Geophysical Institute Research Articles

The 4m International Liquid Mirror Telescope Project

The International Liquid Mirror Telescope (ILMT) project is a scientific collaboration in observational astrophysics between the Liège Institute of Astrophysics and Geophysics (Liège University, Belgium), the Aryabatta Research Institute of observational sciencES (ARIES, Nainital, India) and several Canadian universities (British Columbia, Laval, Montréal, Toronto, Victoria and York). Meanwhile, several other institutes have joined the project: the Royal Observatory of Belgium, the National University of Uzbekistan and the Ulugh Beg Astronomical Institute (Uzbekistan) as well as the Poznan Observatory (Poland). The Liège company AMOS (Advanced Mechanical and Optical Systems) has built the telescope structure that has been erected on the ARIES site in Devasthal (Uttarakhand, India). It is the first liquid mirror telescope being dedicated to astronomical observations. First light was obtained on 29th April 2022 and commissioning is being conducted at the present time. In this short article, we describe and illustrate the main components of the ILMT. We also highlight the ILMT papers presented during the third BINA workshop, which discuss various aspects of the ILMT science programs.

Anomalous geoobjects in the Lithosphere of Uzbekistan and their interrelations with ore deposits

One of the priority tasks of the Geological Service of the Republic of Uzbekistan is the study of the paleozoic foundation under the cover of Meso-Cenozoic sediments, mainly using deep seismic sounding profiles, in order to trace known ore fields and mineralized zones in the overlying part of the basement. In recent years, in the laboratory “Structure of the Lithosphere” of the Institute of Geology and Geophysics named after Kh.M. Abdullayev, new data have been obtained as a result of reinterpretation of a complex of geophysical data. In the present work examines the role of anomalous geoobjects with high and low seismic density parameters along deep seismic sounding (DSS) profiles in the Lithosphere of Uzbekistan from the point of view of their spatial correlation with explored deposits of ore minerals. New regional features of the interrelationships between the geological structure of the lithospheric deep structures of Uzbekistan and the spatial distribution of deposits have been identified.

ГЕОДИНАМІЧНИЙ СТАН ЗАКАРПАТСЬКОГО ВНУТРІШНЬОГО ПРОГИНУ ЗА РЕЗУЛЬТАТАМИ ДЕФОРМОМЕТРИЧНИХ СПОСТЕРЕЖЕНЬ У РЕГІОНІ

Background. The relevance of the research is determined by the gradual increase in local seismicity in the region, which occupies a peculiar geographical location, through which oil, gas and product pipelines pass, and in which critical infrastructure facilities are located that may be affected by the underground natural disaster. It is important to have information on the movements of the upper layers of the Earth's crust, their kinematics and dynamics, which significantly affect the stress-strain state of rocks and the release of energy from geomechanic processes. It is also necessary to investigate the influence of the region's geodynamics on the discharge of the stress-strain state of rocks. Methods. The research methodology is to construct time-dependent crustal displacements and compare velocities and accelerations of crustal movements in the intervals of anomalous modern lateral movements of the Earth's crust. The velocities and accelerations of crustal movements are calculated, the kinematics of movements and seismicity of the region are compared. Correlation analysis of the observed series is applied. To solve the tasks, we used the results of observations of horizontal crustal movements in the Oașh deep-seated fault area using a quartz strain gauge with a base of 24.5 m mounted in the adit of the Korolevo urban-type settlement. The seismic data were obtained using digital seismometers operating at the monitoring geophysical station of the Seismicity Department of the Carpathian region of S.I. Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine. Results. The article discusses the geodynamics of the Transcarpathian Inner Trough based on observations of modern lateral movements of the Earth's crust in the Oașh deep-seated fault area, which in 2021 were represented by rock extensions of +12.61x10-7. The physical parameters of geomotion in the region were calculated, the spatiotemporal distribution of local seismicity was established, and the relationship between seismic and geodynamic states in Transcarpathia in 2021 was studied. The variations of displacements of the upper layers of the Earth's crust over the entire period of deformation monitoring observations in Korolevo urban-type settlement (1999–2021) and the temporal distribution of local underground shocks were studied. Conclusions. The analysis of the spatio-temporal distribution of local seismicity and modern lateral movements of the Earth's crust over the entire period of deformation monitoring observations in the Oașh deep-seated fault area has indicated an increase in the seismicity of the region in the intervals of intense crustal movements and the presence of periods of crustal movement fluctuations for 12 years: familiar variable processes (expansion and contraction of rocks, the total magnitude of displacement fluctuations in the region of zero movements) were detected for 2–3 years. The most relevant and important are the periods of 9–10 years following these calm intervals, since during this time earthquakes are recorded and their frequency is also found to be increasing. The intensification of seismicity in the region is observed against the background of general rock extension, which occurs due to the steady age-related crustal movements. At the present stage, the current crustal movements are in a state of rock expansion, and if this trend does not change, an increase in seismicity in the region should be expected.

