The Russian Karelia is a region that stretches along the Eastern periphery of the Fennoscandian crystal shield in the transition zone to the Russian plate. The main features of the topography are due to exposure of basement rocks that were subjected to processes of mainly subaerial denudation throughout almost the entire Phanerozoic. General irregularities of the relief are connected to the geologic structure and associated with an arc-shaped stage along the edge of the shield (“Polkanov flexure”) on which radially superimposed Riphean grabens, rejuvenated in the process of neotectonic activation and remain active until now. Structural and tectonic features of the terrain were the basis for an exogenous transformation of the terrain as a result of Pleistocene glaciation and post-glacial development of the territory: the distribution of zones of glacial denudation and accumulation, the spread of marine and lake basins, the formation and reorganization of the river network. Periodical changes of glacial and interglacial epochs determined vertical fluctuations of the surface under glacial load and after its removal with an amplitude of several hundred meters. The vertical movement vector is supplemented by the horizontal one, probably under the influence of spreading processes in the Atlantic Ocean floor. Reaching the surface of a rigid basement under conditions of vertical and horizontal stresses caused the reflection of the block-and-break structure in the topography and differentiated displacements along the faults, which were manifested in the form of strong earthquakes. Evidence of strong earthquakes are observed throughout the territory of Fennoscandia, although the problem of post-glacial seismicity, its spatial and temporal parameters and causes remains debatable. Numerous paleoseismic manifestations were found in the relief and underlying substrate-rock and loose deposits of the Russian Karelia: cracks, ruptures with vertical and horizontal displacements, rockfalls and landslides, lateral displacements of rock blocks, textures of liquefaction, injection dykes, traces of fluidization, mud-, and water-stone flows. The age of the discovered paleoseismic deformations varies mainly from the Late Glaciation to the Late Holocene, although there are traces of earlier earthquakes. The impact of earthquakes on the development of nature in the Late Neopleistocene and Holocene is underestimated: strong earthquakes could trigger significant transformations of the hydrographic network and landscapes.

Recent studies reveal an ongoing worldwide increase in a number of slope instability manifestations and their positive correlation with human activity. The latter involves construction activity as one of the most common trigger or susceptibility raising factors. In this study, we conduct a detailed analysis of an extensive and rapid transformation of a forest-covered mountain landscape and its response. The study area is a mountain sport cluster of the Winter Olympic Games-2014, which developed from scratch to a large tourist resort in just a few years. A time-series of aerospace images were used for a comprehensive mapping of the land cover changes and associated development of slope instabilities over 15 years, from a “pre-construction era” until now. We identify widespread deforestation and the land cover changes in upper chains of the fluvial systems to be the key drivers of the enhanced multiplication and intensification of the slope hazard processes. Completion of the active construction phase leads relatively quickly to a gradual natural stabilisation of the slope-located processes. However, the stream-located processes need several decades to regain a balance, because the increasing energy of small watercourses, due to growth of surface runoff coefficient, led to the transformation of longitudinal profiles of their channels. The obtained results provide a refined look at the anthropogenic influence on the slope instability occurrence and their short-time evolution in a mountain forest landscape. We also discuss the prospective course of events for this resort.

Khorlakel Lake is located in the central sector of the Greater Caucasus, on its northern macroslope. The closed lake lies at an altitude of 2045.0 m above sea level on a tectonically determined subhorizontal step with a height of 2020–2100 m a.s.l. associated with the frontal part of the thrust. Two cores were drilled, and 17 samples for radiocarbon dating were taken in 2017 in the deepest (≈8 m) part of the lake, which made it possible to create an age model for the range from 8000 to 500 yr BP. To interpret the stratigraphic–temporal sequence of lacustrine sediments, integrated geological and geomorphological studies in the catchments of the lake and Elbashi Creek and in adjacent territories were conducted. It was established that sedimentation in the lake is associated with the influence of the adjacent Elbashi Creek. A number of episodes of proluvial activation over the last 8500 years with the formation of an proluvial fan have been traced. This was followed by lacustrine sedimentation in a dammed lake, the relic of which is Khorlakel Lake. As a result, sedimentation in Khorlakel Lake and in the adjacent territories is clearly divided into two stages with a partition at ≈3 ka BP with the sedimentation of mainly nonorganic material at the first stage and organic material at the second stage. These stages include ten episodes, which are characterized by different sediments features and varying proportions of mineral and organic components. It was found that the initial lake during the Holocene decreased in size due to the uneven growth of the proluvial fan formed by sediments delivered from the catchment of Elbashi Creek. It has been established that some lithostratigraphic boundaries in the bottom sediments of Khorlakel Lake correlate with known strong earthquakes in the Elbrus region, while other boundaries relate to climatic events in the Central Caucasus that occurred during the Holocene. The complete termination of the connection between the current Khorlakel Lake and the Elbashi Creek catchment occurred in the last ≈1 ka BP.

