Global Volcanism Program | Bulletin of the Global Volcanism Network

Volume 38, Number 4, April 2013
Kizimen (Russia) Active lava flows and ash emissions during October 2011-May 2013
Shiveluch (Russia) Dome growth and volcanic activity continues
Suwanose-jima (Japan) Near continuous tremor between July 2012 and March 2013
Mayon (Philippines) Mainly calm during 2009-2013; 7 May 2013 explosion kills five climbers
Seulawah Agam (Indonesia) Alert Level raised due to increased seismicity in January 2013
Sinabung (Indonesia) 30 August 2010-Two simultaneous ash plumes from adjacent vents
Colima (Mexico) Microearthquakes leading to January 2013 explosions ending 18 month calm
Kilimanjaro (Tanzania) 2006 rockfall takes climbers' lives; 165 my minimum age; glacial
retreat; economic value
Zubair Group (Yemen) Eruption on new island continues into January 2012
--------------------------------------------------Editors: Rick Wunderman, Julie Herrick, Sally Kuhn Sennert, and Benjamin Andrews
Volunteer Staff: Paul S. Berger, Robert Andrews, Bruce Millar, Russell Ross, Kenneth Brown,
Jacquelyn Gluck, and Hugh Replogle
Global Volcanism Program, National Museum of Natural History, Room E-421, PO Box 37012,
Washington, DC 20013-7012 USA; Telephone: (202) 633-1800; Fax: (202) 357-2476; Email:
[email protected]; URL: http://www.volcano.si.edu/
http://www.volcano.si.edu/reports_bgvn.cfm
Kizimen
Kamchatka Peninsula, Russia
55.130°N, 160.32°E; summit elev. 2,376 m
All times are local (= UTC + 12 hours)
Significant eruptions began at Kizimen in December 2010 (BGVN 36:10) and continued through May 2013. Our previous report highlighted frequent ash
explosions, the development of a ˜2.3 km lava flow, and elevated seismicity through September 2011. In this report we continue to present data based on the
monitoring efforts of the Kamchatka Branch of the Geophysical Service of the Russian Academy of Sciences (KB GS RAS) and the Kamchatka Volcanic
Eruptions Response Team (KVERT).
Developments in data analysis based on Kizimen's 2010 eruption. The onset of activity in late 2010 provided opportunities for new methods of data analysis. Ji
and others (2013) and Senyukov (2013) highlighted distinctive precursory activity that could successfully forecast volcanic behavior. Both investigative groups
also mentioned the challenge of limited datasets for a volcanic system that recently became active without past records of geophysical data (in particular,
deformation or seismic data during a time of elevated activity). The last eruption from Kizimen occurred during 1927-1928 (Siebert and others, 2010), before
satellite or seismic monitoring (instrumentation was available in 1961) had begun.
The remote sensing investigation by Ji and others (2013) concluded that InSAR datasets from 2008 and 2010 measured > 6 cm of progressive surface
displacement in the satellite's line-of-sight before the eruption began. While "InSAR has been demonstrated to be an important tool for investigating volcanic
deformation and understanding magma supply dynamics at many of the world's volcanoes," this was the first significant deformation observed at a Kamchatka
volcanic site.
The seismic study by Senyukov (2013) detailed a new method for short-term forecasting explosive eruptions. Development for this technique began with
Bezymianny datasets and was followed by a successful application to the 2010 eruption of Kizimen using the correlation between height of ash emissions and
the integral of absolute velocity as recorded by local seismic stations.
Elevated alert status continued through May 2013.From October 2011 through May 2013, Kamchatkan authorities maintained elevated an alert status (most
frequently an Aviation Color Code of Orange) except for a few days during April-December 2012 and one day in March 2013 (figure 1). A Red level, indicating
that an "eruption is underway with significant emission of ash into the atmosphere" was announced and maintained for one day in December 2011. There were
several days of unassigned status during July-September 2012 primarily the result of station outages and meteorological conditions that inhibited observations
which are based on satellite remote sensing, a video camera, and field visits.
