Identification of ionospheric earthquake precursors in Kamchatka region based on correlation analysis

Сейсмическая активность является одним из источников изменчивости ионосферы. В данной работе на основе методики [1] исследовано изменение концентрации электронов в ионосфере, предшествующее наступлению сильных землетрясений с M ≥ 6.0 в Камчатском регионе. Данная методика основана на вычислении коэффициента корреляции между значениями критической частоты foF2 двух ионосферных станций, одна из которых расположена внутри зоны подготовки землетрясения, а другая – за ее пределами. Рассмотрены данные, полученные на двух станциях PETROPAVLOVSK (PK553) и EARECKSON (EA653) за период 01.09.2018–30.04.2021 гг. Статистический анализ критических частот foF2 показал, что для 6 из 8 землетрясений с M ≥ 6.0, произошедших на глубинах до 100 км и эпицентральных расстояниях до 500 км от расположения PK553, за 1–12 суток до их наступления предшествовало заметное уменьшение коэффициента корреляции. Seismic activity is one of the sources of ionospheric variability. In this work, we investigate electron concentration change in the ionosphere, preceding the onset of strong earthquakes with M ≥ 6.0 in Kamchatka region. The research technique is based on calculating the correlation coefficient between the critical frequency foF2 values at two ionospheric stations. One of them is located inside the earthquake preparation zone, and the other is outside it. The data obtained at two stations PETROPAVLOVSK (PK553) and EARECKSON (EA653) for the period 01.09.2018–30.04.2021 are considered. Statistical analysis of the critical frequencies foF2 showed that a noticeable decrease in the correlation coefficient was observed 1–7 days before the earthquakes for 6 out of 8 events with M ≥ 6.0 that occurred at depths of up to 100 km and epicentral distances of up to 500 km from the PK553 location.

Accumulative landforms in valleys with gas-hydrothermal manifestations of the Kuril-Kamchatka region

Within the watercourse valleys of geothermal zones, where manifestations of gas-hydrothermal activity are noted, the processes of relief formation are accompanied by chemical and thermal effects. Thermal waters contribute to the formation of specific accumulative landforms both directly in the channel and in the bottom and on the sides of river valleys. Similar phenomena have been studied in river valleys draining the slopes of the Mendeleev volcano (Kunashir Island), Baransky volcano (Iturup Island), Mutnovsky volcano and Uzon-Geyzernaya caldera (Kamchatka). The typification of accumulative relief forms is carried out, the influence of gas-hydrothermal manifestations on fluvial and slope processes is determined.

Redescription of two rare, deep-sea species of hyperiidean amphipod, Lanceola loveni antarctica Vinogradov, 1962 and L. sphaerica Vinogradov, 1970 (Crustacea: Amphipoda: Hyperiidea: Lanceolidae)

Lanceola loveni antarctica and L. sphaerica are rare deep-sea species known from very few specimens. Until recently (Zeidler 2019) L. loveni antarctica was known only from the types, seven specimens (7–27 mm), from the Indian Ocean Sector of the Antarctic (Vinogradov 1962). Similarly, L. sphaerica, originally described as a variety of L. clausi (Vinogradov, 1957), based on two damaged specimens, a female (8.0 mm) and a male (9 mm), from the Kurile-Kamchatka region of the NW Pacific, later elevated to full species status by Vinogradov (1970) upon the discovery of a well-preserved male (5 mm) from the same general region, was until then known only from these three specimens. The recent discovery of several specimens of both species in the USNM (Zeidler 2019) has now made it possible to provide a more detailed redescription of these rare species, including some new distribution records.

