The problem of adequate quantitative analysis of anthropogenic film pollution of water areas according to synthetic aperture radar (SAR) satellite imagery is addressed here. A quantitative analysis of anthropogenic film pollution (AFP) in the studied coastal water areas of the north sector of the Black Sea and Avacha Gulf has been conducted. The analysis utilized a method that involved the statistical processing of data related to AFP identified within the cells of a regular spatial grid. Time series of Sentinel-1 SAR satellite imagery were used as initial data. Spatiotemporal distributions of the proposed quantitative criterion (eAFP, ppm) have been calculated and analyzed. This criterion characterizes the intensity of AFP impact within the selected regions of marine waters based on measuring the relative frequency of an AFP event. Among them, the area of the emergency fuel oil spill that occurred in 2024–2025 near the Kerch Strait was investigated (eAFP values near the wreckage of tankers reached ~13,000 ppm), as well as the area of the emergency oil spill near the Novorossiysk terminal that occurred in 2021 (eAFP ≤ 6000 ppm). Accidents led to an approximately 3–6-fold increase in eAFP values against the background level of 0–2000 ppm. The spatiotemporal variability of eAFP across various water areas and under different conditions has been demonstrated and discussed.

The Philippine Sea, located at the edge of the northwestern Pacific Ocean, possesses complex seabed topography. Developing a high-precision bathymetric model for this region is of paramount importance, as it provides fundamental geoinformation essential for Earth observation and marine scientific research, including plate motion, ocean circulation, and hydrological characteristics. The gravity–geologic method (GGM), based on marine gravity anomalies, serves as an effective bathymetric prediction technique. To further strengthen the prediction accuracy of conventional GGM, we introduce the improved GGM (IGGM). The IGGM considers the effects of regional seafloor topography by employing weighted averaging to more accurately estimate the short-wavelength gravity component, along with refining the subsequent modeling of long-wavelength gravity component. In this paper, we focus on seafloor topography modeling in the Philippine Sea based on the IGGM, combining shipborne bathymetric data with the Scripps Institution of Oceanography (SIO) V32.1 gravity anomaly. To reduce computational complexity, the optimal parameter values required for IGGM are first calculated before the overall regional calculation, and then, based on the terrain characteristics and distribution of sounding data, we selected four representative local sea areas as the research objects to construct the corresponding bathymetric models using GGM and IGGM. The analysis indicates that the precision of the IGGM models in four regions is improved to varying degrees, and the optimal calculation radius is 2′. Based on the above finding, a high-precision 1′×1′ bathymetric model of the Philippine Sea (5–35° N, 120–150° E), known as the BAT_PS model, is constructed using IGGM. Results demonstrate that the BAT_PS model exhibits a higher overall precision compared to the General Bathymetric Chart of the Oceans (GEBCO), topo_25.1, and DTU18 models at single-beam shipborne bathymetric points.

Using Sentinel-1 satellite radio interferometry data, the geodynamics in the area of the epicenter of the destructive Mw = 6.8 earthquake that occurred in Morocco on September 8, 2023, were studied using the Stacking-InSAR method applied to 801 interferograms. Over the period from January 2019 to September 2023, local surface subsidence with an average speed of 1.5 cm/year was discovered, and the maximum speed was identified in 2023 and amounted to 24 cm/year, for areas with a developed melioration system located above aquifers. Based on an integrated analysis of changes in the water equivalent thickness, measured from satellite gravimetric data for 2000–2023, and the amount of precipitation, it was found that the surface subsidence was due to a huge irrigation draft. Assuming the similarity of shapes of isoseists of earthquakes with close epicenters, a comparison of the isoseists of earthquakes that occurred in 2014 and 2023 was carried out, which made it possible to identify the expansion of the contours of the isoseists towards the descending surface areas for the earthquake from 2023. This process, along with the tectonic movements of the Eurasian and Nubian plates, is believed to increase the stress-strain state between two aquifers, what caused the Mw = 6.8 earthquake in Morocco on September 8, 2023.