The correctness of the finite-difference problems of the time- and wave fields continuation for the migration image of the basement boundary

In modern seismic exploration, the migration procedure plays an important role for further interpretation of the observed data. It is the migration that makes it possible to display the deep structure of the geological section based on the dynamic characteristics of the registered wave fields.
 When processing WARRP (wide angle reflection/refraction profiling) seismic data, standard migration methods are ineffective, which is due to the peculiarities of observation systems. All existing migration methods are mainly based on reflected waves, which have a limited registration interval. The wave field on WARRP is observed at distances from sources that reach several hundred kilometers, and the uneven step between receivers is on average 1—3 km. Under such conditions, it is difficult and sometimes impossible to separate the reflected waves.
 The finite-difference reflection/refraction migration developed at the Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine has proven its effectiveness in constructing migration images of the depth structure of the section based on WARRP data observed in various regions of the world. The main difference of this migration method is the use of refracted waves as reference waves registered in the large offsets. At the same time, there is a question of the correctness of the reproduction of the depth structure of the section on the migration image, which depends on the correctness of the calculation methods. The algorithm of finite-difference reflection/refraction migration contains a continuation of the time and wave fields.
 The article presents a proof of the mathematical correctness of the solution of the eikonal differential equations and the scalar wave equation by the finite-difference method, on which are based the continuation of the time and wave fields, respectively.
 The given comparison of the formed migration images and the velocity models, calculated by the ray-tracing method, of the upper crust along the PANCAKE and TTZ-South profiles allows us to assert that the combination of the results of kinematic and dynamic processing of WARRP data allows to increase the informativeness of their further interpretation

International Scientific Conference "Geophysical Processes in the Earth and its Envelopes" (Chronicle)

Information about the international scientific conference "Geophysical Processes in the Earth and its Envelopes" Dedicated to 90-th Anniversary of Mikheil Nodia Institute of Geophysics of Ivane Javakhishvili Tbilisi State University, which was held on November 16-17, 2023 at Ivane Javakhishvili Tbilisi State University is presented.

Earth Observation Capacity of the National Geoinformation Center of Bulgaria as Part of the Tools for Geo- and Anthropogenic-Hazard Management in EPOS

