Repost: Klyuchevskoy (and a coda)

Here, with some editing, is the last of my “stone-torch” reposts from 2020 on Kamchatka volcanoes. There are many, many more fire mountains there than these six (also counting those we’ve covered earlier:
Avachinsky, Koryaksky
, Bezymianny, Kamen and Tolbachik), but Klyuchevskoy, the tallest active volcano in Eurasia, is Kamchatka’s “Big Heat” — all 270 km3 of it. (Ponomareva et al., 2007)

Kamchatka’s First People worship this volcano as the place where Earth was made.

In a sense, they’re right.

Klyuchevskoy probably does tap into a global layer of primal material.

Multiscale 3D seismic tomography studies of Klyuchevskoy show an almost 20-mile-long vertical “pipe” underneath the volcano that reaches down to our planet’s crust-mantle boundary. (Kayzar et al.; Koulakov et al.; in addition, this paper, published in February 2022)

That mantle is the ultimate source of all material in Earth’s rocky crust, from basalt seafloor to granitic continents to the frozen hot-spot lavas that underlie cities like Honolulu and Reykjavik.

Of course the geological situation down there must be more complicated than a simple pipe-like opening from mantle to vent, or else there would be a blowout and Earth’s surface would look very different (also, we’d probably all be dead).

But no one yet knows for sure what exactly is going on underneath Klyuchevskoy and its associated volcanoes Kamen, Bezymianny, and Tolbachik.

Of note, Kayzar et al. do describe Klyuchevskoy’s lava chemistry as “primitive” — that is, very much like the mantle material that we know is erupting at underwater spreading ridges that manufacture seafloor basalt in all of the world’s oceans.

Not shown: A mid-ocean spreading center. Klyuchevskoy is the active volcano on the left. For local residents, light to moderate ashfall is the main predictable volcanic hazard, but Klyuchevskoy’s lava flows have gotten to within three miles of this town (Kliuchi) in the recent past.

Why would something akin to seafloor basalt be rising up from the mantle and erupting from Kluchevskoy, which sits on the Kamchatka Peninsula’s continental crust?

It’s complicated.

I give a major hypothesis, attempting to explain the situation down there, in a Holmesian way at the end of this post.

But first, here is some basic information about this active Kamchatkan giant.


56.056° N, 160.642° E, in Kamchatka Region, Russian Federation. Klyuchevskoy’s GVP Volcano Number is 300260.

Nearby Population:

Per the Global Volcanism Program:

  • Within 5 km (3 miles): 0
  • Within 10 km (6 miles): 0
  • Within 30 km (19 miles): 292
  • Within 100 km (62 miles): 12,406
  • And overhead, local air traffic as well as the major international air routes between Asia and North America.

Current Status:

Aviation Code Green in late 2021, per the GVP; I can’t find any more recent updates.


  • Eruption styles: The Global Volcanism Program puts it this way (emphasis added):

    Klyuchevskoy, with Kamen on the right. (Image: Игорь Шпиленок via Wikimedia)

    Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-[15,597-foot]-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive [lava flow] eruptions without major periods of inactivity.

    Ashfall, lava flows, and/or lahars (mudflows) from Klyuchevskoy’s eruptions occur at the summit and, especially since 1932, from flank vents.

    Will Klyuchevskoy one day collapse, as Kamen did? Yes, probably — it’s a fairly common event at active Kamchatkan volcanoes, per Ponomareva et al., 2006.

    They speculate, that if and when Klyuchevskoy has a sector collapse, as Kamen did thousands of years ago, the debris likely will head southeast, not north toward Kliuchi.

  • Biggest recorded eruption: The GVP lists three VEI 4 eruptions for Klyuchevskoy: 1829; 1931; and 1986- 1990, when the summit and several flank vents were active.
  • Most recent eruption: 2021.
  • Past history: This is a very active volcano. See the GVP for details.


    Kamchatka Volcanic Eruption Response Team (KVERT).

    Tokyo Volcanic Ash Advisory Center (VAAC).

    Now then, in 2020 I tried to carry on the “murder mystery” analogy to describe what I understand of the main hypothesis about the forces behind this group of volcanoes, using a familiar popular detective.

    It’s rather incoherent, but I’ll leave it as is (except for some minor editing) and hope that it still makes some sense to everyone.

    For more information, please do check the references (jargon alert).

    The Klyuchevskoy Volcano Group

    Holmes and Watson never made it to Kamchatka, but volcanologists there must use the same inductive reasoning that Holmes did to explain the mysterious underground processes that produced gigantic Klyuchevskoy and now keep it alight.

