No 3 (2019)

New data on age, material composition and geological structure of the Central Kamchatka depression (CKD). Part 1. Rocks types. Age, petrological and isotopo-geochemical characteristicsн
Koloskov A.V., Davydova M.Y., Kovalenko D.V., Ananyev V.V.
Abstract

The paper presents new age and isotope geochemical characteristics for plateau effusive rocks from the Central Kamchatka Depression (CKD) and Nikolka Volcano. We compared these data with the data on rocks from the Klyuchevskoy group of volcanoes and also Sheveluch, Kharchinsky, Zarechny, Nachikinsky, Bakening volcanoes and NEB-adakites from Pliocene shield volcano between the Ozernaya Kamchatka and Pravaya Kamchatka rivers. It is shown that the evolutionally advanced (often more alkaline) rock from Nachikinsky, Bakening, Nikolka volcanoes and the Pliocene shield volcanoe significantly differ in isotope-geochemical characteristics from the Klyuchevskoy group of volcanoes rocks. Exactly this type of rocks is characteristic for CKD as rift structure. The Klyuchevskoy group of volcanoes rock are not typomorphic for this structure and manifest the usual orogenic volcanism stage, typical for much larger area. Miocene plateau effusive rocks differ from rocks of this group only by slightly increased potassium alkalinity. The rift type rocks characteristic feature is not only their increased alkalinity, but also specific microcomponents ratios: Ti/V > 0.004, Nb/Y > 0.28, Dy/Yb > 2.00, La/Yb > 6.5, Sm/Yb > 2.4, Lu/Hf < 0.08. Along with isotopic characteristics, these ratios suggest the existence of the single deep asthenospheric mantle reservoir for initial melts. The Kurile-Kamchatka and Commander-Aleutian island-arc systems’ junction is marked by the increased fluid enrichment (Ce group of REE) of melts for rocks of certain volcanoes: Shiveluch, Kharchinsky, Zarechny.

Вулканология и сейсмология. 2019;(3):3-24
views
Volcanism and geochemistry of soil and vegetation cover of Kamchatka. Communication 2. Specificity of forming the elemental composition of volcanic soil in cold and humid conditions
Zakharikhina L.V., Litvinenko Y.S.
Abstract

Volcanic soils of Kamchatka have the low contents of most the chemical elements in relation to their overall prevalence in the soils of continents and volcanic soils of Europe. Relatively increased gross contents of elements typical for volcanic rocks of medium and basic composition: Na, Ca, Mg, Cd, Mn, Co, Cu, and steadily low contents of elements characteristic of acid volcanics: La, Ce, Pr, Nd, Nb, Hf, Tl, Rb and Th, is most characteristic of the soils of different areas of the peninsula. The existing in the past and currently observed different conditions of volcanism in the previously allocated soil areas of Kamchatka determine the diversity of the chemical composition of the soils in these territories.

Вулканология и сейсмология. 2019;(3):25-33
views
2016 volcano eruptions in Kamchatka and the Northern Kuriles and their danger to aviation
Girina O.A., Manevich A.G., Melnikov D.V., Nuzhdaev A.A., Petrova E.G.
Abstract

Strong explosive volcanic eruptions are extremely dangerous to the modern jet aircraft as they can produce several cubic kilometers of volcanic ash and aerosols that can be sent to the atmosphere and the stratosphere in several hours to several days during the eruption. In 2016, five from thirty active volcanoes erupted in Kamchatka (Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Zhupanovsky) and three from six active volcanoes in the Northern Kuriles (Alaid, Ebeko, and Chikurachki). Effusive volcanic activity was noted at Sheveluch, Klyuchevskoy, Bezymianny and Alaid. All the volcanoes produced explosive activity. Strong explosive events occurred at Sheveluch mainly from September till December. Moderate ash emission had accompanied of Klyuchevskoy’s eruption through March till November. Explosive activity at Karymsky, Zhupanovsky, Alaid, and Chikurachki volcanoes was observed mainly in the first half of the year. The total area covered by ash in 2016 was estimated 600,000 km2, from which 460,000 km2 were related to the eruptions of Kamchatka volcanoes and 140,000 km2 were attributed to the eruption of the North Kuriles volcanoes. The activity at Sheveluch, Klyuchevskoy, and Zhupanovsky was dangerous to international and local airlines as explosions produced ash up to 10-12 km above sea level. The activity at Bezymianny, Karymsky, Alaid, Ebeko, and Chikurachki posed a threat to local aircrafts when explosions sent ash up to 5 km above sea level.

