ПРОВЕДЕНИЕ ДЕТАЛЬНЫХ АЭРОГЕОФИЗИЧЕСКИХ РАБОТ В СЛОЖНОДИСЛОЦИРОВАННЫХ КОМПЛЕКСАХ СУТАМСКОГО ТЕРРЕЙНА (АЛДАНСКИЙ ЩИТ) ПРИ ИЗУЧЕНИИ ЖЕЛЕЗОРУДНЫХ МЕСТОРОЖДЕНИЙ

Magnetic exploration is the most informational and economical method of prospecting and exploration of iron-ore deposits. In rough-terrain and remote areas without any infrastructure, problems associated with ground-based methods can be avoided by using modern unmanned technologies that allow conducting geophysical surveys in a more efficient way. An unmanned aeromagnetic survey complex (aerial vehicle, UAV) Geoscan 401 was used to assess the possibility of using UAVs for aeromagnetic surveying of iron-ore deposits. Our experimental study was conducted in the well-studied area of the largest iron-ore deposit of South Yakutia. The UAV capacities were confirmed by comparing the aeromagnetic survey data with the available data obtained by ground magnetic exploration of the study area. By analysing magnetic fields, we established that the anomalies detected by the ground and aeromagnetic surveys were fully identical. Furthermore, a weak anomaly was discovered in the northeastern part of the study area (it was not reflected in the magnetic field from the ground survey data). Recalculation of the vertical gradient of the magnetic field shows that the anomaly is caused by a blind ore body. Its upper edge is located at a depth of 200–250 m from the day surface. In calculations for a data array without gradient intervals, a mean square error (MSE) amounts to 1.01 nT. An absolute error in the heights of the working and control flights did not exceed 1.5 m. Both the preliminary and control measurements were performed very efficiently. Profiles for UAV surveys were spaced by 100 m. A 1.0 km2 site was covered by one flight within approximately 20 minutes. The Geoskan-401 UAV is useful for obtaining orthophotos, topographic maps and 3D models of the surveyed territory as required for further studies consistent with the magnetic surveys. The aeromagnetic surveys were followed by trenching to verify the newly discovered anomalies. Based on the results of this experimental study, the forecast resources of the Sutam deposit should be increased by almost 250–350 million tons, i.e. plus 15 % to the previously explored and approved reserves of the Sutam field.Магниторазведка представляет собой наиболее информационный и экономичный метод при поиске и разведке железорудных месторождений. Избежать проблем с постановкой наземных методов на труднопроходимых и удаленных от инфраструктуры территориях, повысить скорость их изучения позволяют беспилотные технологии. Для оценки возможности применения беспилотной аэромагнитной съемки на железорудных объектах Якутии были выполнены опытно-методические работы на уже хорошо изученном ранее крупнейшем железорудном месторождении Южной Якутии с использованием беспилотного комплекса «Геоскан 401». Данный подход позволил установить работоспособность полетного комплекса, сопоставив имеющиеся данные наземных магниторазведочных работ с данными аэромагниторазведочных работ. Анализ магнитных полей показал полную идентичность полученных аномалий наземной и аэромагнитной съемки. Более того, на северо-востоке участка была выделена слабая аномалия, которая не отражена в магнитном поле наземной съемки. Пересчет вертикального градиента магнитного поля позволил определить, что аномалия обусловлена слепым рудным телом, верхняя кромка которого располагается на глубине 200–250 м от дневной поверхности. Среднеквадратическая погрешность, вычисленная для массива данных без градиентных интервалов, составила 1.01 нТл. Абсолютная погрешность высоты основного и контрольного полетов не превышает 1.5 м. По результатам рабочих и контрольных замеров отмечается высокая воспроизводимость измерений. За один полет по сети профилей с шагом 100 м был изучен участок площадью 1 км2. Полетное время составило немногим более 20 мин. Дополнением работы с полетным комплексом «Геоскан-401» стала возможность съемки ортофотопланов, топопланов, трехмерных моделей местности – в зависимости от потребностей – последовательно с выполнением магниторазведочных работ. Согласно результатам аэромагниторазведочных работ и последующей заверки полученных новых аномалий горно-вскрышными работами в виде канав и траншей, прирост прогнозных ресурсов Сутамской площади составил примерно 250–350 млн т – 15 % от уже опоискованных ранее и утвержденных запасов Сутамского месторождения