Comparison of estimates parameters of earthquakes in the Kamchatka region from different catalogs

Для землетрясений Камчатского региона и землетрясений в районе западной части Алеутско – Командорского желоба рассчитаны невязки между временем пробега волн P исходя из оценки времени в очаге и временем пробега в соответствии с моделью Земли AK135. Выявлено систематическое расхождение значений времен пробега, полученных этими способами, причем величина невязки меняется в зависимости от применяемого метода оценки параметров гипоцентров. Результаты сравнения отражают реальную оценку точности координат гипоцентров в каталогах. Проверка качества привязки сейсмических трасс к точному времени показало наличие сбоев синхронизации на сейсмограммах почти всех комплектов сейсмографов, что может быть одной из причин невязок. he article presents the results of work with such devices as the digital engineering seismic station «TELSS — 3» (LLC «Geosignal»), complete with seismic streamer SM — 20 and seismic receivers GS — 20 DX in order to clarify soil conditions in the valley of the Avacha river in Yelizovsky urban district. The method of refracted waves of seismic exploration was performed for the first time. It is important to note the importance of the seismic station for obtaining primary acoustic data for further refinement of seismic increments. Thanks to the data obtained, it becomes possible to make the right decisions when designing construction objects.

Review of the book: Gavrilov S.V. Representative authority of Kamchatka (1917–1977)(1977–1993).

In the proposed review of scientific research, set out in 2 books, in a chronological framework: 1917–1977. and 1977–1993, the analysis of social technologies associated with the forms of organization of councils as state authorities, its political basis in the USSR / Russia, their capabilities, which had transformations during the periods of their formation and development, as well as other types – executive committees, revolutionary committees (revolutionary committees). The process of the emergence of the system of these authorities on the territory of the Kamchatka province / region is considered. The attitude of the researcher to the study of aspects of the topic is shown. His knowledge of both the essence of the existing assessments of their role, and the contribution to the development of the system itself. The content of directions for improving the management and regulation of social processes is analyzed. Attention is drawn to the direction of solutions to the problems of strengthening statehood, achieving effective activity of structural units, from lower to higher authorities. The author identified about 2000 portraits of political and public figures, representatives of this system in the Kamchatka region, disclosed the forms and methods of their work in different areas of management, development of the community of peoples on the territory of the multinational region. Materials and methods. In the writing of a review, the appeal to such methods as historical-genetic, historical-comparative, historical-typological, which allows, in aggregate, to trace the differences of the process, events that reflect the essence of the phenomenon that characterize the interaction, prevails. Along with this, a comparison of the processes of development of society and the management system at different stages of the period under study in 1917–1977, the military situation on the eve of the war, the war period of 1941–1945, post-war reconstruction, 1977–1993, the degree of generalization by the author of the material presented, revealing by him the essence of the transformations that took place. It is also obvious that there was every reason for attracting the prosopographic method of research, which allows not only to fully cognize the person (who represents power), but also to show the background of events. As for the materials directly, http://www.hist-edu.ru Историческая и социально-образовательная мысль. Toм 13 №2, 2021 Historical and Social-Educational Idea. Volume 13 #2, 2021 295 the researcher evaluates those that are used by him in the narrative – "living sources" (archival documents, press, memoirs) Due to the lack of analysis of the historiography of the problem under study, it is possible to present not only an assessment of the work done by the author. They mention, with rare exceptions, for example, the works of the famous writer of the Kamchatka Territory A.A. Smyshlyaev, as well as a collection of documents. The author identifies in the course of his work a large corps of workers' deputies employed in the past or in modern conditions in the work of government bodies (since 1917), of whom about 2 thousand people are mentioned.