The paper addresses the spatiotemporal variability of anthropogenic film pollution (AFP) in Avacha Gulf near the Kamchatka Peninsula based on satellite synthetic-aperture radar (SAR) imagery. Coastal waters of the study area are subject to significant anthropogenic impacts associated with intensive marine traffic, as well as the flow of household and industrial wastewater from factories located on the coast. A quantitative approach to the registration and quantitative analysis of spatiotemporal AFP distributions was applied. This approach is based on the processing of long-term time series of SAR imagery, taking into account inhomogeneous observation coverage and changing hydrometeorological conditions of different regions of water areas in various time periods. In total, 318 cases of AFP were detected in 2014–2023 in Avacha Gulf, covering 332 km2 of the total area (~3% of the water area) based on the 1134 processed radar Sentinel-1A/B scenes. The average value of AFP exposure, e, was about 93 ppm, evidencing the high level of AFP in the studied water area (comparable to areas of the Black Sea with intensive marine traffic, for which e was previously determined to be between ~90 and ~130 ppm). An interannual positive trend was revealed, indicating that over the 10-year period under study, the exposure of the waters of Avacha Bay (the most polluted part of Avacha Gulf) to AFP increased ~3-fold. An analysis of AFP spatial distributions and marine traffic maps indicates that this type of activity is a significant source of anthropogenic film pollution in Avacha Gulf (including Avacha Bay). It was shown that the generated quantitative information products using the introduced AFP exposure concept can be interpreted and used, for example, for making management decisions.

Nowadays, global remote sensing studies of tropical forest parameters are relevant for assessing carbon sequestration, whereas boreal forests receive little attention. This is due to the current idea that forests with greater aboveground biomass absorb more carbon. However, new research indicates that rapidly growing young forests take up more carbon than mature ones. Therefore, it is necessary to develop universal methods of remote reforestation/afforestation monitoring. The existing reforestation methods rely on the separate analysis of multispectral optical images and radar data. Here, we propose a method for analyzing the joint dynamics of NDVI (or the Normalized Burn Ratio, NBR) and the radar vegetation index (RVI) on a 2D plot for a test reforestation site. NDVI and NBR time series were derived from Landsat-5,8 data, and the RVI was derived from ALOS-1,2 and PALSAR-1,2 for 2007–2020 using the resources of Google Earth Engine. The quantitative parameters to evaluate the degree of reforestation and changes in the species composition of young trees have been suggested. The suggested method enables a more thorough evaluation of reforestation by measuring the coupled dynamics of the projective cover of young trees and aboveground biomass.

Anomalously intensive gas seeps on the sea surface due to damage to Nord Stream 1 and Nord Stream 2 underwater gas pipelines in the Baltic Sea have been analyzed using optical (Kanopus-B and Sentinel-2B) and radar (Sentinel-1A) satellite images. Positive contrasts of NRCS (up to 7.5 dB) registered by Sentinel-1A radar and of spectral reflectance (up to 0.73 units) registered by Kanopus-B and Sentinel-2B optical sensors have been detected in the area of such gas seeps. Those seeps’ features were revealed on the sea surface, namely dome-shaped swells, fountains, vortices, foam, wave breaking, surface wave structure disturbance, and wind shadow. Taking into account the volume and density of gas located in the damaged pipelines, it is shown that the total volume of methane release was no more than ~ 0.51 Tg, i. e., less than 0.1% of the annual global methane emissions into the atmosphere.