Exploring the nature of the Earth system and its multi-scale architecture requires an integrated symbiotic approach not only to understand our planet but also to reveal the hazards and footprints of their events on human life. Following the conceptual model of the European Plate Observing System (EPOS) we integrate a variety of research to obtain a multilateral use of geoinformation for scientific and practical purposes. In 2018, we started building a Bulgarian distributed scientific infrastructure called the National Geoinformation Center, aiming to provide data, products, and expertise to predict and prevent natural and anthropogenic risks and disasters, as well as environmental changes. The present paper demonstrates the capabilities of seismological, Global Navigation Satellite System (GNSS), geomagnetic and multi-scale laboratories (MSL) in Bulgaria that participate to the respective thematic core services of EPOS. More than 40 seismological stations register and transmit data in real time through the operational center of the Bulgarian Seismological Network. Data from 18 GNSS stations, part of the National GNSS network, are officially registered in the EPOS GNSS Data Gateway. Data and products are available via the EPOS GNSS Product Portal for interested users. Panagjurishte geomagnetic observatory (PAG) provides real time variations and long-period data series for the Earth’s magnetic field. The Palaeomagnetic Laboratory at the National Institute of Geophysics, Geodesy and Geography (NIGGG) participates in MSL with its unique facilities for paleo-, archeo- and environmental magnetism studies. Four case studies are presented to illustrate best practices for utilizing the data collected. The analysis of seismicity in a region of a long-time exploited salt deposit is upgraded with GNSS data to reveal the reason for crustal movements in the region. The results show that the majority of the seismic events took place in the upper part of the Earth’s crust at a depth of up to 5 km, where the salt body is buried. The observed significant local deformations of the Earth’s surface are very likely related to the technological process of deposit exploitation. A recent model of the geomagnetic declination over the Bulgarian territory is also presented. It tracks the variation of the regional magnetic field from 2015 to 2020 and adds short-wavelength signals from the secular network observations. Last but not least, the application of a mineral magnetic laboratory analysis along the depth of a Holocene soil profile is demonstrated. Results reveal the soil evolution in response to environmental changes adding a new magnetic proxy parameter for more precise identification and characterization of the soil formation processes.

SEISMICITY of the CARPATHIANS in 2018–2019

The article describes seismic observations in the Carpathian region in 2018–2019, which were carried out, as before, by two organizations from two states: in Ukraine – the Seismicity department of the Carpathian region of the Institute of Geophysics of the National Academy of Sciences of Ukraine, in Moldova – the seismology laboratory of the Institute of Geology and Seismology of the Academy of Sciences of Moldova. The monitoring of seismicity was carried out 21 stationary digital and 3 temporary stations of Ukraine with a processing centre in Lviv and six stations of Moldova with a processing centre in Chisinau. The consolidated catalog of earthquakes was created in Lviv. The total number of Carpathian earthquakes in 2018–2019 was NΣ=99 in the range KR=4.5–13.6 within the interval of hypocenter depths h=0.4–157.5 km, with total seismic energy ΣE=4.2·1013 J. The maximum earthquake with KR=13.6, MSH=5.3 and hрР=150.6 km was registered on October 28, 2018 in the Vrancea zone. The epicentral zone was subjected to shaking with an intensity up to Ii=V by MM (Mercally) scale. The earthquake was felt by the population of Romania, Bulgaria, Ukraine, Moldova and other European countries. In the Precarpathian and Transcarpathian regions, all earthquakes were weaker. For Transcarpathia, their energy class was in the range of KR=5.5–7.9, and the depths was in the range of h=0.6–8.0 km. The strongest event in Precarpathian was a tangible earthquake that occurred in the Drohobych district of the Lviv region on September 27, 2018 with KR=7.3 at a depth of 1.7±0.9 km. The strongest event in Bukovina was an earthquake of March 24, 2018 with KR=9.4, МSH=2.4 and h=1 km near Novodnestrovsk city, Ukraina, which was felt by the population of the village of Lomachintsy with an intensity of 4 points. In Novodnestrovsk, the earthquake was felt only on the upper floors. In general, in 2018–2019 there was a slight decrease in the level of seismicity in seismically active areas: № 1 (North-Western), № 2 (Vrancea), № 5 (Bukovina) and № 8 (Bacau), compared with that in the previous period 2016–2017. In areas № 3 (South Carpathians), № 4 (Banat) and № 7 (Transylvania) there was no earthquakes, and in area № 6 (Krishana) only there was one earthquake with КР=10.8, MSH=3.2.