The late-glacial and post-glacial history of the development of the White Sea coastal zone in the area of the Varzuga River estuary is considered as a result of the interaction of endogenous and exogenous factors of coastal morpholithogenesis. Based on the geomorphological investigations, study of Holocene deposits by lithostratigraphic, diatom, and radiocarbon analyses, as well as collection and analysis of published data, new results on the development of relief of the area for 13 cal ka have been obtained. The features of the regional hierarchical morphostructure and local post-glacial tectonics of the territory—the spatial relationships of blocks and the rate of vertical movements—were determined. The superimposed linear Nizhnevarzugskaya Depression, which determined the configuration of the Varzuga River estuary in the late-glacial and post-glacial periods, was identified for the first time. The influence of the spatial ratio of blocks and differentiated post-glacial uplift on the coastal morpholithogenesis was established. The course of changes in the relative sea level (RSL), development conditions, and morphodynamics of the open coast and the estuary of the Varzuga River were reconstructed, and new data on the rhythms of coastal geomorphologic processes (coastal, estuarine, and eolian) were obtained. Three stages of development of the coastal zone were identified, which corresponded to regional rhythms of changes in the relative sea level and climate. They are (I) the Late Glacial transgression and Early Holocene regression ( 12 to 9.8 cal ka BP), (II) the Middle Holocene Tapes transgression (7.8 to 4.9 cal ka BP), and (III) the Late Holocene regression (after 4.9 cal ka BP). The upper marine boundary of the Late Glacial transgression was traced at heights of 54 or 55 m to the west of the Nizhnevarzugskaya depression, 39 or 40 m to its east, and 22 to 25 m a.s.l in the depression. The shores of lower morphostructural blocks up to 10.2–9.8 cal ka BP were probably blocked by dead ice. During the Tapes transgression, the RSL reached a maximum ( 20 m a.s.l.) of 7.8 to 7.6 cal ka BP and slowly decreased to 15 m a.s.l. in the interval of 7.6 to 4.9 cal ka BP. The prevailing directions of sediment fluxes and the approaches of winds and waves became similar to those of today and have not changed significantly since that time. The main source of the coastal sediment supply was the erosion of glaciofluvial sediments and the input of sands from the seabed. In the interval of 4.9 to 1.7 cal ka BP, the RSL decreased to 5 m a.s.l. and then slowly approached the modern one. Activation of coastal ( 5–1 cal ka BP) and channel ( 4.9–4.7 to 3.6–3.4 cal ka BP) processes contributed to rapid filling of the estuary and formation of accumulative sand terraces on exposed banks. The sediment runoff of the Varzuga River became the main source of coastal sediment supply. After 2.3 cal ka BP, several stages in the intensification of eolian processes were revealed.

We studied sedimentary archives on the Karelian coast of the White Sea (area of the White Sea Biological Station, Moscow State University) from various objects-filling of the paleoseismic fault trench, marine terraces, and buried shell lenses-to obtain new data on the relative sea level dynamics in the Holocene in the areas where block tectonic movements took place. The specific features of the formation of subfossil malacofauna taphocenoses in Kandalaksha Gulf, changes in the sedimentation environment under the conditions of uplifting coast, and traces of strong seismicity in the late glacial and postglacial periods are also revealed.

Земля постоянно подвергается бомбардировке астероидами, от которых ее не всегда защищает атмосфера. Чем крупнее падающее тело, тем большие разрушения с ним связаны. Следы, оставленные на поверхности нашей планеты при падении небесных тел, называются «астроблемы». Для того чтобы оценить связанную с ними опасность, необходимо отличать их от других, внешне схожих форм рельефа, а также определять их возраст. В статье представлены результаты исследования котловины астроблемы озера Смердячее на востоке Московской области. Детально изучены строение вала и рельефа котловины астроблемы этого озера: приведены георадиолокационные разрезы, батиметрические и топографические профили. В работах использовались системы DGPS и беспилотных летательных аппаратов (БПЛА). В разрезах на валу озера были найдены и документированы деформации, связанные с разжижением песчаной толщи во время импактного события – падения метеорита. Были отобраны образцы нарушенного горизонта глин с органикой, свидетельствующие о его перемещении (опрокидывании) возрастом примерно 10.1 тыс. календарных лет. Полученные новые данные подтверждают гипотезу о космическом происхождении котловины озера Смердячее и уточняют возраст импактного события.