Вулканология и сейсмология. 2019;(3):34-48
views
Electric charging of eruptive clouds from Shiveluch Volcano caused by different types of explosions
Firstov P.P., Akbashev R.R., Zharinov N.A., Maximov A.P., Manevich T.M., Melnikov D.V.
Abstract

The number of explosive eruptions at Shiveluch Volcano has significantly increased over the past years, which requires close volcanic monitoring using all available techniques. In order to implement a new monitoring technique into integrated methods of volcano monitoring, the authors analyze response to the intensity of the vertical component in the atmospheric electrical field (EZ AEF) during the movement of ash clouds. Two eruptions of different intensity that occurred December 16, 2016 and June 14, 2017 at Shiveluch were selected for study. We used a combination of satellite, seismic, and infrasound data to select signals in the EZ AEF field. Signals with negative polarity that accompanied ashfalls in the EZ AEF dynamics were registered for both eruptions within the closest area (< 50 km). In the former case, the ash cloud was “dry” and thus it caused aerial-electrical structure of the negatively charged cloud. In the latter case, a strong explosion sent into the atmosphere the large volume of ash and volcanic gases (98% in form of vapour) that resulted in the formation of a dipolar aerial-electrical structure caused by eolian differentiation within the closest area. At the distance of more than 100 km we registered a positive-going signal that is attributive to the aerial-electrical structure of the positively charged type of the cloud.

Вулканология и сейсмология. 2019;(3):49-62
views
Modern displacement of active faults in South-Yakutian coal-bearing depression on the GPS data
Imaev V.S., Imaeva L.P., Аshurkov S.V., Grib N.N., Kolodeznikov I.I.
Abstract

For a quantitative assessment of the current horizontal velocity of the surface displacement of the crust in southern Yakutia in recent years, was organized the first and only points of permanent GPS observations in the city of Neryungri (NRG) and the city of Chulman (CHL3). Both points of observation are located within the southern margin of the Eurasian plate, near the system of active structures separating it from the Amur plate.

To estimate the relative displacement, the period of joint operation of these two GPS points was chosen, namely from June 29, 2015 to December 1, 2016. The rate of displacement of the point in Neryungri, calculated for a 5-year period (from 27.10.2011 to 01.10.2016), was 21.83±0.73 mm/year in the East-West direction and 12.26±0.25 mm/year in the North-South direction in the international reference basis ITRF2014. The obtained values differ slightly from the theoretical values of the velocity of the Eurasian lithospheric plate at the specified point. The difference of the measured velocities with velocities according to the known kinematic model of the Eurasian plate obtained in this paper is |0.5| mm/year for the Eastern component and |1.0| mm/year for the Northern one and corresponds to the assessment of other authors [Kreemer et al., 2014]. To improve the accuracy of determining the speed of horizontal displacements of the earth's crust at the station CHL3, it is necessary to continue measurements synchronous with the station NRG2.

Вулканология и сейсмология. 2019;(3):63-71
views
Seismic-strain and acoustic monitoring of geodynamical processes by high sensitive and spatially distanced instruments in seismo-energy-active and aseismic zones
Aleksandrov D.V., Dubrov M.N., Larionov I.A., Marapulets Y.V., Shevtsov B.M.
Abstract

The results of wideband geophysical processes observations by means of laser strainmeters and special geo-acoustic equipment are presented. The examples of synchronous registering of strain-seismic and geo-acoustic earth oscillations in Kamchatka and Moscow region as well as parallel analysis of the obtained data are shown. These results reveal the possibility of the introduced technics application for local and global disturbances of investigated processes separation.

Вулканология и сейсмология. 2019;(3):72-80
views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies