“It seems that the earth is alive. Constantly the ground is vibrating, one hears the booming and rattling sound when blocks separate from the walls of the volcano, falling off, disintegrating into large masses of rock debris and rolling down into the valley. One feels as if in the center of the earth, no doubt: from under your feet the fiery lava will break within the next minutes… The most majestic picture opens for the traveler arriving on top of Mutnovsky’s Active crater – he’s stunned by the great hissing fumaroles, surrounded by bright yellow sulfur crystals, hot bubbling mud pots and boiling lakes inside the deep abyss. All of this exotic interior bubbles, hisses, spits hot spray and produces clouds of steam and hydrogen sulfide, surrounded by cliffs with hanging curtains of blue glacier ice.”
A good few descriptions similar to the above can be found on the internet, and looking at the photos can make a volcanoholic’s and passionate hiker’s mouth water… if it wasn’t so remote and the flights not so expensive, Kamchatka would be my next year’s holiday destination! So let’s content with a virtual tour…
(For the question What drives volcanism on Kamchatka, and the tectonics behind it all, please see agimarc’s great article “Tectonics of the Kamchatka Peninsula“.)
Mutnovsky volcano (Russian: Мутновская сопка or вулкан Мутновский) is part of the southern volcanic belt of Kamchatka, about 70 km to the SW from Petropavlovsk-Kamchatsky, within the Natural Park of “Yuzhno-Kamchatsky”. The complex is an older structure, probably from the Middle Pleistocene. It consists of four overlapping stratovolcanoes capped by a number of summit craters. It is thought that this volcano is possibly located in an old ruined caldera with a diameter of about 9 km. Originally there might have been one stratovolcano, later a second emerged on the northwestern slope of the first. Over time the caldera of the first volcano got filled with ejecta from the second cone. Vostochny, the eastern cone, is now the highest point with 2,323 m a.s.l..
The volcano has developed in four main stages, each reflecting the evolution of a small magma reservoir and a shift of the eruptive centre by as much as 1km. The shape we see now represent stages III and IV. Mutnovsky III ended its career with a Holocene eruption of dacitic pyroclastic flows and emplacement of a dacite dome within its crater. The first three stages have produced magmas ranging from basalt to dacite, while the latest stage erupted basaltic andesites.
The youngest part of the volcano, dubbed Mutnovsky IV, was established in the early Holocene. Its 8-shaped double crater (N and S crater) is 1.5 x 2.1 km wide, with steep walls ca 50-250 m high. Inside it has an intracrater cone, several flank cinder cones, two lakes and it is partially glaciated. Four smaller craters – including the presently active Aktinaya Voronka – cut the northern rims of the double summit crater complex.
There have been 18 reported eruptions since historical records began in the 17th century; most of these have been explosive, and lava flows occurred only during the 1904 eruption (however, in 2010 there is a debate about the accuracy of lava flow reports in 1904). Explosive eruptions producing ash occurred in 1848-54, 1898 (Strombolian eruption), 1945-52, 1960, 2000, 2007, 2013 and possibly a few small ones in the following years.
Active crater has been enlarged by explosion, collapse, and/or erosion and is now occupied by a crater glacier. The crater of Mutnovsky III is the scene of intense fumarolic activity, modestly superheated and arranged in a ring, apparently defining the conduit margin of the late dacite lava dome. A powerful phreatic explosion in 2000 at the edge of the adjoined Mutnovsky IV crater reopened a large pre-existing subcrater. This event appears to have been caused by a dike propagating upward and intersecting the hydrothermal system centered beneath Mutnovsky IV. A second powerful explosion occurred in 2007, excavating a new sub-crater on the floor of Active crater.
A “NATURAL CHEMICAL REACTOR”
There are numerous fumaroles inside the northern crater and on the outer slopes; two geothermal fields, Verkhenye and Donnoye, feed their waters into the Vulcannaya river valley down the NW slope. Fumaroles are as hot as 620°C; sulfur cupolas with heights up to 2.5 m and diameters up to 5 m are deposited around some of the vents – the area is known as Little Valley of Geysers (Russian: Малая долина гейзеров, referring to the more famous Valley of Geysers, further to the north). The high temperatures and SO²-rich gas emissions imply shallow magma storage locations beneath the volcano, in fact, local earthquake activity indicates that a large magma emplacement zone (magma chamber) has developed at 5-7 km depth below the Mutnovsky geothermal field.
