Search Results (166)

Because of the active influx of chemical compounds into the marine environment, a significant portion is transformed and accumulates in bottom sediments (BS), posing a threat to benthic organisms. The eastern coast of the Kamchatka Peninsula, with its characteristic volcanic, seismic, and gas–chemical features, is of particular interest to our research. This study is the first to assess the cyto- and genotoxicity of BS in coastal waters off the eastern coast of the Kamchatka Peninsula using biotesting on representatives of the benthic community (the mussel Mytilus trossulus and the sand dollar Scaphehinus mirabilis). Of the aqueous extracts exposure of BS from all stations, M. trossulus showed destabilization of lysosomal membranes in gills and digestive gland cells. It was shown that aqueous extracts from BS of Kamchatka Bay (station 1) and Avachinskaya Bay (station 3) had no negative effect on DNA molecules in the gills and digestive gland cells of mussels, and the values obtained corresponded to the control. Extracts from BS of Kronotsky Bay (station 2) and Avacha Bay (station 4) damaged the integrity of the genome in the cells of the gills M. trossulus and sperm of S. mirabilis. The level of DNA damage in sperm increased by 3 and 3.5 times, respectively, compared with that in control gametes. The results of the biotests on two biological models show that sediments from Kronotsky Bay and Avacha Bay exhibit cytotoxicity and induce DNA damage in both somatic cells and gametes. Full article

An integrative study of material from Yunnan Province, China, revealed two new Lophozia species. These species and several other representatives of the genus known from East Asia form a distinct clade within the phylogenetic structure of Lophozia. Descriptions, photographs, and comments regarding the morphological characteristics of the new taxa are provided. Lophozia neglecta is characterized by pink gemmae (another taxon with similar gemmae is East Asian L. koreana), whereas L. vinacea is characterized by vine-purple gemmae, which were previously unknown in the genus. Additionally, molecular analysis confirmed the occurrence of L. fuscovirens, a poorly known Lophozia taxon with brown gemmae, in the Kamchatka Peninsula. The taxonomic diversity of Lophozia in East Asia comprises 12 species belonging to various distribution groups, including the Sino-Himalayan and broadly East Asian groups. Full article

Blue honeysuckle (Lonicera caerulea) is widespread across the Eurasian continent, mainly in northern latitudes. Its berries are a rich source of biologically active compounds. In this study, plant samples collected in four regions of Russia separated by more than 10,000 km were examined in detail: St. Petersburg, Kamchatka, Magadan and the Far East (Vladivostok). The study was unique in that it covered almost the entire Eurasian continent in northern latitude, which had not been previously presented in other scientific studies. The study revealed the presence of 110 polyphenols and 34 compounds belonging to other chemical groups. In particular, honeysuckle berries were rich in polyphenols, including flavonoids, flavanones, flavanols, flavan-3-ols, anthocyanins, stilbenes, and lignans. The method of tandem mass spectrometry was used to identify biologically active substances from the extracts, which allows obtaining fairly accurate results. The metabolomic composition of L. caerulea berries originating from Kamchatka and Magadan showed the greatest diversity of polyphenols, which is associated with special northern climatic conditions and associated stress factors for plants. The results we obtained provide new data on the composition of the honeysuckle berry metabolome. The wealth of biologically active substances in blue honeysuckle berries can be very interestingly used in the development of both biologically active additives for pharmaceutical use and for the development of functional and specialized nutrition products for various population groups. Full article

Abies nephrolepis and Picea jezoensis are native Pinaceae trees distributed in high mountainous regions of Northeast Asia (typically above ~1000 m a.s.l. on the Korean peninsula, northeastern China, Sakhalin, and the Russian Far East) and southern boreal forests, vulnerable to climate change and human disturbances, necessitating accurate habitat identification for effective conservation. While protected areas (PAs) are essential, merely expanding existing ones often fail to protect populations under human pressure and climate change. Using species distribution models with current and projected climate data, we mapped potential habitats across Northeast Asia. Spatial clustering analyses integrated with PA and land cover data helped identify optimal sites and priorities for new conservation areas. Ensemble species distribution models indicated extensive suitable habitats, especially in southern Sikhote-Alin, influenced by maritime-continental climates. Specific climate variables strongly affected habitat suitability for both species. The Kamchatka peninsula consistently emerged as an optimal habitat under future climate scenarios. Our study highlights essential environmental characteristics shaping the habitats of these species, reinforcing the importance of strategically enhancing existing PAs, and establishing new ones. These insights inform proactive conservation strategies for current and future challenges, by focusing on climate refugia and future habitat stability. Full article