Detailed paleoseismogeological, morphotectonic, and tectonophysical studies using remote and ground surveys have been carried out on the islands of the Kuzokotsky Archipelago on the southwestern coast of Kandalaksha Bay of the White Sea. The following have been established: (a) kinematic parameters of seismic ruptures (including strike-slip faults; overthrust strike-slip faults along the ruptures of the general (NNW) direction corresponding to the side structures of the Kandalaksha graben; and strike-slip faults, faults, and tear faults along the ruptures of the WNW direction corresponding to the structures of the Velikaya Salma graben); (b) the correspondence of seismic rupture parameters (reverse strike-slip faults) to periodic changes in the tectonic stress field from northwest to northeast compression; (c) the inheritance of seismic deformations and the development of the latest morphostructure within the framework of the dominance of the structures of the Kandalaksha graben with the periodic activation of the Velikaya Salma graben; (d) three main stages of seismogenic renewal: (I) preglacial and the beginning of the late glacial, (II) late glacial, and (III) Holocene; (e) three main seismic episodes in the Late Holocene: 2.3–2.2, 1.5–1.4, and 0.5–0.4 ka BP; and (f) traces of maximum shaking corresponding to the IX+ and X seismic scale localized along the outer northern (to the Velikaya Salma strait) flank of the archipelago and related to all stages of seismogenic renewal.

The change in sediment yield is an important indicator of the natural environment dynamics, depending on the combination of landscape, tectonic and climatic conditions. Assessment of sediment yield often based on the results of studying the bottom sediments of mountain lakes with relatively compact catchments. However, for correct reconstructions, in addition to analyzing lake sediments, it is necessary to study the causes and mechanizm of sediment redistribution in their catchments, to identify sediment delivery pathways to the reservoir and their possible changes over different time windows. The drainless Lake Khorlakel, located at the altitude of 2045.0 m above sea level on the northern macroslope of the Greater Caucasus. It is a suitable testing ground for complex research: on the one hand, the relict reservoir is an ideal sedimentation trap, and on the other, it is located with in an area of intensive exogenous processes and tectonic activity. The two boreholes were drilled in 2017 in the deepest (≈8 m) part of the lake and 17 samples collected taken from the cores for radiocarbon dating, which made it possible to build an age model for the range from 8000 to 500 yr. BP. Complex geological and geomorphological studies were carried out in 2021 to interpret the obtained data. It was found that sedimentation in the lake is associated with runoff and sediment redistribution in the Elbashi creek catchment. A number of episodes of proluvial activation with the formation of an outflow cone, followed by lake accumulation, have been traced for the last 8 kyr. The connection between lake and catchment ceased only in the last 1 kyr. BP. Two main stages of lake sedimentation with a boundary of 3 kyr. BP and 10 episodes, that are characterized by different proportions of mineral and organic components in bottom sediments were established. Some of the lithostratigraphic boundaries correlate with strong earthquakes that occurred in the Elbrus region, and some – with climatic events.

The change in sediment yield is an important indicator of the natural environment dynamics, depending on the combination of landscape, tectonic and climatic conditions. Assessment of sediment yield often based on the results of studying the bottom sediments of mountain lakes with relatively compact catchments. However, for correct reconstructions, in addition to analyzing lake sediments, it is necessary to study the causes and mechanizm of sediment redistribution in their catchments, to identify sediment delivery pathways to the reservoir and their possible changes over different time windows. The drainless Lake Khorlakel, located at the altitude of 2045.0 m above sea level on the northern macroslope of the Greater Caucasus. It is a suitable testing ground for complex research: on the one hand, the relict reservoir is an ideal sedimentation trap, and on the other, it is located with in an area of intensive exogenous processes and tectonic activity. The two boreholes were drilled in 2017 in the deepest (≈8 m) part of the lake and 17 samples collected taken from the cores for radiocarbon dating, which made it possible to build an age model for the range from 8000 to 500 yr. BP. Complex geological and geomorphological studies were carried out in 2021 to interpret the obtained data. It was found that sedimentation in the lake is associated with runoff and sediment redistribution in the Elbashi creek catchment. A number of episodes of proluvial activation with the formation of an outflow cone, followed by lake accumulation, have been traced for the last 8 kyr. The connection between lake and catchment ceased only in the last 1 kyr. BP. Two main stages of lake sedimentation with a boundary of 3 kyr. BP and 10 episodes, that are characterized by different proportions of mineral and organic components in bottom sediments were established. Some of the lithostratigraphic boundaries correlate with strong earthquakes that occurred in the Elbrus region, and some – with climatic events.

