of samples lies in excellent category, 17% of samples falling in good category, whereas around 6% of groundwater samples lies in poor category, very poor category and unsuitable category. Landfill leachate and groundwater sample from North East direction are having high concentration of tritium i.e. 8.11 ± 0.40 TU and 3.03 ± 0.29 TU, respectively. Leachate samples from leachate pond-1 and leachate pond-2 are showing quite high Cl−/Br− ratio i. e 342 and 320. 86 respectively. But groundwater samples are exhibiting Cl−/Br− ratio in the range of 173.68 to 108.75. This represents leaching of salts from solid decomposed waste from landfill. Both non-carcinogenic and carcinogenic risk (CRing) were calculated for children and adult. Hazard Index (HI) values are higher than reference value i. e > 1 in the children (in 23% samples) as compare to the adult. These are mainly associated with Co, Cd and Pb. CRing of groundwater sample due to the presence of As, Ni, Cr and Cd falling in the range of 10−6 and 10−4 showing high risk to cancer per 10, 00, 000 million people by ingestion. However there is no significant cancer risk by dermal exposure by all metals in all groundwater samples. Groundwater pollution appears to be limited to the close vicinity in South and North-East direction.

Spatial patterns of PM2.5-bound heavy metals and analysis of their influencing factors in China

This study investigates the relationship between the spatial distribution patterns of heavy metals (HMs) in atmospheric fine particulate matter (PM2.5) and their influencing factors in China, in order to address air pollution problems. Using HM data from PM2.5 collected from 88 Chinese cities between 2012 and 2020, the study employed a combination of enrichment factor (EF) analysis, standard deviation ellipses and hot spot analysis to assess spatial distribution patterns; geographical detectors to identify influencing factors; and hybrid single-particle Lagrangian integrated trajectory models (HYSPLIT) to determine air mass movement. The results reveal that the spatial distribution of PM2.5-bound HMs in China is characterized by high levels in the north and interior and low levels in the south and along the coast. Anthropogenic activities affect HM levels in China's interior more strongly than on the coast. Moreover, the distribution of PM2.5-bound HMs in China exhibits a northeast-southwest spatial pattern, with significantly higher levels observed in central and northern regions than in eastern regions, particularly along the coast. Industrial waste emissions and energy consumption are key factors contributing to high PM2.5-bound HMs. In central China, the summer air mass movement predominantly follows a southeast direction, while in winter, it follows a northwest direction, originating from inland. In contrast, in eastern China, summer air mass movement predominantly follows a southeast direction, while in winter, it follows a northeast direction, originating from the ocean. Overall, our findings suggest that HMs in PM2.5 display high clustering values in central China, due primarily to industrial waste emissions, energy consumption, and air mass movement.

Pollution characteristics of peroxyacetyl nitrate in karst areas in Southwest China

In recent years, the issue of photochemical pollution in the Guangxi region of China has escalated considerably. However, there remains a notable dearth of related research in this area. Peroxyacetyl nitrate (PAN), recognized as a reliable indicator of photochemical pollution, was the focus of our study. This study marks the inaugural observation of PAN levels in Guilin, a renowned world tourist destination situated in a typical karst region, during 1–31 October 2021. Throughout this observation period, the average volume concentration of PAN ranged from 0.087 to 2.559 ppb, which was 3.61 times higher than the South China background site of the Nanling. Combined with meteorological factors and potential source analysis, the causes of a typical high-value PAN process were explored during 24–29 October. The results showed that, during this high-value PAN event, pollution primarily originated from the horizontal transport of polluted air masses and the descent of high-altitude air masses from Hunan Province in the northeast direction. Additionally, the meteorological conditions, including high temperatures, intense radiation, and low humidity, fostered local PAN formation. Notably, traffic emissions emerged as the primary source of PAN's locally generated precursor volatile organic compounds. Furthermore, we estimated the background concentration of O3 to be approximately 20.347 ppb based on PAN monitoring data, constituting 44.4% of the total O3 levels in Guilin City. This study offers valuable insights for addressing and mitigating photochemical pollution in southern Chinese cities, while providing a theoretical foundation for regional pollution control efforts.摘要桂林是世界著名的地处喀斯特地区的旅游胜地, 其光化学污染问题日益严重.过氧乙酰硝酸酯(PAN)被认为是光化学污染的可靠指标, 也是本研究的重点. 本研究于2021年10月首次观测了桂林的PAN的浓度为0.087–2.559 ppb, 同时探讨了PAN典型高值过程的成因. 此次污染主要来源于东北方向污染气团的水平和高空输送, 同时, 高温, 强辐射和低湿度等气象条件也促进了本地PAN的形成. 本研究同时估算了桂林市的O3背景浓度为20.347 ppb.这项研究为城市的光化学污染控制工作提供了理论基础.