A Brief Overview of Joint Research of Vakhushti Bagrationi Institute of Geography M. Nodia Institute of Geophysics, and Georgian Technical University, Institute of Hydrometeorology over the Past 10 Years

A Brief Overview of Joint Research of Vakhushti Bagrationi Institute of Geography M. Nodia Institute of Geophysics, and Georgian Technical University, Institute of Hydrometeorology over the Past 10 Years

Global Seismic Networks Operated by the U.S. Geological Survey

Abstract The U.S. Geological Survey (USGS) Global Seismographic Network (GSN) Program operates two thirds of the GSN, a network of state-of-the-art, digital seismological and geophysical sensors with digital telecommunications. This network serves as a multiuse scientific facility and a valuable resource for research, education, and monitoring. The other one third of the GSN is funded by the National Science Foundation (NSF), and the operations of this component are overseen by EarthScope. This collaboration between the USGS, EarthScope, and NSF has allowed for the development and operations of the GSN to be a truly multiuse network that provides near real-time open access data, facilitating fundamental discoveries by the Earth science community, supporting the earthquake hazards mission of the USGS, benefitting tsunami monitoring by the National Oceanic and Atmospheric Administration, and contributing to nuclear test monitoring and treaty verification. In this article, we describe the installation and evolution of the seismic networks operated by the USGS that ultimately led to the USGS portion of the GSN (100 stations under network codes IU, IC, and CU) as they are today and envision technological advances and opportunities to further improve the utility of the network in the future. This article focuses on the USGS-operated component of the GSN; a companion article on the GSN stations funded by the NSF and operated by the Cecil and Ida Green Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California at San Diego by Davis et al. (2023) appears in this volume.

Homogenizing instrumental earthquake catalogs – a case study around the Dead Sea Transform Fault Zone

The creation of a homogenized earthquake catalog is a fundamental step in seismic hazard analysis. The homogenization procedure, however, is complex and requires a good understanding of the heterogeneities among the available bulletins. Common events within the bulletins have to be identified and assigned with the most suitable origin time and location solution, while all the events have to be harmonized into a single magnitude scale. This process entails several decision variables that are usually defined using qualitative measures or expert opinion, without a clear exploration of the associated uncertainties. To address this issue, we present an automated and data-driven workflow that defines spatio-temporal margins within which duplicate events fall and converts the various reported magnitudes into a common scale. Special attention has been paid to the fitted functional form and the validity range of the derived magnitude conversion relations. The proposed methodology has been successfully applied to a wide region around the Dead Sea Transform Fault Zone (27N-36N, 31E-39E), with input data from various sources such as the International Seismological Centre and the Geophysical Institute of Israel. The produced public catalog contains more than 5500 events, between 1900 and 2017, with moment magnitude Mw above 3. The MATLAB/Python scripts used in this study are also available.

Features of the Structure of the Winter Morning High- and Mid-Latitude Ionosphere

The structure of the winter morning (0500–0900 LT) ionosphere in the Northern and Southern hemispheres is studied in detail. For this, CHAMP satellite data for quiet conditions during the period of high solar activity of 2000–2002 are used. Careful analysis is used to identify electron concentration troughs: the high-latitude ionospheric trough; subauroral, or main, ionospheric trough; and mid-latitude ring ionospheric trough. In order to identify and separate the high-latitude and main ionospheric troughs, the model of auroral diffuse precipitation of the Polar Geophysical Institute is used, which describes the boundaries of low-latitude zone I and high-latitude zone II of auroral diffuse precipitation. The longitudinal variations of the precipitation boundaries are corrected using the DMSP satellite data. The problem of separating the troughs becomes more complicated with the passage of local time, because the main ionospheric trough is more strongly displaced to the pole than the auroral oval; therefore, its area of existence begins to overlap the area of existence of the high-latitude trough. In order to identify and separate the main and ring troughs, all, even weak, geomagnetic disturbances for the observation period are analyzed in detail. The asymmetry of the Northern and Southern hemispheres is considered, and similar and different characteristics are identified. Therefore, a more complete and accurate pattern of the structure of the morning ionosphere is obtained.