The new mineral achyrophanite (K,Na)₃(Fe³⁺,Ti,Al,Mg)₅O₂(AsO₄)₅ was found in high-temperature sublimates of the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with aphthitalite-group sulfates, hematite, alluaudite-group arsenates (badalovite, calciojohillerite, johillerite, nickenichite, hatertite, and khrenovite), ozerovaite, pansnerite, arsenatrotitanite, yurmarinite, svabite, tilasite, katiarsite, yurgensonite, As-bearing sanidine, anhydrite, rutile, cassiterite, and pseudobrookite. Achyrophanite occurs as long-prismatic to acicular or, rarer, tabular crystals up to 0.02 × 0.2 × 1.5 mm, which form parallel, radiating, bush-like, or chaotic aggregates up to 3 mm across. It is transparent, straw-yellow to golden yellow, with strong vitreous luster. The mineral is brittle, with (001) perfect cleavage. D_calc is 3.814 g cm^–3. Achyrophanite is optically biaxial (+), α = 1.823(7), β = 1.840(7), γ = 1.895(7) (589 nm), 2V (meas.) = 60(10)°. Chemical composition (wt.%, electron microprobe) is: Na₂O 3.68, K₂O 9.32, CaO 0.38, MgO 1.37, MnO 0.08, CuO 0.82, ZnO 0.48, Al₂O₃ 2.09, Fe₂O₃ 20.42, SiO₂ 0.12, TiO₂ 7.35, P₂O₅ 0.14, V₂O₅ 0.33, As₂O₅ 51.88, SO₃ 1.04, and total 99.40. The empirical formula calculated based on 22 O apfu is Na_1.29K_2.15Ca_0.07Mg_0.34Mn_0.01Cu_0.11Zn_0.06Al_0.44Fe³⁺_2.77Ti_1.00Si_0.02P_0.02S_0.14V_0.04As_4.90O₂₂. Achyrophanite is orthorhombic, space group P222₁, a = 6.5824(2), b = 13.2488(4), c = 10.7613(3) Å, V = 938.48(5) ų and Z = 2. The strongest reflections of the PXRD pattern [d,Å(I)(hkl)] are 5.615(59)(101), 4.174(42)(022), 3.669(31)(130), 3.148(33)(103), 2.852(43)(141), 2.814(100)(042, 202), 2.689(29)(004), and 2.237(28)(152). The crystal structure of achyrophanite (solved from single-crystal XRD data, R = 4.47%) is unique. It is based on the octahedral-tetrahedral M-T-O pseudo-framework (M = Fe³⁺ with admixed Ti, Al, Mg, Na; T = As⁵⁺). Large-cation A sites (A = K, Na) are located in the channels of the pseudo-framework. The achyrophanite structure can be described as stuffed, with the defect heteropolyhedral pseudo-framework derivative of the orthorhombic Fe³⁺AsO₄ archetype. The mineral is named from the Greek άχυρον, straw, and φαίνομαι, to appear, in allusion to its typical straw-yellow color and long prismatic habit of crystals. Full article

The magnetic field of the Sun is formed by the mechanism of hydromagnetic dynamo. In this mechanism, the flow of the conducting medium (plasma) of the convective zone generates a magnetic field, and this field corrects the flow using the Lorentz force, creating feedback. An important role in dynamo is played by memory (hereditary), when a change in the current state of a physical system depends on its states in the past. Taking these effects into account may provide a more accurate description of the generation of the Sun’s magnetic field. This paper generalizes classical dynamo models by including hereditary feedback effects. The feedback parameters such as the presence or absence of delay, delay duration, and memory duration are additional degrees of freedom. This can provide more diverse dynamic modes compared to classical memoryless models. The proposed model is based on the kinematic dynamo problem, where the large-scale velocity field is predetermined. The field in the model is represented as a linear combination of two stationary predetermined modes with time-dependent amplitudes. For these amplitudes, equations are obtained based on the kinematic dynamo equations. The model includes two generators of a large-scale magnetic field. In the first, the field is generated due to large-scale flow of the medium. The second generator has a turbulent nature; in it, generation occurs due to the nonlinear interaction of small-scale pulsations of the magnetic field and velocity. Memory in the system under study is implemented in the form of feedback distributed over all past states of the system. The feedback is represented by an integral term of the type of convolution of a quadratic form of phase variables with a kernel of a fairly general form. The quadratic form models the influence of the Lorentz force. This integral term describes the turbulent generator quenching. Mathematically, this model is written with a system of integro-differential equations for amplitudes of modes. The model was applied to a real space object, namely, the solar dynamo. The model representation of the Sun’s velocity field was constructed based on helioseismological data. Free field decay modes were chosen as components of the magnetic field. The work considered cases when hereditary feedback with the system arose instantly or with a delay. The simulation results showed that the model under study reproduces dynamic modes characteristic of the solar dynamo, if there is a delay in the feedback. Full article