    It’s cutting-edge research, too. After all, this is one of the world’s largest volcanic centers, accounting for more than half of all the output from volcanoes in Kamchatka AND the Kuril Islands to the south. (Sorenko et al.)

    This is actually in Chile, but the fieldwork is always the same. The people are tiny in size, but their spirit towers over the volcano. (Image: Tuffen, CC BY-NC 2.0)

    But what layperson wants to know the dry geophysical, morphological, and geochemical details?

    Like Conan Doyle’s readers, we’d all rather be thrilled and puzzled as a story unfolds. And at the end, of course, there must be a surprising but satisfying solution.

    Well, when it comes to the Klyuchevskoy group, there certainly are thrills and wonders to share, although mysteries here still outnumber solutions.

    So I’m going to do a Holmes & Watson here and hope for the best.

    Let’s set the stage:

    “Kliuchevskoi”? Sure. There are several ways to spell Ключевской in English. (Image: NASA/Edited and labeled by Ponomareva et al. 2007 as Figure 4)

    The questions ask themselves:

    1. Why are those huge volcanoes in the top picture clustered together?
    2. What’s a Plosky?
    3. Why are they all sitting in a valley? (Wait. Kamchatka has mountain ranges as well as volcanoes?)

    Some of the best minds on this planet are busy trying to work out detailed answers to those questions.

    Here is how Sherlock Holmes might describe to Dr. Watson what I have learned from reading a few of their published results (apologies to Sir Arthur Conan Doyle):

    1. What’s the volcano cluster in the top image?

      Those are the fire mountains we have already met, as seen from the south.

      Spread across a horizontal distance of about six miles are smouldering Bezymianny in the foreground, then “dead” Kamen, and to the north, Klyuchevskoy.

      On the second image, you can see Tolbachik holding its crazy luaus a few miles to the southwest of the Terrible Trio. Its runny red lavas form the plain south of Tolbachik’s vents.

      As well, there are other volcanoes in the Klyuchevskoy group, south of that dotted line that marks the Kamchatka River — many more than this satellite image can show — but those aren’t active.

    2. “Plosky”?

      That’s Russian for “flat,” and it’s used in several names.

      The full moniker for that flattish massif behind our Trio is Plosky Sopkie (or Sopka, depending on the writer).

      It’s actually a two-for-one deal: flat-topped Ushkovsky and the stratovolcano Krestovsky, described by Koulakov et al. as dormant.

      Ushkovsky’s last eruption was in 1890, but it still has fire in its belly, as shown by seismicity and active fumaroles on one of its cinder cones.

      Here’s another interesting point.

      You can’t really see it in those images, but Plosky Sopkie contains more igneous rock than all the rest of the group put together, including the two giants.

      Huge volumes of lava have come out of the ground here.

      And then we have to factor in what’s underground.

      Plosky Sopkie sits right over the center of an underground basalt lava plateau that dwarfs anything we see now in Central Kamchatka.

      This Pleistocene volcanic field, buried by today’s edifices, was active from around 260,000 to 60,000-70,000 years ago. (Churikova, 2013, Figure 3)

      Add it all up, and that’s a lot of lava.

      Watson: Where did it all come from?

      Holmes: All in good time, Watson. Next question.

    3. Why does the Klyuchevskoy group of volcanoes sit in a valley?

      Because it’s a rift valley.

      Those mountain ranges on either side are actually volcanic belts. Kamchatka has two or three of these, depending on your source.

      Following Ponomareva et al, 2007, they are:

      • The Eastern Volcanic Belt (which, by the way, includes Decade Volcano Avachinsky-Koryaksky).
      • The CKD (Central Kamchatka Depression) Volcanoes, including Klyuchevskoy’s group south of the river and a slightly different set of “stone torches,” like Shiveluch, to the north.
      • The Sredinny Range to the west. Experts disagree on whether this belt can still produce eruptions, since it apparently has been very quiet during recorded history.

      There is a deep trench just off Kamchatka’s coast (call it Moriarty, if you wish), and plate tectonics is at work here.

      Though it’s operating in a very different situation compared to, say, the famous East African rift valley, the overall effect is the same — a plume of molten rock rises and the overlying land stretches out and drops.

      Watson: I don’t follow you, Holmes.

      Holmes: It’s quite simple, really.

      As you may have heard, the continent of Africa is splitting apart.

      Someday, the pride lands and our own ancestral home will be a mid-ocean spreading center.

      Kamchatka, on the other hand, is in a collision zone where the northwest Pacific plate and the continental plate meet.

      The Pacific seafloor is heavier than the continent, so it takes a dive under the land’s leading edge, rumbling slowly down into the mantle, where it melts.