Analysis of Formation Ronggojalu Spring and Probolinggo Active Fault Continuity with Satellite Data Gravity Method

The Ronggojalu spring, with a discharge intensity of more than 3,000L/second, makes it one of the spring with the most significant discharge in Indonesia and is the main supplier of clean water for the City of Probolinggo. From the observation of topographic maps, the existence of this spring forms a lineament with Paras Spring and Sumber Kramat with a direction of Northeast to Southwest. The presence of this lineament can indicate the existence of geological structures that play a role in the formation of spring. In addition, this lineament is in the same direction as the active Probolinggo fault identified by PUSGEN (Pusat Studi Gempa Nasional). This study aims to identify the presence of geological structures in the lineament using satellite gravity data GGMplus (Global Gravity Model) and Remote Sensing. This data is quite efficient and effective in identifying subsurface geological structures. With the SVD (Second Vertical Derivative) analysis, the residual anomaly results from the second derivative value of the Bouger anomaly so that it can show the density contrast value as an indication of the geological structure. From the results of the interpolation of satellite gravity data in the study area, the CBA (Complete Bouguer Anomaly) value range is -16.8 – 4.8 mGal. The analysis of SVD and FHD shows a significant contrast different values along the fault line that passes through the spring. The lineament density processing also shows a weak zone around the fault zone, indicating the continuity in that zone. The existence of a fault under this spring indicates the influence of the fault on the formation of Ronggojalu Spring, Paras Spring, and Keramat Spring. In addition, it is estimated that this fault is a continuation of the active Probolinggo fault.

The Influence of Southeastern South American Rainfall on Weather Patterns Over the Tropical Atlantic, Northwestern Africa and Western Europe

AbstractDuring boreal winter (December–February), the South American monsoon system (SAMS) reaches its annual maximum when upper‐tropospheric westerly winds prevail over the equatorial Atlantic. Atmospheric dynamic model simulations suggest that Rossby waves generated over South America can propagate to and potentially influence weather patterns in the Northern Hemisphere (NH). However, observational evidence has been absent previously. Here we focus on southeastern South American (SESA) precipitation anomalies, which can characterize intraseasonal rainfall variability of the SAMS. Since tropical “westerly duct” and convective heating are important factors for cross‐equatorial propagation of Rossby wave (CEPRW), we identify two groups of events based on the two factors. By comparing the events associated with both SESA rainfall and tropical westerlies to the events associated with tropical westerlies only, we find that an anomalous Rossby wave train is triggered by precipitation anomalies over SESA, propagates in the southwest–northeast direction, and subsequently crosses the equator. Over a period of 4 days, near‐surface temperature over northwestern Africa and western Europe becomes warmer, accompanied by increased surface downward longwave radiation and precipitable water. The equatorward propagating Eliassen–Palm flux anomalies originated from SESA support the evidence of CEPRW. Simulations using a time‐dependent linear barotropic model forced by prescribed divergence anomalies over SESA further confirm that SESA rainfall can influence the NH weather patterns through CEPRW. Knowledge of this study will help us better understand and model interhemispheric teleconnections over the American–Atlantic–African/European sector.

Petrogenesis and geological implications of the qiyishan triassic granitoids in east Beishan orogen, inner Mongolia, NW China: evidence from geochronology, geochemistry and Nd-Hf isotopes