Earthquakes cause enormous social and economic damage. Consequently, the seismic process requires regular monitoring and systematic forecasting of strong earthquakes. This study introduces an enhanced iteration of the method of the minimum area of alarm (MMAA), refined to advance earthquake forecasting technology closer to its practical application. In the new version, a forecast is considered successful when all target earthquake epicenters within a specified time interval are contained within predefined alarm zones. Our updated algorithm optimizes the probability of successfully detecting earthquakes across forecast cycles and the probability for subsequent periods. A case study from the Kamchatka region demonstrates the practical application of this systematic forecasting approach. We propose that this computational technology can serve as an operational tool for generating early warnings of potential seismic hazards, and a research platform for conducting detailed investigations of precursor phenomena. Full article

Catchment areas on volcanic territories in different regions are of great interest since they are enriched with nutrients that contribute significantly to coastal ecosystems. The Kamchatka Peninsula is one of the most active volcanic regions of the world; however, to date, the chemistry of its river waters and the state of its coastal ecosystems remain understudied in connection with volcanism. The two rivers under study are the largest in this region. The Kamchatka River, unlike the Penzhina River, drains volcanic territories, including the areas of the most active volcanoes of the Klyuchevskaya group of volcanoes and the Shiveluch Volcano. The mouth of the Kamchatka River has been shown to have DIP and DIN concentrations of 2.79–3.87 and 10.0–23.8 µM, respectively, during different seasons, which are comparable to rivers in urbanized areas with sewerage and agricultural sources of nutrients. It has been established that volcanoes form high concentrations of nutrients in the catchment area of the Kamchatka River. The Penzhina River has had very low DIP and DIN concentrations of 0.2–0.8 and 0.17–0.35 µM, respectively, near the mouth during different seasons, but high concentrations of DOC, at 5.9 mg/L in spring, which may be due to seasonal thawing of permafrost. During the period of increasing river discharge, seasonal phytoplankton blooms occur in spring and summer in bays of the same name, as shown using satellite data. The biomass of zooplankton in Penzhina Bay is at a level of 100 mg/L, while in Kamchatka Gulf, it exceeds 2000 mg/L. Thus, the biomass of zooplankton in the receiving basin, which is influenced by the runoff of the Kamchatka River with a volcanic catchment area in eastern Kamchatka, is 20 times higher than in the basin, which has a small nutrient flux with the river runoff in northwestern Kamchatka. This study demonstrates the connection between nutrient fluxes from a catchment area and the formation of seasonal phytoplankton blooms and high zooplankton biomass in the coastal area. We also study seasonal, year-to-year, and climatic variability of water discharges and hydrometeorological conditions to understand how nutrient fluxes can change in the foreseeable future and influence coastal ecosystems. Full article

Conditions of high-temperature volcano-related mineral formation are a source of the new and rare minerals and their associations; they are rather fragmentarily described for volcanic systems as a whole, except for several objects characterized in this regard. The study aim is to present the first results of the mineralogical study of atypical suprasubduction zone neoformation encountered from the Taketomi flank eruption (1933–1934) of the Alaid volcano (Kuril Islands), which has been studied through electron microprobe analyses and powder and single-crystal X-ray diffraction. The following mineral paragenesis is described: diopside, andradite, anorthite, wollastonite, esseneite, wadalite, rhönite-like mineral, fluorite, calcite, apatite, and atacamite. The parageneses of calcium silicates found in volcanic systems are usually interpreted as reworked crustal xenoliths and commonly associated with volcanoes that have a carbonate basement. However, carbonates have not been previously described at the base of the Alaid volcano. Even though the skarn nature of such a mineral paragenesis is possible, we suggest the important role of high-temperature volcanic gases along with the pyrometamorphic effect in the mineral-forming process at depth or in near-surface conditions (fumarole-like type in the form of a system of cracks and burrows). The described mineral paragenesis has not been previously documented, at least for the North Kuril Islands. A detailed mineralogical study of such formations is one of the important steps in understanding the functioning of magmatic systems, the circulation and transformation of natural matter, and mineral-forming processes. Full article