      Underground, this process results in lots of molten rock as well as water and dissolved gases squeezed out of the seafloor slab.

      At the crustal surface, barring any complications, we see:

      • A deep ocean trench
      • A line of volcanoes several miles in from the trench — either on land or as an island arc, depending on circumstances
      • Farther inland, behind the volcanoes, what is called back-arc rifting of the crust.

    Now, if this were a drawing room and the fictional detective was summing up, Dr. Watson might break in to say, “That’s all well and good, Holmes, but it’s true of all such places. Yet you’ve just gone into a lot of detail about how unusual these Russian volcanoes are! And what about that 20-mile-long pipe we heard about?”

    Unfazed, Sherlock Holmes might respond this way.

    “The processes I have just described happen at Kamchatka, as they do at all subduction zones. Therefore something else must be causing these unusual features you mention, Watson.”

    Watson: “What could it be?”

    Holmes: “Let us look at the map.

    Williamborg via Wikimedia, CC BY-SA 3.0

    “There is our Kamchatka Peninsula in the lower left, complete with Moriarty, the subduction trench, offshore.

    “That green area in the center of Kamchatka is our central rift valley, and I believe that brown area under the “nin” in “Peninsula” to be the CKD volcanoes.

    “Now look here, Watson. This curving line across the map is Alaska’s Aleutian Islands.”

    Watson: “Why, they have a subduction trench, too!”

    Holmes: “Very observant. That dark blue line, in either case, is clearly a trench. Therefore, the Pacific plate must be subducting in two directions here.”

    “Good Lord, Holmes! Can it do that?”

    “Well, it is doing that, Watson, though the geometry must be complex, especially with that line of seamounts coming in at an angle.”

    Watson: “Well, that tears it. I don’t know what to make of things anymore.”

    “A tear! Watson, you’re a genius! If there is a tear in the Pacific plate at that Kamchatka-Aleutian corner, whatever the cause, then all is explained.”

    “Is it?”

    Holmes: “Of course. Theoretically, such a tear could allow underlying mantle material to flow around the edge of the subducting Pacific plate, which is below the Central Kamchatka rift valley and its volcanoes.

    “This extremely hot material will produce more melt than is ordinarily seen at subduction zones. Hence the great pile of lava, past and present, at Klyuchevskoy and other volcanoes in the valley.”

    “And the 20-mile-long pipe, Holmes?”

    Holmes: “Ah, more work must be done to completely understand that. But according to my friends Koulakov et al., we should be grateful that it exists.”

    Watson: “Why?”

    Holmes: “They also have studied the Toba supervolcano down in Indonesia and find similarities between it and the geological situation in Kamchatka.

    “In both cases, there are large quantities of magma, underneath the volcano at the boundary between Earth’s crust and its mantle.

    “At Toba, this molten material has repeatedly reached the surface the only way it could: through some of the largest volcanic eruptions ever to occur on this planet.”

    “But that hasn’t happened at Kamchatka, Holmes.”

    Holmes: “No, indeed. Nor are there any signs of any impending catastrophe.

    “Koulakov’s team suggests that this is because the volcano Klyuchevskoy taps into that great body of molten rock — cubic miles of the stuff, Watson! — rather like a relief valve.”

    Watson: “I see. That’s reassuring.”

    Holmes (closing with typical Victorian hyperbole): “Well, Watson, I don’t know how many volcanologists subscribe to this view. It is a highly cited report by well-known experts, however.

    “And if this hypothesis is ever verified, then humanity can recognize and honor the volcano Klyuchevskoy as not only a spiritual center of primary importance to the local First People, but also as a global guardian of our modern way of life.”

    Special thanks to the author who introduced me, at a young and impressionable age, to the importance of objective observation and critical thinking while taking me on so many pleasant adventures, from a boat trip up the Amazon to rail journeys across Victorian England in search of clews.


    March 2021 2022: Referencing the sad topic of my rant in the Bezymianny repost, what good does Victorian hyperbole do for the Russian people today, caught behind their Russian-imposed ‘iron curtain’?

    I’m just going to leave this clip from Alexander Nevsky here and wish them well in overcoming this unprecedented situation, what could well be called the attempted Russian conquest of Rus by comparatively few people for merely geopolitical and personal glory.

    It will fail, as all such attempts have, but at what cost, I wonder.

    Featured image: Vita Fortuna/Shutterstock


    Some of these sites are in Russian and were translated by the browser.

    Active Volcanoes of Kamchatka. n.d. Klyuchevskoy. Last accessed October 1, 2020.

