|Holocene Kamchatka volcanoes||
Institute of Volcanology and Seismology
Kamchatka volcanoes during the last 10,000 years
viewed by tephrochronologists
Kamchatka Peninsula is one of the most precious gems in the Pacific "Ring of Fire". Kamchatka hosts about 30 recently active volcanoes and hundreds of monogenetic vents, which form a 700-km long volcanic belt from Shiveluch in the north to Kambalny in the south. Kamchatka's vigorous volcanism as well as that of adjacent Aleutian and Kurile island arcs is produced by subduction of the Pacific plate.
The last scientific book on Kamchatka volcanoes, a sort of catalogue (Fedotov and Masurenkov, eds), published in 1991, is based mostly on works done during 1970s and 1980s. Moreover, many Holocene volcanoes, including such important vents as Kurile Lake caldera, Khodutka, Taunshits or Khangar, were not included into this book. So there is a necessity to provide a new compilation on Kamchatka volcanoes.
We, a team of researchers from Institute of Volcanology and Seismology (IVS, Kamchatka) and Geological Institute (GIN, Moscow), have been studying the eruptive histories of Kamchatka volcanoes for many years. We decided to compile our recent papers and abstracts on Holocene volcanoes of Kamchatka, complement them with some new unpublished data, and to make this site in order to share our excitement and experience with those who will come to study Kamchatka in near future. Our goal now is not to provide a formal catalogue of the Holocene Kamchatka volcanoes but rather just to show them and some of their deposits, to point out their puzzles and interesting features, and to provide for each volcano a list of references available in English.
Main contributors: Olga Braitseva, Vera Ponomareva, Ivan Melekestsev (IVS); Leopold Sulerzhitsky, Maria Pevzner (GIN). Photos by Leopold Sulerzhitsky, Vera Ponomareva, Maria Pevzner, Nikolai Smelov, Philip Kyle, Andrei Nechaev, Philippe Bourseiller, Alexey Tsyurupa, Vasili Podtabachnyi, Adam Kirilenko, Viktor Dvigalo, Joanne Bourgeois, Oleg Dirksen, Sergei Konyaev.
The site was designed by Alexey Tsyurupa. We are grateful to Maksim Stolyarov who scanned many of the images and maintained our computers.
The Kamchatka arc is one of the most active seismic and volcanic regions in the world (e.g. Gorbatov et al., 1997). It hosts about 30 recently active volcanoes and hundreds of monogenetic vents, which form a 700-km long volcanic belt from Shiveluch in the north to Kambalny in the south. The subduction of the old, cold Pacific plate below Kamchatka at a rate of 9-10 cm/yr (Minster and Jordan, 1978; Geist and Scholl, 1994) is the primary source of extensive magma-genesis and can account for most volcanism along the arc.
Volcanoes in Kamchatka are traditionally combined into three groups: Central Kamchatka depression, Sredinny range, and Eastern volcanic belt, the latter including Eastern Kamchatka, Avacha river basin and South Kamchatka zones (a map).
I. Central Kamchatka depression volcanoes, including Kliuchevskoi group and Shiveluch, represent a departure from other Kamchatka arc volcanoes in terms of their geographic, tectonic and geological significance possibly related to tectonic evolution of the Kamchatka-Aleutian junction (Yogodzinski et al., 2001). Kliuchevskoi and nearby Bezymianny are the largest and most prolific of Kamchatka volcanoes, exhibiting the highest magma flux of the entire Pacific Rim (Fedotov & Masurenkov, 1991). Growing at about 500m/1000 ys, Kliuchevskoi erupts at least once every decade. Another 10 volcanoes of the Kliuchevskoi group demonstrate a large variety of magma compositions, some of which are not observed anywhere else in Kamchatka.
II. Sredinny Range volcanism is regarded either as a back-arc feature associated with the modern subduction zone (in spite of an apparently non-extensional tectonic environment) (e.g. Churikova et al., 2001) or as an individual volcanic arc related to an ancient subduction zone (Avdeiko et al., 2001, 2002).
III-V. The Eastern volcanic belt, stretching parallel to the trench, usually is regarded as a frontal subduction-related volcanic arc. However, the belt is unusually wide, its inner structure is rather complicated, and some volcanoes are located far to the west from the main arc (a map). Some of the volcanic vents form a separate groups like Avacha river basin volcanoes.
In the Mediterranean or other long-inhabited regions, a story of volcanic eruptions, earthquakes, floods, for the last 4,000 years is written in historical records or at least saved in local legends. In Kamchatka, the historical record dates back for only a couple of centuries; that is why the only way to learn about older geologic events and environmental changes caused by them is to conduct field work searching for deposits and landforms left by these past events.
Volcanism in the Kurile-Kamchatka region is highly explosive. Multiple Holocene ash layers separated by soils or sandy loams or peat form a soil-pyroclastic cover, which blankets most of Kamchatka. It is a few tens of centimeters thick in the areas distant from the active volcanoes and increases up to several meters at their foot (Photo). This cover provides a continuous record of explosive eruptions during the last 10,000 years.
During deposition, the ash from a larger eruption instantaneously "seals" vast areas and thus becomes a wonderful stratigraphic marker, which allows correlation of distant deposits. Ashes from the largest Kamchatka eruptions can be traced as far as about 1000 km from the source. It is an intriguing and captivating work to trace an ash downwind away from the source volcano and watch it continuously changing in grain size, thickness, color and other features. These changes may mean that it is not feasible to recognize a certain ash layer in distant outcrops without direct tracing from one outcrop to the other. To avoid this huge work and confirm the correlations we need to fingerprint each ash layer geochemically that is to find a set of geochemical features characteristic of this specific ash, which will allow any researcher to identify it in a remote section.
