Kliuchevskoi (also called Klyuchevskaya and Klyuchevskoy) has been quite active for many decades. During January 2009-February 2010, the volcano experienced Strombolian activity, lava flows, vigorous plume emissions, and a growing cinder cone (BGVN 35:06). This report discusses activity from 19 February 2010 through 15 November 2013, based on reports from the Kamchatkan Volcanic Eruption Response Team (KVERT). A map of the Kamchatka Peninsula is provided in figure 13. A summary of plumes between 12 Feb 2010 and 14 November 2013 is provided in Table 14 which, because of its length, is near the end of this report.

Figure 13. Map of Kamchatka Peninsula showing location of Kliuchevskoi. Courtesy of Lost World, Ltd. (Travel Kamchatka).

Active period: 19 February to 4 November 2010. Seismic activity during this period was consistently above background levels, and the explosive-effusive eruption of the volcano continued. Almost every week, KVERT reported periodic Strombolian activity that ejected material 100-300 m above the crater. Ash plumes and gas-and-steam emissions were common events, with some plumes rising to altitudes as high as 10 km (table 14). Nearby communities such as Klyuchi (30 km NNE) experienced ashfall. Satellite images consistently revealed a large daily thermal anomaly at the volcano.

Lava flows descended the NW, S, and NE flanks until about 1 May 2010 when such flows apparently ceased for more than two months. However, ground observations were sometimes prevented due to meteorological cloud cover. A satellite image from 9 March 2010 showed that the S-flank flow was about 1.3 km long.

A news article (Itar-Tass) reported a new lava flow from a fissure on 8-9 July. According to KVERT, during 16-23 July 2010, an effusive lava flow began to descend the SW flank. In subsequent weeks, lava flowed down the SSE flank (23 July-5 August), SW flank (6 August-29 October), NW flank (3-10 September), and W flank (8-29 October). These flows continued until about 29 October 2010. Phreatic explosions sometimes occurred from the fronts of the lava flows. KVERT specifically reported such explosions weekly during 19 February-12 March 2010, and on 29-30 August 2010 and 5 September 2010.

According to KVERT, ash plumes were common (table 14) and ashfall in nearby communities were sometimes reported.

Between 19 February 2010 until about the last week of October 2010, heightened seismic activity was relatively consistent. On 23 October KVERT reported increased seismicity, characterized by an abrupt increase in volcanic tremor and explosive activity. The Aviation Color Code, which had been at Orange throughout the reporting period, was raised to Red on 23 October 2010 (table 15 defines KVERT's Aviation Color Codes). On 30 October explosive activity decreased along with the magnitude of volcanic tremor. The Aviation Color Code was lowered to Orange. (Table 15 indicates KVERT's Aviation Color Code levels.)

During 30 October through 3 November 2010, seismic activity was still above background levels. Strombolian activity was observed, and KVERT even reported Vulcanian activity that produced ash plumes rising to an altitude of 7 km. A news article (Associated Press) from 29 October stated that ash from Kliuchevskoi and Shiveluch caused area flight diversions. On 4 November, seismicity sharply decreased and only gas-and-steam activity was observed. The Aviation Color Code was lowered to Yellow. According to KVERT, the eruption that had begun in August 2009 had finally terminated by 4 November 2010, and that seismicity had continued to decrease.

Less active period: 5 November 2010 to 31 October 2013. KVERT reported that during 8 November to 17 December 2010, seismic activity at Kliuchevskoi was at background levels or slightly above. A weak thermal anomaly over the crater was observed in satellite images.

During 9-10 and 16-18 November 2010, KVERT observed strong fumarolic activity, and ash plumes and gas-and-steam plumes occurred periodically. Cloud cover frequently prevented observations. About 24 November 2010, the Aviation Color Code was raised to Orange, presumably due to daily strong fumarolic activity and an ash plume that rose 5 km on 24 November. Ash fell in Kozyrevsk (about 50 km W) on 27 November and in Klyuchi (30 km NNE) on 28 November 2010. Strombolian activity was observed during 1-2 December 2010.

According to KVERT, activity declined during 10-17 December 2010, and the Aviation Color Code was lowered to Yellow. Gas-and steam emissions were observed during 10-13 December. Clouds frequently obscured the volcano during December.

During 4-11 February 2011, KVERT reported that seismic activity, although moderate, had essentially decreased, and lowered the Aviation Color Code to Green around 10 February. Satellite images showed a weak thermal anomaly over the crater on 6 and 7 February.