The Qiyishan deposit is a large-scale Rb polymetallic deposit in the Beishan orogen. However, there remain debates regarding its metallogenic age and tectonic setting. In addition, studies of Triassic tectono-magmatic events in the Beishan orogen are still insufficient, and conducting genesis studies on the Qiyishan Triassic granitoids will help to enhance the understanding of Triassic magmatism and tectonic evolution in the Beishan orogen. In this contribution, we report new data for the ore-forming granitoids of Qiyishan deposit, including zircon U-Pb ages, major and trace element concentrations and Nd-Hf isotope compositions to define the ages and genesis of the Qiyishan granitoids and discuss their origin and geodynamic implications. Zircon U-Pb dating of the Qiyishan ore-forming granitoids yielded three ages of 217.5 ± 1.3 Ma, 217.2 ±0.8 Ma, and 207.5 ± 2.0 Ma, respectively. The age of Rb mineralization can be constrained to 207.5± 2.0 Ma, while the age of W-Sn-Mo mineralization is considered to be slightly younger than approximately 217 Ma. The Characteristics of major and trace elements of the rock samples indicate that the Qiyishan granites can be classified to highly fractionated I-type granite, and characterised by a transition to A-type like granite to some extent. The granites were not only affected by fractional crystallisation, but also underwent magmatic-hydrothermal interaction. The zircon εHf(t) values of the Qiyishan granitoids ranged from 3.28 to 16.07 and the Hf model age (TDMc) ranged from 0.216 to 1.042 Ga, revealing that the Qiyishan granitoids originated from the partial melting of both mantle and crustal sources. εNd(t) values ranged from −0.52 to −0.25, with Nd model ages of 0.998 Ga to 1.007 Ga. These results indicate that the granitoids originated from the mantle-derived magmas intruding into the lower crust within an intracontinental extensional environment. Combining the previous studies of Triassic granites in the Beishan orogen and this work, the Triassic granites exhibit a transition from I-type to A-type along the northeast direction, indicating a decrease in the contribution of ancient crustal to the magma source. We propose that the Qiyishan granitoids formed in a transitional tectonic environment, signifying the shift from post-orogenic to intracontinental extensional settings in beishan orogen during late Triassic.

CONTENT OF HEAVY METALS IN THE SNOW COVER OF THE EASTERN INDUSTRIAL ZONE OF PAVLODAR

This article analyzes the content of heavy metals in the snow cover of the industrial areas of the city of Pavlodar, which made it possible to identify the presence of the problem of environmental pollution. Data on the content of various elements in snow by hazard class were analyzed: in the first hazard class, Zn has the highest content, on average 187.5 mg/kg, the greatest variation in the content of elements is observed in Cd – the coefficient of variation is 118.5%, a high concentration coefficient for Pb and Zn; in the second class – Cr has the highest content, on average 259.1 mg/kg, the greatest variation is observed in Cu – the coefficient of variation is 92%, the concentration coefficient is high in Cr; in the third class – Ba has the highest content, on average 777.5 mg/kg, the coefficient of variation and concentration of Mn. Studies have shown that the content of heavy metals in the snow increases in the northeast direction from the industrial enterprises of the eastern industrial zone of Pavlodar. According to calculations, the content of all heavy metals of the first hazard class in the snow exceeds the maximum permissible concentration (MPC) of soils. The content of cadmium exceeds the maximum permissible concentration by more than 17 times. Heavy metals of the second hazard class are in the range of 0.4–3.2 times the MPC. Strontium exceeds MPC by 25 times. The analysis carried out is an important step in understanding the ecological situation in Pavlodar and can be useful for taking measures to protect the environment and improve the ecological situation in this area.

Spatial Correlations of Regional Tropical Cyclone– and Nontropical Cyclone–Induced Severe Rainstorms during 2000–19

Abstract Severe rainstorms are one of the most devastating disasters in southeast China (SEC). A deep and comprehensive understanding of the spatial correlations of severe rainstorms is important for preventing rainstorm-induced hazards. In this study, tropical cyclone– and nontropical cyclone–induced severe rainstorms (TCSRs and NTCSRs, respectively) over SEC during 2000–19 are discussed. Co-occurrence probability and range values calculated using the semivariogram method are used to measure the spatial correlations of severe rainstorms. The extent to which potential factors [El Niño/La Niña, Indian Ocean dipole (IOD), latitudes, longitudes, temperature, elevation, and radius of maximum wind] affect the spatial structure of severe rainstorms is discussed. The spatial correlation distances for TCSRs (300–700 km) in typhoon season (July, August, and September) are longer than most of those for NTCSRs (150–300 km) in mei-yu season (June and July). The range values of TCSRs at each percentile (except for the minimum range values) tend to be omnidirectional. While NTCSRs tend to have a major direction of northeast–southwest. El Niño tends to increase the average spatial correlation distance of TCSRs in the northeast–southwest and NTCSRs in the north–northeast. La Niña tends to decrease the spatial correlation distance of TCSRs in the northeast–southwest. The occurrence of positive IOD (+IOD) and negative IOD (−IOD) events may increase the spatial correlation distance of TCSRs in the northwest–southeast, and −IOD events may decrease the distance in the northeast–southwest. IOD events, especially −IOD, may change the spatial correlation distance of NTCSRs in the east–northeast. Latitudes, longitudes, temperature, elevation, and radius of maximum wind significantly affect the spatial correlation distance of TCSRs in various directions. Significance Statement Spatial correlation distances of rainfall events, especially severe rainstorms induced by different weather systems such as tropical and nontropical cyclones (TCSR and NTCSR), can provide important information for rain-induced hazard risk mitigation. Moreover, factors that affect the variability of the spatial correlation distance of TCSRs and NTCSRs are also of interest. To this end, co-occurrence probability and semivariogram methods are used to obtain the spatial correlation distances. The spatial correlation distance of TCSRs varies between 300 and 700 km in typhoon season (July, August, and September) while it ranges between 150 and 300 km in mei-yu season (June and July) for NTCSRs over southeast China (SEC). El Niño/La Niña, Indian Ocean dipole (IOD), latitudes, longitudes, temperature, elevation, and radius of maximum wind have significant impacts on the spatial correlation distances of TCSRs. These findings can provide useful information for forecasting the spatial correlation distance of severe rainstorms over SEC.