Manifestations of catastrophic Turkish earthquakes February 6, 2023 in Kryvbas

We analyzed the impact of powerful Turkish earthquakes that occurred on February 6, 2023, including a magnitude 7.8 Mw earthquake at 01:17:36 (UTC) in Kahramanmarash—Gaziantep, a magnitude 6.7/6.3 Mw earthquake at 01:28:21 (UTC), and a magnitude 7.5 Mw earthquake at 10:24:50 in Ekinoz—Kahramanmarash, on the territory of Ukraine, particularly in the city of Kryvyi Rih.The study involved the examination of algorithms for processing data recorded at seismic stations belonging to the S.I. Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine and the Main Center for Special Control of t he State Space Agency of Ukraine. The analysis of digital records from these Turkish earthquakes provided ground shaking intensity parameters at the recording points: Odesa and KryvyiRih had intensity levels below 3, Kremenchuk recorded 2, and Poltava and Kyiv registered 1. The resulting isoseismal map illustrates that the attenuation of wave intensity from the Turkish earthquakes depended on the geotectonic structure of the Ukrainian territory through which the seismic vibrations propagated.
 The monitoring of the water level in a deep well recorded changes in geodynamic (hydrodeformation) processes following the powerful Turkish earthquakes on February 6, 2023. We found the level of fault-fracture groundwater in the territory of Kryvbaswas affected bythe earthquakes. The calculation of the propagation velocity in the upper part of the lithosphere of the rock deformation front showed a value of ≈19.0 km/min (0.5 km/min).Concurrently, a decrease in the groundwater level by 2—3 cm was recorded, making it possible to conclude that after the earthquake, short-period stretchings of the earth’s crust occurred, both in the zone of the Kryvyi Rih—Kremenchutsky fault and over the Ukrainian Shield, in in general.
 The calculated amplitude-frequency characteristics for the geological environment on the territory of Kryvyi Rih revealed that the maximum acceleration of seismic vibrations on the free-soil surface increases relative to bedrock by about 4 times in the frequency range from 1.2 Hz to 1.75 Hz.

Dual-antenna GNSS-aided robust MEMS IMU initial alignment under the earth-centered-earth-fixed frame

The micro-electro-mechanical system (MEMS), with its small size, low cost and low power, has attracted widespread attentions in recent year, and the initial alignment of the inertial measurement unit (IMU) is an indispensable step before the navigation computation. In the traditional alignment methods with only the velocity measurements, the yaw angle is subject to divergence under low dynamic scenarios, and the measurements are also susceptible to the external environments. Furthermore, the navigation frame (n frame) is usually chosen as the reference frame. Although intuitive, it is more computationally complex compared with the earth-centered-earth-fixed frame (e frame). Therefore, to improve the alignment performance and computational efficiency, a robust MEMS IMU initial alignment method with yaw assistance under the e frame is proposed. In this method, to address the issues of the yaw divergency and computational inefficiency in the traditional methods, the relationship between the yaw angle, derived from dual-antenna global navigation satellite system baseline solution, and IMU error is derived and incorporated into the state space model with e frame as the reference frame. Besides, a robust extended Kalman filtering is adopted to further improve the system’s performance of outlier resistance, whose robust factors are determined by the Institute of Geodesy and Geophysics Ⅲ model. To validate the performance of the proposed method, two field experiments with the velocity of about 0.7 m s−1 and 1.5 m s−1 was conducted, and the collected data were processed for contrastive analysis. The results show that the effectiveness of the proposed method at suppressing yaw angle divergence and improving the alignment accuracy by resisting outliers under low dynamic scenarios compared with the traditional method. Moreover, the elapsed time is reduced by about 11% when the reference frame in data processing is switched from the n frame to the e frame.

A Mediterranean drifter dataset

Abstract. Over a hundred experiments were conducted between 1998 and 2022 in the Mediterranean Sea using surface Lagrangian drifters at coastal and offshore levels. Raw data were initially unified and pre-processed manually by eliminating spikes and wrong positions or date/time information. The integrity of the received data packages was checked, and incomplete ones were discarded. Deployment information was retrieved for each drifter and integrated into the PostgreSQL database, realized and maintained by the National Institute of Oceanography and Applied Geophysics (OGS) in Trieste (Italy). This database also collects a variety of metadata about the drifter model, project, owner, and operator. Subsequently, data were processed using standard procedures of editing and quality control developed for the OGS drifter dataset to remove spikes generated by malfunctioning of the sensors and to obtain files with common characteristics. Drifter data and plots of each track were also visually checked to remove any point not identified by the automatic procedure and which were clearly erroneous. Drifter trajectories were split into two or more segments that are considered different deployments in the case of specific drifter behaviour. Data were interpolated at defined time intervals providing a dataset of 158 trajectories, available from the public open-access repository of SEA scieNtific Open data Edition (SEANOE) at https://doi.org/10.17882/90537 (Ribotti et al., 2022), in two versions (one compliant with the Copernicus format and the other one usable with Panoply netCDF viewer), and of SeaDataNet at https://cdi.seadatanet.org/search/welcome.php?query=2610&query_code={9F00DF80-1881-42DD-9DF1-B9BD0282F2B0} (last access: 5 October 2023).