An isotopic geochemistry study has been performed on the trace metals in the fumaroles. The solutions in the boilers have compositions that appear to be unique in the world due to extremely high contents of Cl, Cr, Ni, Co, Ti, V, and B. These elements are extracted from magma and wall rocks by acid magmatic gases and then concentrated in zones of secondary boiling. Thus, a modern ore-forming zone exists in the region of brine formation. To gechemists, fumaroles depositing pyrites and arsenopyrites explain the remarkable chemistry (for example, the highest fumarolic Cr concentrations ever recorded).
Mutnovsky’s fumaroles are an epithermal ore-depositing system in action and have been termed “a unique natural chemical reactor”, where thirty-five previously unknown hydrothermal minerals have been discovered, some of them as yet unnamed. One has been named Tazieffite (Pb20 Cd2 [As,Bi]22 S50 Cl10), in reverence to the well-known French volcanologist and geologist Haroun Tazieff. For this mineral, as well as for Mutnovskite (Pb2 As S3 [I,Cl,Br]) Mutnovsky volcano is the Type Locality.
A single fault represents the geothermal production zone at Mutnovsky, which appears to connect directly with the active magma column, feeding the > 700°C fumaroles. An aspiring – and exciting – project has been proposed around 2009 by Kamchatkan and Alaskan scientists to directionally drill into the fracture zone at a point between the active vent and the production field, in order to test the relationship between the two systems. “Mutnovsky Scientific Drilling Project would help to answer two important questions: (1) By drilling closer to active andesitic volcanic centers of subduction zone arcs, can we expect to encounter higher energy hydrothermal systems? (2) By increasing the rate of energy extraction from magma-driven hydrothermal systems to a rate comparable to the magmatic thermal input, can we expect to extend repose time and diminish the likelihood of hazardous eruption?” – Alas, I have been searching up and down the internet but could not find anything relating to this project in recent years, perhaps the project was turned down?
Since Mutnovsky has the highest heat capacity of any volcano in the Kuril-Kamchatka arc a geothermal power plant was a logical conclusion. It has been constructed at the foot of the volcano, 1000 meters above sea level, and consists of two power blocks, providing an output of 47 megawatts. Overall the Mutnovsky power plant applies hot water from 17 wells. The “used” cold water is pumped back through six holes into the ground, so it can be re-heated. The power plant represents an important pillar of Kamchatka’s energy supply – the prices for remote energy are 50 to 100% higher than the Russian average due to high transportation costs. Therefore, keeping the plant modernized and big time increasing the production figures are scheduled for the site in the coming years.
On the Global Volcanism Program Weekly Reports were posted in 2005 (1) and 2008 (3), mostly stating that activity has decreased and the alert level has now been lowered to green. What had happened before? GVP bulletins are available only from 1993 to 2000…. there really seems to be nowhere to look for up to date information on Mutnovsky.
08/1993 A large rock slide (hundreds of thousands of tons of material) buried ~300 m of a trail in the crater under big blocks up to several meters high. Explosions from a vent in the central part of the crater ejected boiling mud several meters high. IVGG is advising hikers and other visitors to stay out of the crater until further notice.
12/1996 A fumarolic plume was observed rising to a height of 1 km above the crater.
03/2000 Two minor phreatic explosions occurred at Mutnovsky. Subsequent helicopter observations indicated that the eruption took place in the N crater of the volcano. This crater had been active prior to the middle 1950’s, but was snow-and-ice filled over the last 20 years. The recent eruption produced small amounts of ash and blocks of altered rocks. followed by low-frequency volcanic tremor.
Clearly expressed precursors had provided strong indications that an eruption could be expected. In effect, scientists noted that over the last 20 years the heat output from the main crater increased and was accompanied by the appearance of new fumarolic grounds and an increase in the fumarolic temperature. They also detected that a sudden activation of the alpine glacier had started about 5 years ago. Scientists also observed that during the last 5 years, the relative abundance of the chemical elements S/Cl and S/F in the water of Vulcannaya River, which drains the fumarolic fields of the NE and SE craters, increased 3- to 5-fold. The low magnitude of the 16 March event, the seismicity which continued afterwards for several months, and the relatively long period of preparation may indicate that the explosion is merely a precursor to a stronger eruption in the near future.
09/2000 Fumarolic activity continued from June through mid-October 2000. Volcanic tremor was slightly above background levels until it increased markedly on 26 June. The next day, seismicity indicated another short-lived vigorous phreatic(?) eruption.
… and here ends all reporting on GVP, as well as their Eruptive History. Nothing on the 2007 ash eruption, nothing on the same of 2013… WHY?