A deep dive into the Type II Globular Cluster NGC 1851

Abstract About one-fifth of the Galactic globular clusters (GCs), dubbed Type II GCs, host distinct stellar populations with different heavy elements abundances. NGC 1851 is one of the most studied Type II GCs, surrounded by several controversies regarding the spatial distribution of its populations and the presence of star-to-star [Fe/H], C+N+O, and age differences. This paper provides a detailed characterization of its stellar populations through Hubble Space Telescope (HST), ground-based, and Gaia photometry. We identified two distinct populations with different abundances of s-process elements along the red-giant branch (RGB) and the sub-giant branch (SGB) and detected two sub-populations among both s-poor (canonical) and s-rich (anomalous) stars. To constrain the chemical composition of these stellar populations, we compared observed and simulated colors of stars with different abundances of He, C, N, and O. It results that the anomalous population has a higher CNO overall abundance compared to the canonical population and that both host stars with different light-element abundances. No significant differences in radial segregation between canonical and anomalous stars are detected, while we find that among their sub-populations, the two most chemical extremes are more centrally concentrated. Anomalous and canonical stars show different 2D spatial distributions outside ∼3 arcmin, with the latter developing an elliptical shape and a stellar overdensity in the northeast direction. We confirm the presence of a stellar halo up to ∼80 arcmin with Gaia photometry, tagging 14 and five of its stars as canonical and anomalous, respectively, finding a lack of the latter in the south/southeast field.

FEATURES OF RELIEF OF THE BORZHAVA RIVER MIDDLE FLOW AREA AND THEIR CONNECTION WITH GEODYNAMICS AND SEISMOTECTONICS

With attraction of the newest (until 2010–2022 inclusive) geological-geophysical and geodetic data and geological-tectonic construction, the features of relief of the Borzhava River middle flow area (Ukrainian Transcarpathians) were analyzed, including peculiarities of the morphology of the river valley, their connection with the geodynamics and seismotectonics of the territory is traced. In the interval between Keretsky and Dovge villages the river flows in the valley of south – southeast direction between the southwestern slopes of the Folded Carpathians and northeastern slopes of Vygorlat-Guta volcanic ridge, tracing the near-surface localization of Transcarpathian deep fault zone geological structures (fault-suture, i.e. contact zones of the tectonic structures of the Transcarpathian depression and the Folded Carpathians). In the Dovge village river terns to the southwest and crosses the Vygorlat-Guta ridge in this direction in the interval to the Velyki Komyaty village, its valley here is associated with rupture discontinuities of the diagonal Borzhava fault zone. The place of terns of the Borzhava River in the Dovge village is connected with the area of junction of the structures of the Borzhava fault zone and the Transcarpathian fault-suture zone. The Onok height and the Velykyy Sholles volcanic ridge, which surround it from the southeast and east, are connected with influence of the diagonal Vynohradiv and meridional Oash faults. In the northeastern parth of studied area, under the mountain ranges of the Kuk – Palenyy Grun` ridges, a relatively deep (40–55 km) zone of seismic activity was discovered, it is related to the area of junction of the deep tectonic structures of the Transcarpathian and Oash fault zones, the first of which dips in the northeast direction under the Carpathians, and the second (its tilted subfault) dips in the eastern direction under the structures of the Solotvyno depression. Also regular, including the newest (2 perceptible earthquakes since the beginning of 2023) seismic activity (mainly at the depths of the pre-Neogene basement (2–6 km)) is demonstrated in the studied area (along with fault-block structures of the Transcarpathian trough and fold-thrust structures of the Folded Carpathians) by the structures Borzhava fault zone (orthogonal to the Carpathians, mini-graben in structure) and conjugated with it, the more submeridional Shalanky-Irshava (slightly sigmoid in plan) and Petrovo-Ardanovo faults. The genesis of the specified peculiarities of the relief and seismicity of the studied area is analyzed from the point of view of a combination of "alpine" (thrust-subduction of the crustal structures of the Transcarpathian depression and sedimentary strata of the modern Folded Carpathians to the northeast – the so-called multi-tiered "crocodile" tectonics), present "terrain" (shift to the east of the crustal structures of the Transcarpathian depression – northeastern end of the Alkapa terrane – superimposed, relatively low-amplitude process) and "asthenolitic" ("spreading" of convective flows from the asthenolite under Pannonia) components of late Neogene ("post-magmatic", up to 5–7 million years ago) and modern regional geodynamic process. Key words: Ukrainian Transcarpathians; Borzhava River valley; cross section; channel slope; faults; geodynamics; earthquake; seismotectonics.