Velocity anisotropy measured on the spherical specimens: History and applications

The anisotropy of elastic properties, including seismic velocities, has already been investigated in the lab over past seven decades. Here, we present a review related to the development of a unique apparatus for the detailed measurement of seismic velocity anisotropy. Its originality lies in measuring velocities on spherical specimens, which allows for determination of the velocity anisotropy as a function of confining pressure loading with high resolution. The 132 directions, covering the sphere in a regular 15° net of meridians and parallels, have proven to be optimal with respect to common heterogeneities of investigated rocks. The device was designed and the first measurements were performed by a research team of the Institute of Geophysics in Prague (Babuška, Pros and Klíma) in 1968, shortly following many pioneer velocity anisotropy studies. Since then, almost 100 papers have been published using the velocity anisotropy measured with this unique device. The review consists of three separate but mutually interconnected parts: (i) historical development; (ii) microstructural insights from an ultrasonic velocity measurement perspective; (iii) macroscale applications to practical problems in geophysics, structural geology and rock mechanics.

Пространственно-временная изменчивость грозовой активности на территории Северного Кавказа

The analysis of the long-term observations (2008–2019) of thunderstorm activity in the North Caucasus using the High-mountain Geophysical Institute lightning detection network with LS8000 and LS7002 sensors is performed. Climatic and orographic regional factors forming the spatial heterogeneity of thunderstorm activity in the analyzed region are identified. It is shown that the number of thunderstorm events, their direction and lightning discharge intensity determine microphysical processes in the atmosphere, namely, the intensity of cloud and precipitation formation. Keywords: thunderstorm activity, climate, lightning, lightning detection network, precipitation, radar High-

Differentiation of the Bazhenov Formation Bitumoids in the North-Surgut Region during Generation and Migration

Abstract —The Bazhenov Formation of the Western Siberian oil-and-gas province is currently one of the key objects of potential growth in oil reserves and production. Here we present results of a geochemical study of the Bazhenov Formation according to the methodology developed at Trofimuk Institute of Petroleum Geology and Geophysics, Novosibirsk (IPGG SB RAS) for rocks highly enriched in organic matter. The features of the group and hydrocarbon compositions of the bitumoids that are filling open and closed pores of the Bazhenov Formation rocks from the North-Surgut region were considered. It has been established that most of the naphthides are in a free (phase-segregated) or sorbed state in a closed pore space. The open pores contain the most mobile components of bitumoids, redistributed from closed pores during the primary migration and remained after the secondary migration of naphtides from the Bazhenov Formation to the Berriasian–lower Aptian reservoirs (A and B strata groups). The methodology used in this work allows determining intervals with increased open porosity and oil saturation in the section of the Bazhenov Formation (silicites and carbonates) by the volume of pore space occupied by open-pore bitumoids.

Multisite evaluation of physics-informed deep learning for permafrost prediction in the Qinghai-Tibet Plateau