Holocene deposits provide a continuous record of the events since the last major glaciation up to today, that is for about 10,000 years. Volcanic eruptions, earthquakes, tsunami, floods, ancient human activity, even forest fires leave evidence in the geological record. We live in the Holocene, so the study of Holocene deposits provides a necessary background for understanding modern processes. Using dated marker ash layers we can correlate distant outcrops and see what happened at any certain time in various places, and learn the types and scale of past natural hazards.
Our work is basically tephrochronology - we dig pits or clean natural outcrops, containing numerous ash layers from different volcanoes, and measure and describe them. Then we sample ash layers for their geochemical identification and sample intercalated organic-bearing horizons to radiocarbon date the latter, and with their help, to assign ages to ash layers. As a result, we get a detailed timescale, and with the help of identified marker ash layers we then can date various volcanic (lava and pyroclastic flows, cinder cones etc) and non-volcanic (river and marine terraces, tsunami deposits etc.) landforms and deposits, and in this way, produce detailed records of various geologic events. Tephra layers formed by the most voluminous explosive eruptions are the best markers.
With the help of these markers we have studied the eruptive histories of most Kamchatka volcanoes. The studies of each volcano have included:
We gratefully acknowledge the support from the following organizations: Institute of Volcanic Geology and Geochemistry, Kamchatka; Geological Institute, Moscow; NATO-Russia Cooperative Program. Some of the recent photos has been taken during field expeditions funded by the Russian Foundation for Basic Research, National Geographic Society (USA), National Science Foundation (USA). We cordially thank all our sponsors .
Avdeiko GP, Popruzhenko SV, Palueva AA. (2002) The Tectonic Evolution and Volcano-Tectonic Zonation of the Kuril-Kamchatka Island-Arc System. Geotectonics 36 (4), 312-327
Avdeiko GP, Popruzhenko SV, Palueva AA ( 2001) "Modern structure of the Kurile-Kamchatka region and magma-forming conditions". In: Geodynamics and volcanism of the Kurile-Kamchatka island arc system. IVGG FEB RAS, 9-33 (in Russian).
Bindeman IN, Ponomareva VV, Bailey JC, and Valley JW (2004) Kamchatka Peninsula: a province with high-d18O magma sources and large 18O/16O depletion of the upper crust. Geochimica et Cosmochimica Acta 68/4: 841–865
Braitseva OA, Sulerzhitsky LD, Litasova SN, Melekestsev IV, Ponomareva VV (1993) Radiocarbon dating and tephrochronology in Kamchatka. Radiocarbon 35/3: 463-476
Braitseva OA, Melekestsev IV, Ponomareva VV, Sulerzhitsky LD (1995) The ages of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region, Russia. Bull Volcanol 57 (6): 383-402
Braitseva OA, Ponomareva VV, Sulerzhitsky LD, Melekestsev IV, Bailey J (1997a) Holocene key-marker tephra layers in Kamchatka, Russia. Quaternary Research 47/2: 125-139
Braitseva OA, Sulerzhitsky LD, Ponomareva VV, Melekestsev IV (1997b) Geochronology of the greatest Holocene explosive eruptions in Kamchatka and their imprint on the Greenland glacier shield. Transactions (Doklady) of the Russian Academy of Sciences. Earth science sections. 352/1: 138-140
Churikova T., Dorendorf F., Woerner G. (2001) Sources and fluids in the mantle Wedge below Kamchatka, Evidence from across-arc geochemical variation. Journal of petrology, 42/8: 1567-1593
Davies J.H. (2002) Breaking plates. Nature 418, 15 August, 736-737
Fedotov SA, Masurenkov YuP (eds) (1991) Active volcanoes of Kamchatka. Nauka, Moscow. Vol.1, 302 p. Vol.2, 415 p.
Florensky IV, Trifonov VG. 1985. Active tectonics and volcanism of the Eastern volcanic belt in Kamchatka. Geotectonics. No.4: 78-87 (in Russian).
Geist EL, Scholl DW (1994) Large-scale deformation related to the collision of the Aleutian Arc with Kamchatka. Tectonics 13: 538-560
Gorbatov A, Kostoglodov V, Suarez G, Gordeev EI (1997) Seismicity and structure of the Kamchatka subduction zone. J Geophys Res, B, 102(8): 17,883-17,898
Gusev AA, Ponomareva VV, Braitseva OA, Melekestsev IV, and Sulerzhitsky LD (2003) Great explosive eruptions on Kamchatka during the last 10,000 years: self-similar irregularity of the output of volcanic products. J Geophys Res 108/B2: 2126, doi:10.1029/2001JB000312
Melekestsev IV, Braitseva OA, Ponomareva VV (1989) Prediction of volcanic hazards on the basis of the study of dynamics of volcanic activity, Kamchatka. In: Volcanic Hazards Assessment and Monitoring: IAVCEI Proceedings in volcanology I. Berlin - ...Tokyo. Springer-Verlag, pp. 10-35
Simkin T, Siebert L (1994) Volcanoes of the World. Second edition. Geoscience Press, inc. Tucson, Arizona.
Vlodavets VI (ed) (1957) Catalogue of the active volcanoes of the USSR. Bull volcanol stancii 25, 180 p (in Russian)
Volynets O.N. 1994. Geochemical types, petrology and genesis of Late Cenozoic volcanic rocks from the Kurile-Kamchatka island-arc system, International Geological Review 36/4, 373-405.
Yogodzinski GM, Lees JM, Churikova TG, Dorendorf F, Wörner G, Volynets ON (2001) Geochemical evidence for the melting of subducting oceanic lithosphere at plate edges. Nature, vol.409, 25 January, 500-504.