The geodynamics at the epicenter of the destructive Mw = 6.8 earthquake that occurred in Morocco on September 8, 2023, was studied by the Stacking-InSAR method applied to 801 interferograms based on the Sentinel-1 synthetic aperure radar (SAR) data. Over the period from January 2019 to September 2023, local subsidence of the surface with an average velocity of 1.5 cm/yr was discovered. The maximum velocity obtained in 2023 reached 24 cm/yr in the areas with a developed melioration system located above aquifers. Based on the integrated analysis of variations in the water equivalent thickness measured from the 2000–2023 satellite gravimetric data and the amount of precipitation, the surface subsidence was found to be due to a significant withdrawal of water from aquifers. Assuming similar shapes of isoseists of earthquakes with close epicenters, the isoseists of the earthquakes that occurred in 2014 and 2023 were compared. The data obtained made it possible to identify the expansion of isoseist contours toward the descending surface areas of the 2023 earthquake. This process, along with the tectonic movements of the Eurasian and Nubian plates, is believed to have increased the stress–strain state between two aquifers and finally caused the Mw = 6.8 earthquake in Morocco on September 8, 2023.

The brief communication demonstrates the potential for quantitative assessment of forest canopy height dynamics in mature and young pine forests on a plain using the method of weighted summing of time series of unwrapped interferometric phases. The latter were obtained using a modern approach based on cloud computations. By comparing the rates of canopy height growth for the years 2017, 2018, and 2019, it has been confirmed that the growth rate is influenced by the amount of precipitation in May-July of the respective year.

The development of a method of retrieval of two-dimensional spatial spectra of sea wave elevations is proposed on the basis of high-resolution satellite imagery, which permits estimation of the angular distributions of wind wave energy. The method is validated by the results of a comprehensive experiment that involved satellite imaging of the Black Sea water area using optical instruments and sea truth measurements under controlled conditions from a stationary oceanographic platform. The angular distribution of sea wave energy retrieved by spatial spectra of satellite imagery fragments was compared with the results of measurements of the frequency-angular spectra collected using an array of string wave recorders. It is shown that the results of remote and in situ measurements are consistent in the range of sea wavelengths from 2.8 to 30 m and that the average absolute error is 0.3.

Climate change in the Arctic region is more significant than in other parts of our planet. One of the manifestations of these changes is crater creation with blowouts of a gas, ice and frozen soil mixture. In this context, dynamics studies of long-term heaving mounds that turn into craters as a result are relevant. A workflow for detecting and assessing anomalous dynamics of heaving mounds in the Arctic regions is proposed. Areas with anomalous increase of ALOS-2 PALSAR-2 synthetic aperture radar (SAR) backscattering intensity are detected in the first stage. These increases take place due to sudden changes in local terrain slopes when the scattering surface (mound slope) turns toward the radar. Radar backscattering intensity also rises due to depolarization at newly formed frost cracks. Validation of the detected anomaly is carried out at the second stage through a comparison of multi-temporal digital elevation models obtained from bistatic radar interferometry TerraSAR-X/TanDEM-X data. At the final stage, the deformations are assessed within the detected areas using differential SAR interferometry (DInSAR) technique by ALOS-2 PALSAR-2 data. The magnitude of the heaving along the line of sight (LOS) was 22–24 cm in the period from January 2019 to January 2020. In general, effectiveness for detecting the perennial heaving mounds and the rate assessment of their increase were demonstrated in the suggested workflow.

Studies of variations in the parameters of various geophysical fields during the preparation of destructive earthquakes that occurred in Turkey in February 2023 with magnitudes of 6 ≤ M ≤ 7.8 are carried out using satellite data. It has been found that anomalies of these parameters manifested themselves from 34 to 25 days before the earthquakes as a sharp decrease in the values of relative humidity (RHS) and outgoing longwave radiation (OLR), as well as in an increase in the density of local lineaments. An increase in the surface skin temperature (SST), surface air temperature (SAT), RHS, and OLR, as well as in the values of the aerosol optical depth (AOD) and ionospheric total electron content (TEC), was revealed 19–9 days before the analyzed seismic events. In the period from 5 to 2 days before these earthquakes, a decrease in the SST, SAT, the flux of OLR, and the ionospheric TEC, as well as an increase in RHS and in the length of the secants of the rose diagrams of regional lineaments, were recorded. Quantitative characteristics of these anomalies are determined.