Сравнительная характеристика региональных сейсмогенерирующих структур Европейско-Африканского сквозного тектонического пояса

Based on new data on seismicity and materials from surveys of active faults, information was obtained on regional seismogenic structures of the European-African through tectonic belt. The kinematic characteristics of the faults that make up the through tectonic belt and earthquakes that occurred within these structures are given. An analysis of gravity anomalies based on satellite data suggests that the seismogenic structures of the European -African through tectonic belt have an ultra-deep penetration into the mantle, which determines their high seismic potential. This potential was manifested by catastrophic earthquakes in the Mediterranean-Caspian region on February 6, 2023. Afterthe earthquakes onFebruary 6, 2023,themigration ofseismic activity inthe northeast direction, inthe area ofthe Caucasus fold structure and the East European platform, was noted.

First Data on Vertical Particle Fluxes and Environmental Conditions in the Northern Segment of the Mohns Ridge, Norwegian Sea

Continuous two-year studies of particle fluxes and associated environmental parameters in the axial zone of the Arctic segment of the Mid-Atlantic Ridge at the junction of the Mohns and Knipovich ridges (Norwegian Sea) have been carried out for the first time. Sediment traps were deployed from the R/V Akademik Mstislav Keldysh in June 2019 in the northeastern part of the Mohns Ridge with revision in August 2020 and lifting in July 2021. It is shown that the sedimentation of particles in the study area was affected by the global transport of water masses in the northeasterly direction, with Atlantic waters in the subsurface layer and water masses of Arctic origin recirculating deeper in the subsurface. A weak positive temperature trend at a depth of more than 2500 m (0.02°C over two years) is detected. The bimodal vertical distribution of fluxes and changes in the composition of sinking particles corresponded to the pattern of sediment recycling in the ocean. The annual course of fluxes in the subsurface layer is determined by the activity of Si-concentrating and calcifying plankton, while the maximum bloom period is also manifested in the deep layer. At the same time, the main significant source of the flux deeper than 2000 m is the supply of lithogenic matter from the near-bottom nepheloid layer.

Arctic Sea Ice Melt Onset in the Laptev Sea and East Siberian Sea in Association with the Arctic Oscillation and Barents Oscillation

Abstract Arctic summer sea ice has been declining in recent decades. In this study, we investigate the beginning of the Arctic melting season, i.e., sea ice melt onset (MO), in the Laptev Sea (LS) and East Siberian Sea (ESS) along the Northern Sea route. Three leading modes are identified by EOF decomposition, which we call the LE-mode, L-mode, and E-mode. In positive phases these modes exhibit earlier MO in the two seas, a seesaw-like structure in the southwest–northeast direction with earlier MO in the LS, or in the southeast–northwest direction with earlier MO in the ESS. The LE-mode, L-mode, and E-mode are closely related to the Arctic Oscillation (AO) in April, the Barents Oscillation (BO) in April, and the AO in May, respectively. When the AO in April is positive, a low pressure anomaly northwest of the LS and ESS brings warm, moist air masses from the lower latitudes toward the LS and ESS and causes earlier MO, corresponding to the positive LE-mode. When the BO in April is negative, a cyclonic anomaly around the Barents Sea tends to warm and moisten the LS and cause earlier MO there, corresponding to the positive L-mode. When AO in May is positive, a low pressure anomaly northeast of the LS and ESS brings more warm, moist air toward the ESS and causes earlier MO there, corresponding to the positive E-mode. In the 1980s, the negative LE-mode was prominent whereas in the early 1990s the positive LE-mode was dominant. Since the mid-1990s, the L-mode and E-mode have appeared more frequently.