6 research outputs found

    Monitoring of Gamma Radiation Prior to Earthquakes at a Study of Lithosphere-Atmosphere-Ionosphere Coupling in Northern Tien Shan

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    Monitoring of radiation background in the near-surface atmosphere and of gamma rays, geoacoustic emission, and temperature in a borehole at 40m depth, as well as Doppler sounding on a low-inclined radio pass proceed at the Tien Shan mountain station (3340m a.s.l.) in Northern Tien Shan with common goal to search for seismogenic effects preceding earthquake. The flux of gamma rays in the borehole varies negligibly between the days, and it is not influenced by precipitations. Characteristic bay-like drops of the gamma ray flux were found (2-8)days before the M5.0-M6.2 earthquakes. In a M4.2 earthquake event with the 5.3km epicenter distance anomalies were detected (7-10)days before the earthquake in variation of the gamma ray flux, geoacoustic emission, and temperature. Simultaneously with gamma rays, a disturbance was detected in the Doppler shift of the ionospheric signal. Similarly, ionosphere disturbances triggered by the growth of radioactivity in the near-surface atmosphere were found at retrospective analysis of the Doppler shift data acquired after underground nuclear explosions at the Semipalatinsk testing site. This effect is considered from the viewpoint of the lithosphere-atmosphere-ionosphere coupling concept

    Behavior of galactic cosmic rays density and vector anisotropy before and during high-energy magnetospheric electron flux enhancements

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    Changes in the intensity of galactic cosmic rays on Earth and beyond the boundary of the magnetosphere occur earlier than an increase in the flux of high-energy magnetospheric electrons with energy >2 MeV in the geostationary orbit, so the behavior of galactic cosmic rays before and during electron flux enhancements can provide valuable information about the processes occurring in near-Earth space at this time. The density and vector anisotropy of galactic cosmic rays for 453 events of high-energy magnetospheric electron flux enhancements over the period 1996-2020 were calculated by the Global Survey Method (GSM). Some examples of these events, which are characteristic of different classes of solar sources, are considered. The behavior of the density and vector anisotropy of galactic cosmic rays before and during electron flux enhancements in events connected with the arrival to Earth of high-speed streams from coronal holes, coronal mass ejections associated with solar flares or disappeared solar filaments is revealed

    Disturbances of Doppler Frequency Shift of Ionospheric Signal and of Telluric Current Caused by Atmospheric Waves from Explosive Eruption of Hunga Tonga Volcano on January 15, 2022

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    After the explosive eruption of the Hunga Tonga volcano on January 15, 2022, disturbances were observed at a distance of about 12,000 km in Northern Tien Shan and regarded variations in the atmospheric pressure, in telluric current, and in the Doppler frequency shift of ionospheric signal. At 16:00:55 UTC, a pulse of atmospheric pressure was detected there, with peak amplitude of 1.3 hPa and propagation speed of 0.3056 km/s, equal to the velocity of Lamb waves. In the variations in the Doppler frequency shift, disturbances of two types were registered on the 3212 km and 2969 km long inclined radio paths, one of which arose as a response to the passage of a Lamb wave (0.3059 km/s) through the reflection point of the radio wave and another as reaction to an acoustic-gravity wave (0.2602 km/s). Two successive perturbations were also detected in the records of telluric current at the arrival times of the Lamb and acoustic-gravity waves at the registration point. According to the parameters of the Lamb wave, the energy transfer into the atmosphere upon the explosion of the Hunga Tonga volcano was roughly estimated to be 2000 Mt of TNT equivalent

    Predicting and detecting fires on multispectral images using machine learning methods

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    In today's world, fire forecasting and early detection play a critical role in preventing disasters and minimizing damage to the environment and human settlements. The main goal of the study is the development and testing of machine learning algorithms for automated detection of the initial stages of fires based on the analysis of multispectral images. Within the framework of this study, the capabilities of three popular machine learning methods: extreme gradient boosting, logistic regression, and vanilla convolutional neural network (vanilla CNN), are considered in the task of processing and interpreting multispectral images to predict and detect fires. XGBoost, as a gradient-boosted decision tree algorithm, provides high processing speed and accuracy, logistic regression stands out for its simplicity and interpretability, while vanilla CNN uses the power of deep learning to analyze spatial and spectral data. The results of the study show that the integration of these methods into monitoring systems can significantly improve the efficiency of early fire detection, as well as help in predicting potential fires

    The First Inventory of Rock Glaciers in the Zhetysu Alatau: The Aksu and Lepsy River Basins

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    While rock glaciers (RGs) are widespread in the Zhetysu Alatau mountain range of Tien Shan (Kazakhstan), they have not yet been systematically investigated. In this study, we present the first rock glacier inventory of this region containing 256 rock glaciers with quantitative information about their locations, geomorphic parameters, and downslope velocities, as established using a method that combines SAR interferometry and optical images from Google Earth. Our inventory shows that most of the RGs are talus-derived (61%). The maximum downslope velocity of the active rock glaciers (ARGs) was 252 mm yr−1. The average lower height of rock glaciers in this part of the Zhetysu Alatau was 3036 m above sea level (ASL). The largest area of rock glaciers was located between 2800 and 3400 m ASL and covered almost 86% of the total area. Most rock glaciers had a northern (northern, northeastern, and northwestern) orientation, which indicated the important role of solar insolation in their formation and preservation

    Accelerated Glacier Area Loss in the Zhetysu (Dzhungar) Alatau Range (Tien Shan) for the Period of 1956–2016

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    An updated glacier inventory is important for understanding the current glacier dynamics in the conditions of actual accelerating glacier retreat observed around the world. Here, we present a detailed analysis of the glaciation areas of the Zhetysu Alatau Range (Tien Shan) for 1956–2016 using well-established semiautomatic methods based on the band ratios. The total glacier area decreased by 49 ± 2.8% or by 399 ± 11.2 km2 from 813.6 ± 22.8 km2 to 414.6 ± 11.6 km2 during 1956–2016, while the number of glaciers increased from 985 to 813. Similar rates of area change characterized the periods 1956–2001, 2001–2012, 2012–2016, and 2001–2016: −296.2 ± 8.3 (−0.8% a−1), −63.7± 1.8 (−1.1% a−1), −39.1 ±1.1 (−2.2% a−1) and −102.8 ± 2.9 (−1.3% a−1) km2, respectively. The mean glacier size decreased from 0.57 km2 in 2001 to 0.51 km2 in 2016. Most glaciation areas of the Zhetysu Alatau faced north (north, northwest, and northeast), covered 390.35 ± 11 km2, and were located in altitudes between 3000 and 4000 m.a.s.l. With shrinkage rates of about −0.8% and −1.3% a−1 for the periods of 1956–2001 and 2001–2016, our results show that study area has the highest shrinkage rate compared to other glacierized areas of Central Asian mountains, including Altai, Pamir, and even the inner ranges of Tien Shan. It was found that a significant increase in temperature (0.12 °C/10 years) plays a main role in the state of glaciers
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