Changes in thermal fields during the period leading up to and during earthquakes (magnitude of 4.2–4.8) in the North Caucasus between 2017 and 2022 are studied based on satellite data. The Earth’s surface and near-surface air temperatures, outgoing long-wave radiation, and relative humidity near the surface recorded from space are analyzed. The changes in thermal fields during the preparation of seismic events are compared for earthquakes with epicenters located in zones of similar geological structures, such as the fold-block structures of the Greater Caucasus and the Pre-Caucasian foredeep. Similarities between the variations in the temperature, relative humidity, and fluctuations of outgoing longwave radiation are revealed for a number of earthquakes. The most similar character of the variations is for the normalized values of outgoing long-wave radiation during the preparation of all seismic events analyzed, despite the different positions of their epicenters. Hence, these parameters can be used as short-term precursors of seismic events detectable from space.

Displacement velocity fields of the block-fault structure are constructed and the main geodynamic processes in the area of the East Anatolian fault are revealed based on the results of processing of 437 radar interferograms obtained from the Sentinel-1 radar in the period from the beginning of 2018 to disastrous seismic activity in February 2023 in Turkey by Stacking InSAR method. Anomalous block displacements along this fault have been identified, which are timed to the earthquake of January 24, 2020 (M = 6.7). Zones of stress-strain state of the main blocks in the period preceding the earthquake have been established using cluster analysis of time series of velocity fields. It is shown that the epicenters of February 2023 earthquakes are located in these zones. It is concluded that it is necessary to use such a technique to assess the stress-strain state in order to predict seismic activity.

A rapidly developing high-amplitude shear deformation anomaly in the upper crustal interval (at depths of up to 10 km), the so-called “intense deformation quantum,” with a maximum increase in deformation by two orders of magnitude within half a month, has been identified within a geomechanical model of Southern California by detailed analysis of the local stress–strain features. These “quanta” can be integral elements of the entire deep deformation process associated with seismicity. The quantitative characteristics of deep deformation “quanta” and the conditions for their occurrence are discussed.

Long-term changes in thermal fields were studied before and during strong earthquakes with magnitudes from 5.1 to 5.6 that occurred in the region of the Baikal rift zone in 2008–2022. Satellite data were used for these studies. For the analysis we used the values of land surface temperature, temperature of the near-surface layer of the atmosphere, outgoing long-wave radiation, and relative humidity recorded using the AIRS instrument mounted on the Aqua satellite. During the periods of preparation and occurrence of these seismic events, anomalous variations in the parameters of thermal fields registered with satellite were revealed. They exceeded the average long-term values: for land surface temperature and temperature of the near-surface layer of the atmosphere by 5–10%, for outgoing long-wave radiation by 11–15%, and for relative humidity by 6–10%. A strong negative correlation was found between changes in the temperature of the near-surface layer of the atmosphere and relative humidity (correlation coefficient of –0.75), as well as antiphase oscillations between the values of the outgoing long-wave radiation and relative humidity. The obtained results can be used for studies of the precursor variability of thermal fields during monitoring of seismic hazard zones.

The spatiotemporal distributions of wildfire areas and FRP values for the territory of Russia and its large regions (the European part of Russia, as well as the Ural, Siberian, and Far Eastern Federal Districts) during 2001–2022 were analyzed using satellite data. For the territory of Russia, there was a decreasing trend in annual burned areas and a small increase in average hotspot FRP. At the same time, the largest annual burned areas in the territory of Russia were recorded in 2008 (295.2 thous. km2), 2002 (272.4 thous. km2), 2006 (261.2 thous. km2), and in 2012 (258.4 thous. km2). It was found that during the studied period, 90% of fire hotspots in Russia had a maximum FRP < 100 MW. The most intense wildfires (FRP > 1500 MW) amounted to only 0.1% and were detected mainly in the Siberian and Far Eastern Federal Districts. Interconnections between large wildfires and meteorological factors, including blocking activity in the atmosphere, were revealed.