During 2011, KVERT observed only periodic ash plumes (table 14). An ash plume on 29 May 2011 that rose to an altitude of 5 km prompted KVERT to raise the Aviation Color Code to Orange. However, the lack of further activity the next day prompted KVERT to return it to Yellow, and then Green. Moderate gas-and-steam emissions were observed on 30 May and 1 June; cloud cover prevented observations on the other days of the week.

Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that an eruption on 3 July produced a plume that rose to an altitude of 7 km.

The KVERT website has no reports on Kliuchevskoi between 10 February 2011 and the end of September 2012, other than the Aviation Color Code was Green. In October 2012, KVERT reported that seismic activity at Kliuchevskoi had been gradually increasing since June 2012. Episodes of volcanic tremor first detected on 21 June continued through 14 October. A weak thermal anomaly was detected in satellite images during 1 September-14 October, 23-26 November, and 7-8, 10, 12-13, 16 and 18 December (and possibly additional dates). Strombolian activity was observed at night during 13-15 October, 23-30 November, and 30 November-21 December. Clouds frequently hampered detection on other dates. During periods of Strombolian activity, crater incandescence and gas-and-steam emissions were also detected. KVERT raised the Aviation Color Code to Yellow in mid-October. According to KVERT, activity at Kliuchevskoi decreased in late 2012 (around the same time the Tolbachik eruption began).

KVERT weekly reports noted that during January to the middle of March 2013, weak-to-moderate seismic activity, Strombolian explosions, and weak-to-moderate gas-and-steam emissions continued. (Gas-and-steam activity was moderate-to-strong in late February.) During January, incandescence at the summit was occasionally observed and satellite data sometimes showed a weak thermal anomaly at the summit. Clouds obscured the volcano frequently. On 18 March the Aviation Color Code was lowered to Green.

KVERT issued no reports on Kliuchevshoi between 21 March 2013 and the middle of August 2013. Presumably, the aforementioned activity, with some Strombolian explosions, continued at a low level.

On 15 August, a new explosive eruption began, with renewed Strombolian activity. Video data showed incandescence at the summit at night, and gas-and-steam plumes containing a small amount of ash rose up to 5.5 km. Satellite data showed a large, bright thermal anomaly over the volcano during 15-17 August.

The moderate seismic activity and Strombolian eruption continued through early October 2013. Incandescence at the summit was observed at night, and gas-and-steam plumes containing a small amount of ash rose up to an altitude of 5.5 km. Satellite data showed a thermal anomaly over the lava dome during this time, except where clouds obscured the volcano. On 26 August, a new lava flow on the WSW flank was observed. By 26 September, four lava flows were observed on the NW, W, SW flanks (figure 14). On 1 October, satellite data showed an ash plume extending about 100 km to the ESE.

Figure 14. Photo of Kliuchevskoi on 27 September 2013 showing Strombolian activity and several lava flows on the NW flank. Courtesy of Yu. Demyanchuk, KVERT.

In early October 2013, seismic activity gradually increased, and on 6 October a sharp increase of tremor occurred. According to video data, a flank eruption around this time began at the pass between Kliuchevskoi and Kamen volcanoes (Kamen's summit is only 5 km SW of Kliuchevskoi's). Local incandescence and gas-and-steam plumes were observed from the pass, and video data showed incandescence at Kliuchevskoi's summit and the W flank at night, and gas-and-steam plumes containing ash. Strombolian activity continued and several lava flows traveled down the NW, W, SW flanks. Occasionally, phreatic-generated plumes were observed at the fronts of lava flows. Ash plumes rose to an altitude of 6 km during 9-10 October and minor ashfall was noted at Klyuchi Village. A large thermal anomaly was recorded.

By the middle of October, the increasing activity prompted KVERT to upgrade the Aviation Color Code to Red, the highest level. During 15-16 October, video data showed strong Vulcanian explosive activity, and an ash plume rose to an altitude of 10 km. Strong incandescence was observed at the summit and W flank at night. Strombolian activity, several lava flows, and phreatic plumes continued, with ash rising to 5 km and causing minor ashfall in nearby communities. Numerous lava flows on the SW flank and a probable flank eruption at the pass between Kliuchevskoi and Kamen volcanoes led to vigorous melting of Bogdanovich glacier; the resulting water increased the Studenaya River's flow, which then destroyed part of the road near Kozyrevsk village (about 50 km W).