The aim of this study was to use a rapid and non-invasive spectrofluorimetric method to evaluate the qualitative changes occurring in stored Kamchatka berry preserves. Honeysuckle berries were preserved by freezing (−24 °C) and pasteurisation with and without sugar addition. Pasteurised samples were stored at 6 ± 1 °C and 22 ± 1 °C for 9 months. During storage, spectrofluorimetric spectra in the bioactive compounds’ fluorescence range were registered. The obtained synchronous spectra were used in a statistical analysis involving principal component analysis (PCA) and linear discriminant analysis (LDA). The analysis of both types of registered spectra indicated that sugar addition could stabilise some phenolic compounds, like gallic acid, p-coumaric acid, and phloridzin. Moreover, some differences in the degradation rate of each analysed compound were observed depending on the preservation method used. Besides the phenolic compounds, other fluorescent compounds like B-vitamins and chlorophyll forms were also observed. Pasteurisation caused the distinct degradation of protochlorophyll forms, whereas practically no changes in the amounts of vitamins B₃ and B₉ were observed. Based on the results of statistical analyses of PCA and LDA, the effect on the products’ composition was moderate for the storage time and relatively low in the case of the storage temperature. The obtained results indicated that spectrofluorimetry would be a useful method for the detailed characterisation of fruit products. Full article

Long-term observations in wells make it possible to study changes in groundwater pressure/level during individual earthquakes (seismo-hydrogeodynamic effects—SHGEs) over a wide range of periods of their manifestation. Information on the morphological features and durations of the SHGEs together with data on earthquake parameters form the basis for creating the unique typifications of SHGEs for individual observation wells. With reliable verification, such SHGE typifications provide the practical use of well observation data to predict strong earthquakes and assess their impact on groundwater. During long-term (1996–2022) precision observations of pressure/water level variations in wells of the Petropavlovsk–Kamchatsky test site (Kamchatka Peninsula, northwest Pacific seismic belt), SHGE typifications describing the manifestations of various types of SHGEs at the earthquakes in ranges of magnitudes M_w = 5.0–9.1 and epicentral distances d_e = 80–14,600 km were developed. At the same time, the issue of verifying created SHGE typifications for individual wells in relation to the strongest and closest earthquakes, accompanied by noticeable tremors in the observation area, is relevant. On 3 April 2023, an earthquake, M_w = 6.6 (EQ), occurred at an epicentral distance d_e = 67–77 km from observation wells. Various changes in the groundwater pressure/level were recorded in the wells: oscillations and other short-term and long-term effects of seismic waves, coseismic jumps in water pressure caused by a change in the static stress state of water-bearing rocks during the formation of rupture in the earthquake source, and supposed hydrogeodynamic precursors. The EQ was used to verify the SHGE typifications for wells YuZ-5 and E-1 with the longest observation series of more than 25 years. In these wells, the seismo-hydrogeodynamic effects recorded during the EQ corresponded to the previously observed SHGE during the two strongest earthquakes with M_w = 7.2, d_e = 80 km and M_w = 7.8, d_e = 200 km. This correspondence is considered an example of the experimental verification of previously created SHGE typifications in individual wells in relation to the most powerful earthquakes in the wells’ area. Updated SHGE typifications for wells E-1 and YuZ-5 are presented, showing the patterns of water level/pressure changes in these wells depending on earthquake parameters and thereby increasing the practical significance of well observations for assessing earthquake consequences for groundwater, searching for hydrogeodynamic precursors and forecasting strong earthquakes. The features of the hydrogeodynamic precursor manifesting in the water level/pressure lowering with increased rates in well E-1 before earthquakes with M_w ≥ 5.0 at epicentral distances of up to 360 km are considered. A retrospective statistical analysis of the prognostic significance of this precursor showed that its use for earthquake forecasting increases the efficiency of predicting earthquakes with M_w ≥ 5.0 by 1.55 times and efficiency of predicting earthquakes with M_w ≥ 5.8 by 2.34 times compared to random guessing. This precursor was recorded during the 92 days before the EQ and was identified in real time with the issuance of an early prognostic conclusion on the possibility of a strong earthquake to the Kamchatka branch of the Russian Expert Council for Earthquake Forecasting. Full article