The newest block-fault structure is revealed, and tectonic deformations exposed in coastal cliffs are studied and systematized as a result of morphotectonic studies on the territory of the Sambian (Kaliningrad) peninsula. The conjugation of multidirectional systems of morpholineaments is established in the morphostructure of the peninsula, defining the “block” tectonics of the peninsula with different roles in relief: (a) sublatitudinal and meridional systems predominate on the flanks, associated with the formation of the Gotland–Baltic graben system; (b) in the axial part of the peninsula, the NW system controlling the main Holocene uplift; (c) in the northeastern part, the NNW system determining the development of the Curonian Lagoon; and (d) in the southwestern part, the NE system setting the master plan of the Vistula depression. Deformations in loose sediments have been studied on the western and northern shores of the peninsula: (a) faults, including normal faults, reverse faults, and thrusts with an amplitude from centimeters to several meters; (b) folds, from micro-folds to gentle synclines with an amplitude of up to meters and a width of up to a few hundred of meters and compressed anticlines; (c) liquefaction, including deformation horizons, local homogenization, intralayer fragmentation, clastic dikes, associated with earthquakes of different strengths. Spatial and chronological relationships between sedimentation and deformations are established, indicating five stages of tectonic activation on the territory of the peninsula: (1) Saale (Moscow) late glacial (weakly active); (2) post-Saale (Moscovian) (maximally active); (3) late-Eemian–pre-Weichselian (Mikulinskii–pre-Valdai) (active); (4) late glacial–early Holocene (weakly active); and (5) late Holocene (weakly active). The most intense tectonic movements were at the post-Saalian (Moscovian) stage: the amplitudes of vertical fault displacements reached the a few tens of meters, and the thickness of the liquefaction horizons exceeded 1 m. At later stages, the intensity decreased, manifested in a decrease in the amplitudes of displacements to a few decimeters at the pre-Weichselian (pre-Valdai) stage and to the first centimeters in the Holocene.

The main research areas of the Laboratory of Geomorphology, Institute of Geography, Russian Academy of Sciences, in the context of global natural and anthropogenic challenges of recent decades, including natural climatic, volcanic, and tectonic changes on the one hand and the total transformation of the Earth's surface by humans on the other hand, are considered. The impact of humans on the geological environment over the past 100 years has reached a level where the traces of human activity have become a geological factor, which has given rise to a new geological stage-the Anthropocene. In geomorphology, the paradigm of relief formation as a counterpoint to endogenous and exogenous processes is changing: it has begun to include the third, anthropogenic, component. The combination of natural and anthropogenic causes contributes to changes in the regime of relief-forming processes, which increasingly have become catastrophic. At the same time, due to new methods and data, the level of understanding of the factors and mechanisms of development of these processes has increased, and the technological possibilities of preventing or minimizing the negative consequences of their manifestation are expanding. This determines the relevant tasks of modern geomorphology, in particular, the areas of activity of the Laboratory of Geomorphology, including the development and use of new methods for studying the relief and relief-forming processes; data analysis; modeling and mapping; study of global, regional, and local trends in relief formation; study of the principles of functioning and design of anthropogenic geomorphological systems; and data synthesis (assessment of geomorphological hazards and risks and geomorphological forecasting).

В данной статье приведены основные результаты исследований по условиям формирования антропосферы на Европейской территории России (ЕТР). Определены факторы, которые этому способствовали. В работе приводятся понятия и выделяются основные типы антропогенного морфолитогенеза