Prediction of the permafrost ground temperature is challenging due to its complex nonlinear process. Coupling physical models and machine learning has shown great potential in big data analysis, but its performance in permafrost prediction is still unclear. In this study, we proposed a physics-informed deep learning framework (i.e., PI-LSTM) to predict permafrost ground temperature profiles. The framework combines physical information with a long short-term memory (LSTM) network by two-stage training (pretraining and fine-tuning). The output of a Geophysical Institute Permafrost Laboratory 2 (GIPL2) model was used to pretrain the LSTM model. Borehole ground temperature measurements were used to fine-tune the pretrained LSTM model. Validation at multiple sites in various situations in the Qinghai-Tibet Plateau (QTP) shows that the accuracy and efficiency of the PI-LSTM model are dramatically higher than those of the original LSTM or GIPL2 model. Depending on the fine-tuning data sampling frequencies, the performance of the PI-LSTM model improved by an average of 27% (6–56%) and 69% (64–71%) compared to the LSTM and GIPL2 models, respectively. Even when only one year of observations was used to fine-tune the model, the RMSE of the simulated near-surface ground temperature profiles in the next decade did not substantially decline. The incorporation of physical information also contributes to the simulation efficiency. The PI-LSTM model converges faster than the LSTM model, and the training epochs are reduced by 70% (67–73%) during the fine-tuning step. This study demonstrates that integrating physical information into deep learning is promising for improving permafrost predictions.

Meteorological impact on gravimeter and seismometer readings

Background. The density of atmospheric air varies with temperature. Therefore, variations in the atmospheric layer temperature leads the emergence of local gravity anomalies. The amplitude of such anomalies can exceed ±0.1 mGal. The results obtained by the Arti Geophysical Observatory(Yekaterinburg, Russia) on the non-tidal variations of gravity confirm the influence of temperature variations on gravimeter readings, which may significantly exceed the calculated data. Aim. To assess the impact of weather changes on seismic and gravity fields.Materials and methods. At the RAS Bishkek Geodynamic Test Area (Bishkek, Kyrgyzstan), RAS Institute of Geophysics (Yekaterinburg, Russia) and Zapolye Observatory (Vladimir, Russia), gravity was measured by CG-5 AUTOGRAV gravimeters. At the Shults Cape (Vladivostok, Russia), Arti (Yekaterinburg, Russia) and BFO (Black Forest, Germany [10]) observatories, gravimetric measurements were conducted by La Coste & Romberg tidal gravimeters. Results. Variations in the atmospheric layer temperature were found to lead to the emergence of local gravity anomalies. The amplitude of such anomalies can exceed ±0.1 mGal. The results obtained by the Arti Geophysical Observatory (Yekaterinburg, Russia) on the non-tidal variations of gravity confirm the influence of temperature on gravimeter readings, which may significantly exceed the calculated data. Conclusion. Meteorological processes, such as liquid-water content and the Earth’s atmospheric temperature, affect the readings of gravimeters and seismometers. The atmospheric air density varies with temperature. Along with temperature, gravimeters and seismometers are affected by pressure, humidity and water content of the atmosphere. This is related to atmospheric deformations under the influence of the Moon and the Sun. Meteor streams and their impact on the Earth’s atmosphere have the greatest influence on the readings of gravimeters and seismometers.

New Functionalities and Regional/National Use Cases of the Anomaly Hotspots of Agricultural Production (ASAP) Platform

The Anomaly hotSpots of Agricultural Production (ASAP) Decision Support System was launched operationally in 2017 for providing timely early warning information on agricultural production based on Earth Observation and agro-climatic data in an open and easy to use online platform. Over the last three years, the system has seen several methodological improvements related to the input indicators and to system functionalities. These include: an improved dataset of rainfall estimates for Africa; a new satellite indicator of biomass optimised for near-real-time monitoring; an indicator of crop and rangeland water stress derived from a water balance accounting scheme; the inclusion of seasonal precipitation forecasts; national and sub-national crop calendars adapted to ASAP phenology; and a new interface for the visualisation and analysis of high spatial resolution Sentinel and Landsat data. In parallel to these technical improvements, stakeholders and users uptake was consolidated through the set up of regionally adapted versions of the ASAP system for Eastern Africa in partnership with the Intergovernmental Authority on Development (IGAD) Climate Prediction and Applications Centre (ICPAC), for North Africa with the Observatoire du Sahara et du Sahel (OSS), and through the collaboration with the Angolan National Institute of Meteorology and Geophysics (INAMET), that used the ASAP system to inform about agricultural drought. Finally, ASAP indicators have been used as inputs for quantitative crop yield forecasting with machine learning at the province level for Algeria’s 2021 and 2022 winter crop seasons that were affected by drought.