Zelenski M., Simakin A., Taran Yu., Kamenetsky V.S., Malik N.A. Partitioning of elements between high-temperature, low-density aqueous ﬂuid and silicate melt as derived from volcanic gas geochemistry // Geochimica et Cosmochimica Acta. 2021. Vol. 295. P. 112-134. https://doi.org/10.1016/j.gca.2020.12.011.
By comparing high-quality volcanic gas and whole rock compositions, we calculated the apparent (observed) mass partition coeﬃcients Kd* for 58 elements on six basaltic volcanoes located in arc and rift/hotspot settings. The inferred Kd* vary from � 1100 for sulfur to 0.0001 for zirconium, i.e., within seven orders of magnitude. Only 14 elements have Kd* > 1, including highly volatile S, Se, Te and halogens, as well as Tl, Re, Os, Bi, Cd, Au, In and As. Alkali metals have Kd* in the rangefrom 0.1 for Cs to 0.01 for Na. Partition coeﬃcients of other rock-forming elements are <0.001. The partition coeﬃcients for elements depend on element speciation and concentrations of ligand-forming elements in the gas such as sulfur and chlorine.
Elements transported in the gas predominantly as halides have higher partition coeﬃcients in HCl-rich arc gases, whereas elements preferably forming sulﬁdes, hydrides and free atoms, have higher Kd* in sulfur-rich, HCl-poor and reduced rift/hot-spot gases. Degassing directly from the free melt surface is negligible; deep gas passing through the erupting vent is quickly overwhelmed by the signal of low-pressure degassing. Equilibration of rising bubbles with the surrounding melt almost eliminates the diﬀerence between Kd* calculated for degassing lava ﬂows (no connection with deep magma) and for lava lakes and open-vent volcanoes (convective mass exchange with deep magma takes place). Diﬀusion does not strongly aﬀect the apparent partitioning of magmas degassing at surface. Gas bubbles growing in near-surface silicate melts at atmospheric pressure have a large density diﬀerence compared to the surrounding melt of 12–15 thousand times. This leads to the rapid expansion of such bubbles and a decrease in the thickness of the diﬀusion boundary layer in the melt due to its stretching around the growing bubble, which sharply decreases diﬀusion fractionation. As a result, the apparent partition coeﬃcients (Kd*) for degassing basaltic volcanoes are close to the equilibrium ones (Kd) for most of the elements. The partition coeﬃcients of volatile elements (S and Cl) calculated from the comparison of volcanic gas and rock compositions are in agreement with the values determined previously via experiments or theoretical modeling.
Zharinov N.A., Fedotov S.A., Gorelchik V.I. A Model for Klyuchevskoy Volcano Activity from Geodelical and Seismological Data // Kagoshima International Conference on Volcanoes: Proceedings of the International Conference on Volcanoes, Japan, Kagoshima, 19-23 July 1988. Kagoshima: Kagoshima Prefectural Government. 1988. P. 71-74.
Zharinov N.A., Gorelchik V.I., Belousov A.B., Belousova M.G., Garbuzova V.T., Demyanchuk Yu.V., Zhdanova E.Yu. Volcanic eruptions and seismic activity at Klyuchevskoi, Bezymiannyi and Shiveluch in 1986-1987 // Volcanology and Seismology. 1991. Vol. 12. Vol. 3. P. 327-345.
Zharinov N.A., Gorelchik V.I., Zhdanova E.Yu., Andreev V.N., Belousov A.B., Belousova M.G., Gavrilenko V.A., Garbuzova V.T., Demyanchuk Yu.V., Khanzutin V.P. The Eruptions of the Northern Group of Volcanoes on Kamchatka in 1988-1989: Seismological and Geodesic Data // Volcanology and Seismology. 1993. Vol. 13. Vol. 6. P. 649-681.
Zubin M.I., Melekestsev I.V., Tarakanovsky A.A., Erlich E.N. Quaternary Calderas of Kamchatka // International Association of Volcanology and Chemistry of the Earth`s Interior. Sumposium on Volcanoes &Their Roots. Oxford: 1969. P. 111-113.
Zubov A.G., Ananyev V.V. Testing of the Titanomagnetite Method to Detect Magmatic Chamber Depth at Avachinsky Stratovolcano and Tolbachik Fissure Eruption // 10th International Conference “PROBLEMS OF GEOCOSMOS”. Book of Abstracts. St. Petersburg, Petrodvorets, October 6-10, 2014. St. Peterburg: Физфак СПбГУ. 2014. P. 81
Two volcanoes were tested using the titanomagnetite method in order to detect the magma chamber depth. Curie temperature of andesite tephra shows that the magmatic chamber was situated on the depth of 18±7 km under Avachinsky Volcano ~5 Ka ago, but one of the basalt-andesite tephra from Avachinsky results the chamber depth of 32±6 km ~3 Ka ago. This method applied to the lava from Tolbachik Fissure Eruption (TFE) shows a chamber depth of 47±5 km. This result is inconsistent slightly with the depth of 35±6 km obtained by our microzond analysing of element composition of titanomagnetite grains into lava sample from earlier phase of the same eruption. This two different results between TFE lava samples may occur from magma differentiation or this is a methodical or occasional error. To know true it needs a sample statistics. At present, more microzond data from Tolbachik Fissure Eruption are being analyzed.
Абдурахманов А.И., Злобин Т.К., Мархинин Е.К., Тараканов Р.З. Извержение вулкана Иван Грозный в 1989 г. // Вулканология и сейсмология. 1990. № 4. С. 3-9.
Recent activity of the volcano is associated with its multiaction central effusion dome. The N—N—E top of this dome has a crater of the specific shape with a radial fissure 250—270 m long and 15—70 m wide. Small phreatic eruptions were noted in 1951, 1968, 1970, and 1973. The eruption of 1989 started on May 3. Explosions produced ash-gas cloud which rose to a height of 1,5 km on May 8. The very first explosions were followed by formation of a new fissure on the northern flank of the volcano, its length being about 70 m. The eruption was preceded by earthquakes which occurred beneath the volcano and were oriented across the strike of the Kuril Island arc. These earthquakes can be subdivided into two groups with focal depths close to 30 km and 60— 80 km. The layer between the depths from 30 to 55—60 km seems to be aseismic indicating that in the depth range of 30—60 km beneath the volcano a magma chamber can be present. It is suggested that current intensified activity of the volcano has been caused by tectonic movements associated with transverse faulting. A sort-term forecast of the volcano activity is presented.