ГЕОДИНАМИЧЕСКАЯ АКТИВНОСТЬ НОВЕЙШИХ СТРУКТУР И ПОЛЯ ТЕКТОНИЧЕСКИХ НАПРЯЖЕНИЙ СЕВЕРО-ВОСТОКА АЗИИ

Based on the analysis of changes in the stress-strain state of the crust at the boundary of the Eurasian and North American tectonic plates, we develop a dynamic model of the main seismogenerating structures inNortheast Asia. We have established a regularity in changes of geodynamic regimes within the interplate boundary between the Kolyma-Chukotka crustal plate and the Eurasian, North American and Pacific tectonic plates: spreading in the Gakkel Ridge area; rifting in the Laptev Sea shelf; a mixture of tectonic stress types in the Kharaulakh segment; transpression in the Chersky seismotectonic zone, in the segment from the Komandor to the Aleutian Islands, and in the Koryak segment; and crustal stretching in the Chukotka segment.Анализ изменений напряженно-деформированного состояния земной коры, проведенный вдоль границы Евразийской и Североамериканской литосферных плит, позволил обосновать динамическую модель главных сейсмогенерирующих структур территории северо-востока Азии. В пределах единой межплитной границы, отделяющей Колымо-Чукотскую коровую плиту от Евразийской, Североамериканской и Тихоокеанской литосферных плит, наблюдается закономерная смена геодинамических режимов: спрединг хребта Гаккеля; рифтогенез на шельфе моря Лаптевых; смешанное поле тектонических напряжений в Хараулахском сегменте; транспрессия в сейсмотектонической зоне Черского, на участке от Командорских до Алеутских островов и в Корякском сегменте; растяжение в Чукотском сегменте

Myocardial infarction in the population of some Russian regions and its prognostic value

Aim. To study the prevalence of myocardial infarction (MI) in the population of Russian regions and its contribution to cardiovascular events.Material and methods. The analysis material was representative samples of the population aged 35-64 years from 11 Russian regions,  examined within the multicenter study “Epidemiology of Cardiovascular Diseases and their Risk Factors in Regions  of Russian Federation”. The response rate was about 80%. The study used a community-based  systematic stratified multiply random sample. During the study, information on prior MI was obtained using a standard questionnaire. Anthropometry and measurement of blood pressure (BP) and heart rate (HR) with an automatic BP monitor were performed. Resting electrocardiography (ECG) was performed, followed by Minnesota coding. Major and minor QQS waves and STT segments were considered as ischemic  ECG abnormalities. Biochemical parameters were determined using an Arkhitect 000 Clinical Chemistry Analyzer. The median prospective  follow-up was 6,21 [5,25; 6,75] years. A composite endpoint (CE) was analyzed, including cardiovascular death and non-fatal MI. During the follow-up period, 363 all-cause deaths were detected,  of which 134 were from cardiovascular diseases, while 196 — CEs. Statistical analysis was carried out in R 3.6.1 environment.Results. The MI prevalence among the Russian population was 2,9%; 5,2% for men and 1,5% for women,  increasing  with age. Men with prior MI were  more likely to take statins and beta-blockers  than women as follows: 39,0% vs 25,6% and 29,3% vs 27,1%, respectively. MI newly diagnosed within the follow-up  period was associated with the following risk factors (RFs): smoking, increased BP, HR, triglycerides and glucose.  For individuals with prior MI, a significant relationship was found only with smoking.  Multiple comparison  of the contribution of RFs, ECG abnormalities,  and prior MI showed  that the inclusion of ischemic ECG abnormalities in the analysis significantly increases  the risk of cardiovascular events in individuals without prior MI compared with individuals without both MI and ECG changes.  A high CE risk was noted in patients with prior MI: relative risk (RR), 4,73 (2,92-7,65); the addition of ischemic ECG abnormalities increased the RR to 5,75 (3,76-8,8).Conclusion. The RR of CEs in patients  with prior MI without or with ischemic ECG changes  is 4,73 and 5,75 times higher than in patients without MI and ECG abnormalities. The risk factors  identified  in this case cannot explain such an increase  in CEs. It is obvious  that people  with prior MI need  rehabilitation. The presence of RFs in patients with newly diagnosed  MI indicates insufficient primary prevention, which suggests  that strengthening preventive measures to eliminate conventional risk factors in patients with newly diagnosed  MI will help reduce the risk of recurrent MI or cardiovascular  mortality

Non-High Density Lipoprotein Cholesterol: A Modern Benchmark for Assessing Lipid Metabolism Disorders

Aim. To perform a population analysis of Non-High Density Lipoprotein Cholesterol level (non-HDL-c) in Russian population and to evaluate its association with cardiovascular events.Material and Methods. The material consisted of results obtained from 11 regions of the ESSE-RF1 Study and from 4 regions of the ESSE-RF2 Study. Study protocols were identical. The studies were performed in 2012-2014 and 2017, respectively. Endpoints were assessed in 19041 people aged 35-64 years. The median follow-up was 6.5 years in ESSE RF (1) and 3.8 years in ESSE RF(2). Analysis was performed for three lipid variables: total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and non-HDLC in two samples: the general population sample and the same sample without individuals with coronary heart disease (CHD), myocardial infarction (MI) and/or stroke history and not taking statins (the population sample of "without a history of cardiovascular diseases [CVD]". The analysis of nonlinear associations was performed using the generalized additive Cox model. The combined cardiovascular endpoint was represented by cardiovascular death and nonfatal MI and stroke. Traditional and laboratory FRs, socio-demographic parameters were analyzed. The significance level for all tested hypotheses was set to be 0.05.Results. The prevalence of elevated non-HDL-C level (>3.7 mmol/l) was found to be 74.6%. No gender differences were found: there was 74.6% for men and 74.5% for women. Both mean values and prevalence of elevated non-HDL-C were increased with age in women, and its level was slightly decreased in men after 55 years old. Almost all analyzed RFs were significantly associated with elevated non-HDL-C in these two population samples. In both samples elevated total CH and elevated LDL-C were associated with all-cause mortality after correction for all RFs. On the contrary, the non-HDL-C was associated with CVD combined end pints. It has been shown that the risk of these end points increases uniformly with increase in levels of non HDL cholesterol, no nonlinear associations were found.Conclusion. The results of a population-based analysis of non-HDL-C performed in the Russian population for the first time confirmed that elevated non-HDL-C levels contribute significantly to determining the risk of cardiovascular events in the medium term. It can be assumed that the new risk scales (SCORE2 and SCORE OP) proposed by the European Society of Cardiology and the European Society of Preventive Cardiology, which include non-HDL C instead of TC, will allow adequate assessment of 10-year cardiovascular risk for Russians. However, continued monitoring of endpoints in order to obtain stable associations is required

Seismogeodynamics of interaction area of the Baikal rift northeastern flank and Aldan-Stanovoy block

The article presents modern structural-tectonic plan and tectonic-dynamic model of the zone of interaction of the most seismicity active northeastern part of the Baikal rift zone (BRZ) and the adjoint system seismogenic structures of the Aldan-Stanovoy block in southern Yakutia, where is marked a series of seismic disasters with magnitude M ≥ 6. The patterns of structure formation and kinematic types of adjoint active faults, which form structural blocks, where accumulate considerable tectonic stress are discussed. The interaction between large tectonic blocks causes a sudden release of stresses, which results in catastrophic earthquakes (M ≥ 6.0) with focal mechanisms of definite kinematic type

DETAILED AIRBORNE GEOPHYSICAL SURVEY OF COMPLEXLY DISLOCATED STRATA IN THE SUTAM TERRANE (ALDAN SHIELD) DURING STUDIES OF IRON-ORE DEPOSITS

Magnetic exploration is the most informational and economical method of prospecting and exploration of iron-ore deposits. In rough-terrain and remote areas without any infrastructure, problems associated with ground-based methods can be avoided by using modern unmanned technologies that allow conducting geophysical surveys in a more efficient way. An unmanned aeromagnetic survey complex (aerial vehicle, UAV) Geoscan 401 was used to assess the possibility of using UAVs for aeromagnetic surveying of iron-ore deposits. Our experimental study was conducted in the well-studied area of the largest iron-ore deposit of South Yakutia. The UAV capacities were confirmed by comparing the aeromagnetic survey data with the available data obtained by ground magnetic exploration of the study area. By analysing magnetic fields, we established that the anomalies detected by the ground and aeromagnetic surveys were fully identical. Furthermore, a weak anomaly was discovered in the northeastern part of the study area (it was not reflected in the magnetic field from the ground survey data). Recalculation of the vertical gradient of the magnetic field shows that the anomaly is caused by a blind ore body. Its upper edge is located at a depth of 200–250 m from the day surface. In calculations for a data array without gradient intervals, a mean square error (MSE) amounts to 1.01 nT. An absolute error in the heights of the working and control flights did not exceed 1.5 m. Both the preliminary and control measurements were performed very efficiently. Profiles for UAV surveys were spaced by 100 m. A 1.0 km2 site was covered by one flight within approximately 20 minutes. The Geoskan-401 UAV is useful for obtaining orthophotos, topographic maps and 3D models of the surveyed territory as required for further studies consistent with the magnetic surveys. The aeromagnetic surveys were followed by trenching to verify the newly discovered anomalies. Based on the results of this experimental study, the forecast resources of the Sutam deposit should be increased by almost 250–350 million tons, i.e. plus 15 % to the previously explored and approved reserves of the Sutam field

GEODYNAMIC ACTIVITY OF MODERN STRUCTURES AND TECTONIC STRESS FIELDS IN NORTHEAST ASIA

Based on the analysis of changes in the stress-strain state of the crust at the boundary of the Eurasian and North American tectonic plates, we develop a dynamic model of the main seismogenerating structures inNortheast Asia. We have established a regularity in changes of geodynamic regimes within the interplate boundary between the Kolyma-Chukotka crustal plate and the Eurasian, North American and Pacific tectonic plates: spreading in the Gakkel Ridge area; rifting in the Laptev Sea shelf; a mixture of tectonic stress types in the Kharaulakh segment; transpression in the Chersky seismotectonic zone, in the segment from the Komandor to the Aleutian Islands, and in the Koryak segment; and crustal stretching in the Chukotka segment