The following infos I found in papers, overviews and reports for conferences, some paywalled (meaning I’ve had access to the abstract only), and apparently none of them was thought for general public use:
2007: KVERT reported an increase in seismicity in the vicinity of Gorely and Mutnovsky Volcanoes but were unable to verify the exact volcanic source. First, a yellow alert level was raised for Gorely, but, Mutnovsky being only 13,5 km southeast of Gorely and both volcanoes monitored by a single seismometer, KVERT expanded the raised concern alert to include Mutnovsky Volcano on December 27, 2007. Later KVERT learned of a phreatic explosion that had occurred at Mutnovsky on April 16 or 17, 2007. The event was confirmed by field evidence of ejecta and analysis of fresh ash fall; evidence for this event also was noted in hindsight on satellite imagery (Girina and others, 2008a).
2013: “Several moderate phreatic explosions were noted by observers at Active crater of Mutnovsky volcano on July 03. Ash plumes were not noted on satellite images.
Some studies link the renewed hydrothermal explosion activity (and also the fluctuation of deformation measurement results) to the increasing exploitation of the hydrothermal resources under Mutnovsky. There have been 40 earthquakes recorded from February 2009 to December 2013, ranging from M 4.0 to 7.1, at 2 to 6 km depth, and the crater lakes at both the Mutnovsky and Gorely volcanoes were drained in 2004 and 2012, respectively. – On the other hand, this is a seismically very active region where times with increasing numbers of EQs and eruptions could also occur any time naturally, without human input.
MUTNOVSKY (and Gorely) AS A TOURIST ATTRACTION – is it safe to go?
Mutnovsky and its neighbor Gorely today are a tourist attraction; day tours on jeeps take you to the foot of the volcanoes, and well-trained local guides lead you up to the craters. That must be very exciting but, honestly… I wouldn’t – at least not before inquiring about the present situation of monitoring – and getting a convincing reply!
Reading scientific reports and travel logs lets me think of several risks on Mutnovsky… The constant feeling like movement of the ground mentioned by hikers is caused by deep rumbling of subglacial torrents, by the vibration of rocks rolling down slopes and by steam working its way up through the debris. Well, as everybody knows, it’s not just steam coming up the hydrothermal system. In the bottom of a crater there is a good chance of toxic gases to accumulate in lethal concentrations, and this might, imho, be the biggest threat here to visitors. The rock slides are a result of microearthquakes working on the poorly consolidated debris, aided by the difference between night and day temperatures. The tiny earthquakes are not felt by people, but a slope failure of the crater walls might come unexpectedly and could end deadly.
Various papers state that in 2005 “there is no seismic station on Mutnovsky”, and in 2009 “there are no seismic stations in the area around the volcano. The nearest one is near Gorely Volcano at a distance of about 12 km to the northwest. In this situation, it is impossible to define seismic activity at Mutnovsky Volcano on a satisfactory level”. – I have tried to find out about current seismic stations but EMSD and KVERT public pages are not updated in that regard. The latest I find is that in 2014 there are three stations (telemetric only) in the broader area: GRL (at V. Gorely, 12km NW), RUS (Russky Bay, 10km E) and MTV (Mutnovka, 4km N). So, for that constellation, everything going well your life may depend on one (1) station – if it IS working – when visiting one of the most active volcanoes in Kamchatka.
Having said this, of course I really don’t know the situation right now. There *might* be a better network for monitoring Mutnovsky now, and the tour guides *might* have a connection to the scientists working with it. But I for one would like to play safe and get informed BEFORE I travel… and I would NOT take the risk climbing into these volcanoes when they – perhaps – are not being monitored at all.
Disclaimer: I am not a scientist, all information in this (and any of my other posts) is gleaned from the www and/or from books I have read, so hopefully from people who do get things right! If you find something not quite right, or if you can add some more facts, please leave a comment.
Enjoy! – GRANYIA
SOURCES & FURTHER READING
– GVP, Mutnovsky
– The Magma-Hydrothermal System at Mutnovsky Volcano (2009, PDF)
– Mutnovsky Volcano (1991, PDF)
– A guide to the volcanoes of southern Kamchatka, […] (2001, PDF)
– Necessity of Local Seismic Monitoring in the area of Mutnovsky GeoPPs (2005)
– Webmineral.com, Mutnovskite
– Explosive Eruptions of Kamchatkan Volcanoes in 2013 and Danger to Aviation (2014)
– 2007 Volcanic Activity in Alaska, Kamchatka, and the Kurile Islands: […] (2010)
– Modeling of the Vertical Deformations […] Mutnovsky Geothermal Field (2015, PDF)