—The geomechanical modeling of the stress-strain dynamics before the 2019 M = 7.1 Ridgecrest earthquake, Southern California, revealed an alternating pattern of maximum displacement anomalies that develop around the ends of the future rupture, simulating the process of “swinging” in the epicentral zone of the earthquake. These results, together with the existing theoretical concepts of crustal block structure with block interaction, are used to build a “swing” geomechanical model based on the stick-slip phenomenon in a three-block configuration. The parameters of the model are related to the rheological properties of the Earth’s crust in the area of destruction of the bridging isthmus (a patch), which determines the source size of the seismic event.

Harmful algal blooms (HABs) adversely impact aquatic organisms, human health, and the marine economy. The need to understand the origins and mechanisms of HAB occurrence and development determines the relevance of the study of these phenomena, including using remote sensing methods and assets. Here we present the results of a comprehensive study of conditions and precursors of some intense HABs detected in the water areas near the island of Chiloe (Chile, 2016), near the Kamchatka Peninsula (Russia, 2020), near the island of Hokkaido (Japan, 2021), among others. The study involves statistical analysis of long-term satellite and model data arrays on significant parameters of the marine environment and near-surface atmosphere, as well as empirical modeling of HAB risks. Information products on the following environmental parameters were used: sea surface temperature (SST, NOAA OISST, since 1981), the level of photosynthetically active radiation (PAR) and chlorophyll-a concentration (MODIS Ocean Color SMI, since 2000), sea surface salinity and height (HYCOM, since 1993), and near-surface wind speed and direction (NCEP CFSv2, since 1979). Quantitative assessments of the dynamics of informative criteria were applied. The key criterion is the ratio (Δσ) of the absolute deviation of the studied parameter from the expected norm to the RMS deviation of its values. Intense HABs were often preceded by excessive SST (up to Δσ ~1.99) and PAR (up to Δσ ~2.25) values, as well as low near-surface wind speed (up to Δσ ~−1.83). These environmental parameters considerably contribute to HAB generation and intensification. An approach and empirical function were proposed that allow us to assess the risk of HAB phenomena and reveal their precursors. Using the proposed approach and empirical function, the precursors of ten HABs were identified, nine of which were confirmed by in situ data. The results can be used as a tool for forecasting and studying the conditions for the occurrence of HABs, representing one of the promising directions for monitoring these dangerous phenomena.

Anomalous variations in various geophysical fields (lineament systems, thermal fields, and ionospheric parameters) during the earthquake with the magnitude M = 5.6, which took place near Lake Baikal on September 22, 2020, and during its preparation, are studied. Features of the geophysical fields are described. Combined analysis of anomalous variations in the geophysical fields in the lithosphere, atmosphere, and ionosphere during the earthquake preparation is carried out. Based on the analysis results, we detect anomalous variations in the lineament systems 15 and 6 days before; in the thermal fields 15 and 14 days before; and in the ionospheric parameters 8, 7, and 6 days before the earthquake. Correspondences are found between the occurrence of the maxima of the lineament systems and the thermal fields 15 and 6 days before the earthquake and changes in the state of the ionosphere and thermal fields 9–10 days and 4 days before the earthquake.

Displacement velocity fields of the block-fault structure are constructed and the main geodynamic processes in the area of the East Anatolian Fault (EAF) are revealed based on the results of the processing of 437 radar interferograms obtained from the Sentinel-1 radar in the period from early 2018 until the beginning of the destructive seismic activity in February 6, 2023 in Turkey by the Stacking-InSAR method. Anomalous block displacements along this fault have been identified; they are timed to the earthquake of January 24, 2020 (Mw = 6.7). Zones of stress–strain state of the main blocks in the period preceding the earthquake have been determined using the cluster analysis of time series of velocity fields. It is shown that the epicenters of the February 2023 earthquakes are located in these zones. A conclusion is made about the necessity of using such a technique to estimate the stress–strain state in order to predict seismic activity.