During 18-20 October, the eruption peaked and was characterized by high seismic activity, strong Vulcanian explosions, lava flows, intense incandescence, and ash plumes that rose to an altitude of 12 km and extended in various directions. Strombolian activity continued with lava fragments ejected 500-800 m above the summit cinder cone. A photo of the volcano on 20 October 2013 is shown in figure 15.

Figure 15. NASA Earth Observatory photo of Kliuchevskoi taken on 20 October 2013 by the Operational Land Imager on Landsat 8. According to the caption (written by Adam Voiland and Robert Simmon), multiple lava flows streamed down Kliuchevskoi's N and W flanks. The top, false-color image shows heat from the flows in a combination of shortwave-infrared, near-infrared, and the green band. Ash, weather clouds, and steam appear gray, while snow and ice are bright blue-green. Bare rock and fresh volcanic deposits are nearly black. In the wider natural-color (red, green, blue) image, snow and clouds are white, the ash plume is light gray, and forests (with trees tall enough to stand above the snow cover) are dark brown. Courtesy of NASA Earth Observatory (images by Robert Simmon).

The eruption intensity decreased on 20 October, and on 30 October, KVERT lowered the Aviation Color Code to Yellow. However, moderate seismic activity and strong Strombolian activity persisted into at least late November 2013, along with several lava flows on the SW, SE flanks. In addition, KVERT video data showed strong fumarolic emissions and occasional ash plumes. Large thermal anomalies continued to be recorded.

On 18 November 2013, KVERT raised the Aviation Color Code to Orange, probably due to weak Vulcanian activity.

An airline crew flying NW of the volcano at an altitude of 13 km saw the resulting ash cloud and sent the following information to the Anchorage Air Route Traffic Control Center: "Ash cloud 30 miles [48 km] NW of PSN [position], ash cloud F430 [13 km a.s.l.] then it steps down F400 [12 km] then lower F340 [10 km] right toward Mt. Klyuchevskoy[.] Aircraft deviated 50 miles [80 km] east to get around ash cloud. Ash cloud appears to be decreasing." The crew also reported "ash fallout."

For reporting, the crew used the Volcanic Activity Reporting form (in Appendix 2 of the U.S. Federal Aviation Administration's Aeronautical Information Manual, 9 February 2012). The above-mentioned completed form was sent to the Bulletin's staff on 18 November. The International Civil Aviation Organization (ICAO) has proposed the use of a similar form. We encourage flight crews to complete one of these two forms when detecting an ash cloud and send it to the appropriate government agency; we also encourage U.S. and international government agencies to send these completed forms to us for use in preparing Bulletin reports.

Table 14. Plume characteristics during 12 February 2010-14 November 2013. Key: G&S is gas-and-steam, G&A is gas-and-ash, G&S (A) is gas-and-steam with a small amount of ash, -- is not reported. Frequently, cloud cover prevented observations. Data do not include low-rising emissions. Courtesy of KVERT, Tokyo VAAC, KEMSD, and Yelizovo Airport (UHPP).

Table 15. KVERT Aviation Color Code levels. Courtesy of KVERT.

A video of the Kliuchevskoi eruption during October 2013 taken by photographer Martin Rietze and uploaded by Gregg Morgan can be observed at http://www.telegraph.co.uk/news/worldnews/europe/russia/10415179/Eruption-of-Russias-Kliuchevskoi-volcano-filmed-in-timelapse.html.

Geological Summary. Klyuchevskoy (also spelled Kliuchevskoi) is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m elevation. The morphology of the 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.

Information Contacts: Kamchatka Volcanic Eruptions Response Team (KVERT), Far East Division, Russian Academy of Sciences, 9 Piip Blvd., Petropavlovsk-Kamchatsky, 683006, Russia (URL: http://www.kscnet.ru/ivs/); Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/); Yelizovo Airport (UHPP),(URL: http://www.airport-pkc.ru/); Associated Press (URL: http://www.ap.org/); Itar-Tass (URL: http://tass.ru/); Kamchatka Travel (URL: http://www.travelkamchatka.com /); and NASA Earth Observatory, EOS Project Science Office, NASA Goddard Space Flight Center, Goddard, Maryland, USA (URL: http://earthobservatory.nasa.gov/).