The purpose of this study is to determine a morphologically pronounced fault-block structure identified with the neotectonic stage and compare it with sites with manifested exogenous processes, as well as modern and historical paleoseismicity in order to establish faults activated in the postglacial time. Based on the analysis of space images (Landsat-ETM+) and a digital elevation model (GTOPO-30), the territory of the Kola Peninsula and the adjacent part of North Karelia is subjected to morphostructural interpretation with identifying morpholineaments and an elementary block structure. It is shown by the analyzing the directions and extent of elementary, single (simple), and complex (echeloned, parallel conjugated, and imbricated) linear structures and their zones that both linear (fault) and areal (block) structures are characterized by a predominance of a single system of northwestern and northeastern differences with a clear dominance of the former and unimodal distribution of the extent of faults and the area of blocks, depending on their number. This indicates a single (recent) stage in the formation of the morphotectonic appearance of the territory and no discrete hierarchy of the morphostructures. The degree of fragmentation of the territory at different depths is calculated depending on the number and extent of morpholineaments. It is determined that morpholineaments have a high degree of inheritance from Archean-Proterozoic structures (approximate to 50%). Elementary morphotectonic blocks are grouped into composite blocks bounded by linear zones of great extent (100-600 km) having individual physiognomic features determined by fault patterns, which indicates the nature of the neotectonic dynamics and the degree of inheritance or reformation of the structural plan. The localization of manifestations of exogenous processes, epicenters of paleo-, historical, and modern earthquakes is determined on the basis of the analysis of topographic maps scaled at 1:100,000, catalogs of historical and paleoearthquakes, and the consolidated literature (including the data obtained by the authors of this study) on paleoseismic deformations. A geoinformation base is compiled, which is used to simulate the spatial distribution of endo- and exogenous signs of tectonic activity and compare it with the neotectonic fault-block structure. The spatial similarity of endogenous and exogenous activation zones and their confinement to faults, defined as activated in the postglacial time, are revealed. It is revealed that the following elements are most active in the postglacial-Holocene. First, flank elements on the Kola Peninsula along the Barents Sea coast, the Kandalaksha Bay shores, and the Gorlo Strait of the White Sea. Second, the central (nodal) part with the Khibiny and Lovozero massifs. Third, submeridional (transverse) secant structures separating the eastern part of the peninsula from the western part (Khibiny-Kola and Khibiny-Niva). The spatial parameters of the activated zones indicate a range of earthquake magnitudes M approximate to 6.5-7.5 generated by these structures both in the postglacial period and in the Neopleistocene as a whole.

Аннотация.Представлены результаты палеосейсмогеологических исследований на юго-западе Кольского региона (СВ Фенноскандинавского щита).Изучение различных групп сейсмонарушений в районе детального изучения участка Лувеньгских тундр, а также морфотектонические данные, позволили выделить крупную Имандро-Колвицкую сейсмотектоническую зону, прослеживающуюся от западной части оз.Бабинская Имандра до Колвицкого озера и Умбинской губы

This chapter reviews the results of studies of late- and postglacial faults in the Russian part of the Fennoscandian Shield (Kola Peninsula, Karelia, Sankt-Petersburg region). It provides a brief overview and description from north to south of the main seismic lineaments (Murmansk and Kandalaksha) as well as results from a study of some secondary lineaments, individual late- and postglacial faults and seismic dislocations. The obtained data allowed defining a decrease in seismic activity from the Late Glaciation to the present times. It is due to the fading glacial isostatic uplift of the shield and the change of the leading role from the vertically directed forces of glacial isostasy to horizontal compressive strains. Glacial isostasy as a factor giving rise to stresses has nearly exhausted itself by the present time, while the tectonic factor continues to be felt.

Earthquake-induced deformations located near Murmansk City were investigated for information on the age, tectonic position and spatial occurrence of paleo-earthquakes. The main earthquake-generating zone is identified to be the system of strike slip faults and reverse-oblique faults trending NNW along the Kola River valley. We used radiocarbon analysis and paleogeographic reconstructions and revealed three episodes of increased seismic activity: from 9500 to 10500 cal BP, from 892 to 1182 cal BP, and from 200 to 300 cal BP. Based on the peak ground velocity estimation method we suggest that an earthquakes with a maximum moment magnitude up to Mw ≈ 6.0–6.5 may have taken place in the studied area. The recorded location of seismogenic deformation near faults indicates area of strong Late Glacial and Holocene earthquakes occurring in the northern Kola Peninsula; this is also consistent with observations concerning the historical events of 1772 and 1873, which took place near the area.Combined with previous data on palaeoseismicity in Kola region, our studies indicate a longer lasting and more complex spatial and temporal history of postglacial seismicity in the Northeastern Fennoscandian Shield area. In contrast to the generally accepted opinion, strong seismic events occurred not only during the deglaciation period or immediately after it, but continued until the late Holocene and the last centuries. Glacial isostasy as a factor giving rise to stresses has become minimal by the present time, while the tectonic factor continues to be felt.

—Terraces at four hypsometric levels were studied in the Vuoksa River basin (northern part of the Karelian Isthmus, NW Russia). New data on nine sections of late Quaternary–Holocene sediments have been obtained. Their age has been determined (for the first time for surface deposits in the studied region) in the interval from 90 to 2 ka. The terrace sediments are disturbed by deformations (faults, folds, and liquefaction) caused by six strong earthquakes in that period. The relationships among the terrace levels, ages, stratigraphy, and structures of loose sediments point to their formation under the impact of differentiated tectonic motions triggered by the activation of the ancient “Vuoksa” fault zone in the late Neopleistocene and Holocene.