The paper considers the results of experiments on localization of the sources of geoacoustic radiation generated in near-surface sedimentary rocks. Geoacoustic signals from sources were recorded by a spaced sensor system consisting of two combined receivers and a hydrophone. The system was installed near the bottom of a natural water body (Mikizha lake) in Kamchatka. Radiation sources were located by two methods, a triangulation survey and estimation of the signal arrival time difference from spaced receivers. Coordinates for more than 40 sources were measured, and their space distribution was mapped. As the result of the experiment, it was stated that geoacoustic radiation sources are located in bottom rocks at the depths up to 2.20 ± 0.25 m at the distances of up to 8 ± 0.25 m. Localization of geoacoustic radiation sources is topical for projecting a new alarm system for the notification on the possibility of strong earthquake occurrence. The results of the analysis of the frequency of rock AE source generation and accurate estimation of their location will be the basis of this system. Full article

The red king crab, Paralithodes camtscaticus, is a commercially significant crustacean that supports lucrative fisheries in Russia, the USA, and Norway. The western Kamchatka shelf, located in the Sea of Okhotsk, is home to one of the most important populations of the red king crab. In this study, we have conducted a review of the symbionts associated with P. camtscaticus in the waters off the Kamchatka Peninsula. A total of 42 symbiotic species belonging to 14 different phyla were identified in association with the red king crab. Out of these, 14 species were found to be parasitic to the red king crab, while the remaining 28 were either commensal or epibiont in nature. The taxa with the highest number of associated species included ciliates (11), crustaceans (8), and acanthocephalans (4). Our study found that red king crabs suffering from shell disease exhibited a more diverse symbiotic fauna and higher infestation indices as compared to healthy crabs, which were found to be free from parasites. Dangerous symbionts, such as dinoflagellates Hematodinium sp. and rhizocephalan barnacles Briarosaccus callosus, had low incidence rates, indicating that the red king crab population in the Sea of Okhotsk is in good condition with respect to population abundance, health, and recruitment and is not being adversely impacted by symbiotic organisms. Full article

Using the data of radon accumulation in a chamber with excess volume at one of the points of the Kamchatka subsurface gas-monitoring network, the change in radon flux density due to seismic waves and post-seismic relaxation of the medium is shown. A linear fractional equation is considered to be a model equation. The change of radon-transport intensity due to changes in the state of the geo-environment is described by a fractional Gerasimov–Caputo derivative of constant order. Presumably, the order of the fractional derivative is related to the radon-transport intensity in the geosphere. Using the Levenberg–Marquardt method, the optimal values of the model parameters were determined based on experimental data: air exchange coefficient and order of fractional derivative, which allowed the solving of the problems of radon flux density determination. Data in the temporal neighborhood of a strong earthquake with $M_w=7.0$, which occurred in the northern part of Avacha Bay on 17 August 2024, were used. As a result of the modeling, it is shown that the strong seismic impact and subsequent processes led to changes in the radon flux in the accumulation chamber. The obtained model curves agree well with the real data, and the obtained estimates of radon flux density agree with the theory. Full article

This study investigates the hypothesis that meteorological anomalies may precede earthquake events. Long-term time series of observations for air temperature, atmospheric pressure and precipitation at a meteorological station in Kamchatka are considered. Time series are subjected to Huang decomposition into sequences of levels of empirical oscillation modes (intrinsic mode functions—IMFs), forming a set of orthogonal components with decreasing average frequency. For each IMF level, the instantaneous amplitudes of envelopes are calculated using the Hilbert transform. A comparison with the earthquake sequence is made using a parametric model of the intensity of two interacting point processes, which allows one to quantitatively estimate the “measure of the lead” of the time instants of the compared sequences. For each IMF level, the number of time moments of the largest local maxima of instantaneous amplitudes which is equal to the number of earthquakes is selected. As a result of the analysis, it turned out that for the sixth IMF level (periods of 8–16 days), the “lead measure” of the instantaneous amplitude maxima of meteorological parameters in comparison with earthquake time moments significantly exceeds the inverse lead, which confirms the existence of prognostic changes in meteorological parameters in the problem of “atmosphere–lithosphere” interaction. This study reveals that certain meteorological anomalies can be a precursor for seismic activity. Full article