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Report on Sheveluch (Russia) — August 2017


Sheveluch

Bulletin of the Global Volcanism Network, vol. 42, no. 8 (August 2017)
Managing Editor: Edward Venzke. Research and preparation by Paul Berger.

Sheveluch (Russia) Ash explosions, pyroclastic flows, and lava dome growth continues through July 2017

Please cite this report as:

Global Volcanism Program, 2017. Report on Sheveluch (Russia) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 42:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN201708-300270



Sheveluch

Russia

56.653°N, 161.36°E; summit elev. 3283 m

All times are local (unless otherwise noted)


An eruption at Sheveluch has been ongoing since 1999, and recent activity there was previously described through February 2016 (BGVN 42:03). During March 2016-July 2017, the same type of activity prevailed as before, consisting of lava dome growth, explosions, and pyroclastic flows. The following data comes from Kamchatka Volcanic Eruption Response Team (KVERT) reports. During this period the Aviation Color Code (ACC) remained at Orange (the second highest level on a four-color scale), except for a brief period on 10 December 2016 and brief periods during May-July 2017 when it was Red (highest level).

Activity during March 2016-April 2017. According to KVERT, ongoing activity during March 2016-April 2017 consisted of lava-dome extrusion onto the N flank accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images detected an intense daily thermal anomaly over the dome.

On 18 September 2016, a moderate explosion caused dome collapse and 10-km-long pyroclastic flows. Pyroclastic-flow deposits were noted in the Baydarnaya (also spelled Baidarnaya) River valley to the SSW and in the central part of the S flank.

Ash plumes generated by explosions and re-suspended ash usually occurred several times per month, and generally reached altitudes of 4.5-7 km. On 10 December 2016, explosions generated ash plumes observed in satellite images that rose to altitudes of 10-11 km and drifted 910 km NNE. The ACC was raised to Red. By the following day, no further ash emissions were observed, and the ACC was lowered back to Orange. However, explosions continued in December that sent ash plumes as high as 7 km altitude (figure 42). Typical activity continued through the first few months of 2017, including ash explosions sending plumes to as high as 5-6 km altitude (figure 43) that remained visible in satellite imagery 100 km downwind.

Figure (see Caption) Figure 42. Explosions from Sheveluch sent ash up to 7 km altitude at 2314 UTC on 19 December 2016. Photo by Yu. Demyanchuk; courtesy of Institute of Volcanology and Seismology FEB RAS, KVERT.
Figure (see Caption) Figure 43. Typical activity from Sheveluch is evident on 16 April 2017, with an ash plume rising to around 4 km altitude. Photo by Yu. Demyanchuk; courtesy of Institute of Volcanology and Seismology FEB RAS, KVERT.

Activity during May-July 2017. Beginning In May 2017, explosive activity appeared to intensify. Strong explosions on 12 May 2017 generated ash plumes identified in satellite images that rose to altitudes of 9-10 km, spread 70 km wide, and drifted 115 km NW. The ACC was raised to Red. Pyroclastic flows descended the flanks and produced ash plumes that rose 3.5-4 km and drifted NE. A few hours later, satellite images showed a thermal anomaly but no ash emissions, and the ACC was lowered back to Orange.

According to KVERT, after a series of explosions during 13-14 May (figure 44), powerful explosions on 16 May generated ash plumes that rose 8-11 km in altitude, prompting an increase of the ACC to Red. Pyroclastic flows descended the S flank, producing ash plumes that rose 3.5-4 km in altitude (figure 43) and drifted NE; within a few hours, satellite images did not show any ash emissions; the ACC was lowered to Orange.

Figure (see Caption) Figure 44. Ash plumes rise from explosive activity and pyroclastic flows at Sheveluch on 14 May 2017, seen here to an altitude of about 5 km. Photo by Yu. Demyanchuk; courtesy of Institute of Volcanology and Seismology FEB RAS, KVERT.

Additional explosions occurred 18 May. During 23-25 May 2017 powerful explosions generated ash plumes that rose to an altitude of 8 km and drifted 715 km in different directions. On 25 May, at 0830, explosions generated ash plumes that rose to an altitude of 9-10 km and drifted 16 km NE. The ACC was raised briefly to Red. Within the next 90 minutes, the ash plume was identified in satellite images drifting 82 km ENE. Strong steam-and-gas emissions rose from the lava dome. The ACC was lowered back to Orange.

KVERT reported that during the last week of May and first half of June, powerful explosions generated ash plumes that rose 8 km in altitude and drifted 550-1,554 km in various directions. Pyroclastic flows traveled 10 km. Ashfall was reported in Klyuchi Village (50 km SW) on 8 June.

On 15 June, at 0425, powerful explosions generated ash plumes that rose as high as 12 km altitude (figure 45). The ACC was raised to Red, and then back down to Orange by the end of the day. Ash plumes drifted 1,000 km NE and SW during 15-16 June. Ash fell in Klyuchi (50 km SW), Maiskoe, Kozyrevsk (115 km SW), and Atlasovo (160 km SW).

Figure (see Caption) Figure 45. Photo of an ash cloud from Sheveluch generated by a powerful explosion that began at 1625 UTC on 14 June 2017. Photo by A.V. Voznikov; courtesy of the Institute of Volcanology and Seismology FEB RAS, KVERT.

According to KVERT, explosions on 17, 18, and 27 June generated ash plumes that rose as high as 7-10 km altitude and drifted as far as 1,500 km. Explosions on 2 July sent ash plumes to 10-11 km; one plume drifted 1,050 km SW and another drifted 350 km NE. On 23 July, strong explosions generated ash plumes that sailed up to 11-12 km and drifted 1,400 km E. Explosive activity the next day lasted about 8 hours and generated ash plumes that rose 11.5-12 km in altitude and drifted almost 700 km NE and 1,400 km E. Strong pyroclastic flows were also noted. The ACC was raised to Red. Later that day, only steam-and-gas emissions with a small amount of ash was observed, and the ACC was lowered to Orange.

Thermal anomalies. Thermal anomalies based on MODIS satellite instruments analyzed using the MODVOLC algorithm were frequent during the current reporting period. From 1 March to 31 August 2016 thermal anomalies were detected 11-20 days each month. The number of days each month with anomalies was lower during 1 September 2016 to 30 July 2017 (except for October with 13 days), ranging from 3 days in April and May 2017 to 10 days in March. Only one hotspot was recorded in July 2017. The MIROVA system detected numerous hotspots every month during August 2016-July 2017, most of which were about 5 km or less from the summit with very low power signatures.

Figure (see Caption) Figure 46. Thermal anomalies at Sheveluch identified on MODIS data by the MIROVA system (log radiative power) for the year ending 4 August 2017. Courtesy of MIROVA.

Geological Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.

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/kvert/); Institute of Volcanology and Seismology, Far Eastern Branch, Russian Academy of Sciences (IVS FEB RAS), 9 Piip Blvd., Petropavlovsk-Kamchatsky 683006, Russia (URL: http://www.kscnet.ru/ivs/eng/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/).