    Belousov, A.; Voight, B.; Belousova, M.; and Petukhin, A. 2002. Pyroclastic surges and flows from the 8–10 May 1997 explosive eruption of Bezymianny volcano, Kamchatka, Russia. Bulletin of Volcanology, 64(7): 455-471.

    Bogoyavlenskaya, G. E.; Braitseva, O. A.; Melekestsev, I. V.; Kiriyanov, V. Y.; and Miller, C. D. 1985. Catastrophic eruptions of the directed-blast type at Mount St. Helens, Bezymianny and Shiveluch volcanoes. Journal of Geodynamics, 3(3-4): 189-218.

    Brown, S.K.; Jenkins, S.F.; Sparks, R.S.J.; Odbert, H.; and Auker, M. R. 2017. Volcanic fatalities database: analysis of volcanic threat with distance and victim classification. Journal of Applied Volcanology, 6: 15.

    Churikova, T. G.; Gordeichik, B. N.; and Ivanov, B. V. 2012. Petrochemistry of Kamen volcano: A comparison with neighboring volcanoes of the Klyuchevskoy group. Journal of Volcanology and Seismology, 6(3): 150-171.

    Churikova, T. G.; Gordeychik, B. N.; Ivanov, B. V.; and Wörner, G. 2013. Relationship between Kamen Volcano and the Klyuchevskaya group of volcanoes (Kamchatka). Journal of Volcanology and Geothermal Research, 263: 3-21.

    Global Volcanism Program. 2020. Kamen
    Last accessed September 15, 2020.

    Kamchatka Volcanic Eruption Response Team (KVERT). 2020. Klyuchevskoy. Last accessed October 1, 2020.

    Kayzar, T. M.; Nelson, B. K.; Bachmann, O.; Bauer, A. M.; and Izbekov, P. E. 2014. Deciphering petrogenic processes using Pb isotope ratios from time-series samples at Bezymianny and Klyuchevskoy volcanoes, Central Kamchatka. Contributions to Mineralogy and Petrology, 168(4): 1067.

    Khubunaya, S. A.; Gontovaya, L. I.; Sobolev, A. V.; and Nizkous, I. V. 2007. Magma chambers beneath the Klyuchevskoy volcanic group (Kamchatka). Journal of Volcanology and Seismology, 1(2): 98.

    Koulakov, I.; Abkadyrov, I.; Al Arifi, N.; Deev, E.; and others. 2017. Three different types of plumbing system beneath the neighboring active volcanoes of Tolbachik, Bezymianny, and Klyuchevskoy in Kamchatka. Journal of Geophysical Research: Solid Earth, 122(5): 3852-3874.

    Oregon State University: Volcano World. 2020. Bezymianny. Last accessed September 15, 2020.

    Photovolcanica. n.d. Kliuchevskoi. Last accessed October 1, 2020.

    Ponomareva, V. V.; Melekestsev, I. V.; and Dirksen, O. V. 2006. Sector collapses and large landslides on Late Pleistocene–Holocene volcanoes in Kamchatka, Russia. Journal of Volcanology and Geothermal Research, 158(1-2): 117-138.

    Ponomareva, V. V.; Churikova, T.; Melekestsev, I. V.; Braitseva, O. A.; and others. 2007. Late Pleistocene-Holocene volcanism on the Kamchatka Peninsula, northwest Pacific region.

    Shapiro, N. M.; Sens-Schonfelder, C.; Luhr, B. G.; Weber, M.; and others. 2017. Understanding Kamchatka’s extraordinary volcano cluster. Last accessed September 15, 2020.

    Shevchenko, A. V.; Dvigalo, V. N.; Walter, T. R.; Mania, R.; and others. 2020. The rebirth and evolution of Bezymianny volcano, Kamchatka after the 1956 sector collapse. Communications Earth & Environment, 1(1): 1-15.

    Sorenko, V. A.; Droznina, V.; Ivanova, P. I.; and others. 2004. Bezymianny, in Active Volcanoes of Kamchatka. Last accessed September 15, 2020.

    Thelen, W.; West, M.; and Senyukov, S. 2010. Seismic characterization of the fall 2007 eruptive sequence at Bezymianny Volcano, Russia. Journal of Volcanology and Geothermal Research, 194(4): 201-213.

    Volcano Discovery. 2020. Klyuchevskoy. Last accessed October 1, 2020.

    Wikipedia. 2020. Klyuchevskaya Sopka. Last accessed October 1, 2020.

    ___. 2020. Tolbachik. Last accessed October 13, 2020.

    Wikipedia (Russian). 2020. Klyuchevskaya Sopka.Ключевская_Сопка Last accessed October 1, 2020.

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