Modeling of convective heat-mass transfer in permeable parts of seismic focal zones of the Kamchatka region and associated volcanic arcs

<p>The paper presents a non-isothermal model of hydrodynamic heating of lithospheric rocks above magma chambers in application to the seismic focal zone of the Kamchatka region and associated volcanic arcs. The effect of convective heating of mantle and crustal rocks on dynamics of metasomatic changes and convective melting was studied. In the existing models of ore-forming systems, fluid mass transfer is determined mainly by the retrograde boiling of magmas in meso-abyssal intrusive chambers. Analysis of the manifestations of deposits of the porphyry formation of the Pacific Ocean active margins shows the decisive participation in their formation of mantle-crust ore-igneous systems. The model of convective heat-mass transfer in fluid mantle-crust systems coupled with magma chambers is designed with the consideration of effects of interphase interaction in rocks of permeable zones above igneous fluid sources. Numerical simulation of the dynamics of fluid systems under the volcanoes of the frontal zone of Kamchatka shows altered ultramafic rocks in metasomatic zoning and the presence of facial changes in the mineral composition of wehrlitized rocks. In the mantle wedge of the northwestern margin of the Pacific Ocean, over which epicontinental volcanic arcs developed in the post-Miocene stage, there is possible combination of the products of different-time and different-level igneous systems in the same permeable "earth's crust-lithospheric mantle" transition zones. Assuming that the "cratonization" of volcanic sections of the continental Earth's crust follows the "metasomatic granitization" pattern, the initial element of which is the wehrlitization of mantle wedge ultramafic rocks, the processes of metasomatic fertilization of mantle wedge rocks were investigated using a flow-through multiple-reservoir reactor. In the seismically active regions of the Pacific transition lithosphere, specific conditions for heating of areas of increased permeability above mantle fluid sources should be recorded. Metasomatic columns in such fluid systems can describe the formation of at least three levels of convective melting of metasomatized mantle wedge substrates, as well as the formation of a region of high-temperature fluid change of mafic intrusion rocks in the Earth's crust. The work was financially supported by the Russian Foundation for Basic Research, grants No. 19-05-00788.</p>

Surface manifestations of short-period internal waves of the Kuril-Kamchatka region and the Bering Sea according to satellite observations

<p>In the Bering Sea, as in the Kuril-Kamchatka region, which includes the waters near the Kuril Islands and the Pacific waters of the Kamchatka Peninsula, previously performed satellite radar observations show numerous scattered surface manifestations of short-period internal waves (SIW’s). However, the summative study of the characteristics of surface manifestations of SIW’s are currently not available in this region.</p><p>In this study, radar images from the Sentinel-1A and B satellites from July 1, 2019 to September 30, 2019 were used to record the surface manifestations of SIW’s. For each surface manifestation of SIW’s, such characteristics as the position of the manifestation, the wavelength, the arc length of the leading ridge in the packet, the direction of propagation, and the number of waves in the packet are determined. Wave detection on the radar images is performed using ESA SNAP and Matlab software.</p><p>In the study region, 1,540 SIW’s. manifestations with a wavelength of 80 to 1,900 meters and a leading crest length of 1 to 70 km were registered on 772 radar images. The ranges of variability of the main geometric characteristics of the manifestations in the Kuril-Kamchatka region and in the Bering Sea are very similar. The maximum number of manifestations in the Kuril-Kamchatka region was recorded in the first half of September, and in the Bering Sea – in the second half of July. This difference seems to be related to regional features of pycnocline formation.</p><p>Manifestations of internal waves are mainly recorded in the shelf zone. The constant occurrence of manifestations of internal waves located in the southern part of the Kuril Islands, around the Pacific coast of the Kamchatka Peninsula, East of the Litke Strait, and the Straits of the Aleutian chain. It was found that the areas of constant occurrence of the manifestations of SIW’s coincide with the areas of intense dissipation of the internal tide. In the Kuril-Kamchatka region, in contrast to the Bering Sea, manifestations of internal waves are recorded over significant depths at a great distance from the shelf zone, which is associated with the collapse of the internal tide reflected from the edge of the continental slope.</p><p>The information obtained in this study will allow us to improve our understanding of the field of short-period internal waves of the north-eastern Pacific Ocean.</p><p>The study of surface manifestations of internal waves in the Kuril-Kamchatka region was supported by RFBR grant No. 20-35-90054. The study of surface manifestations of internal waves in the Bering Sea was supported by RFBR grant No. 18-35-20078.</p>