Figure 1. This plot of earthquakes per day at Kizimen has been annotated with Aviation Alert Levels
during the time period of October 2011 to May 2013. Blue and maroon colors alternate to distinguish each
month; green indicates approximate values that are based on the following scheme: background levels = 10
events/day, slightly above background levels = 20 events/day, and above background levels = 50
events/day. Note that during this time period, the Aviation Color Code varied between Orange and Yellow
except where noted otherwise. Data from Kamchatka Branch of the Geophysical Service of the Russian
Academy of Sciences (KB GS RAS).
Observations during October 2011-May 2013. KVERT reported in regular notifications to aviation authorities (Volcano Observatory Notification to Aviation,
VONA), that lava continued to extrude from the summit of Kizimen from October 2011 through May 2012. New notices of visual confirmation of lava
extrusion and ash plumes were released starting on 25 October 2012 and until the time of this report in May 2013 (figure 2).
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Figure 2. This natural-color NASA EO-1 ALI (Advanced Land Imager) image of Kizimen was acquired on
25 May 2013. A white plume drifted E from the summit, in high contrast with the ash-covered slopes
which appeared gray-brown. Outlined in a dashed yellow line is the lake that had formed in late 2011, now
mostly obscurred by snow and ash (see figure 13 in BGVN 36:10 for a comparison). Courtesy of NASA
Earth Observatory).
Volcano Observatory Notification to Aviation (VONA) reports were released regularly on the KVERT website covering daily and weekly activity for Kizimen
and other Kamchatka volcanoes. This reporting style was adopted by the International Civil Aviation Organization (ICAO) in 2004 "as the international warning
system for volcanic ash, becoming the first 'global standardized' VALS [Volcano Alert Level Systems]. In 2006, the USGS adopted two standardized VALS, one
for ground-based hazards and the other for aviation ash hazards, replacing extant VALS that had been locally developed at each observatory" (Fearnley and
others, 2012; Gardner and Guffanti, 2006). At the time of this report, KVERT notifications were focused on aviation ash hazards with no additional
ground-based notification system (figure 3).
Figure 3. This Kizimen VONA from 27 December 2011 highlighted observed gas-and-steam plumes,
visible effusive lava flows, and thermal anomalies. A forecast is also included as well as contact
information for additional notices and KVERT representatives. Courtesy of KVERT.
Thermal anomalies from the summit. Satellite remote sensing frequently detected elevated temperatures from Kizimen during 2011-2013 (figure 4) and a local
monitoring camera maintained by KB GS RAS detected nighttime incandescence during clear viewing conditions (figure 5).
Figure 4. MODIS/MODVOLC detected thermal anomalies from the summit area of Kizimen during
October 2011-May 2013. Note that months without anomalies may include time periods when viewing
conditions did not allow detection of elevated temperatures. Courtesy of HIGP.
Figure 5. Summit emissions and incandescence from the active flow front was visible at night on 2 March
2012 from Kizimen's E flank. Courtesy of A. Sokorenko of the Institute of Volcanology and Seismology
(FED RAS) and KVERT.
Volcanic and seismic activity peaked in December 2011 and Red Aviation Color Code was announced on 13 December when more than 220 earthquakes were
detected (figure 1). The next day, seismicity doubled and video observations showed hot avalanches from the E flank lava flow and occasional large pyroclastic
flows. During 0620-0810 a large pyroclastic flow with co-ignimbrite clouds was observed. According to the Tokyo Volcanic Ash Advisory Center (VAAC), ash
plumes rose 6.1-7.6 km a.s.l. Activity during 13-14 December generated an ash plume that extended ˜150 km E.
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FED RAS scientists conducted an aerial survey on 23 December 2011 and determined Kizimen's range of surface temperatures (figure 6). During the overflight,
temperatures were as high as 140°C, and a strong steam-and-gas plume was rising from the summit.
Figure 6. Aerial photos of Kizimen on 23 December 2011 captured the active lava flow located on the E
flank. (left image) This aerial image of Kizimen shows a lobate flow extending several kilometers from the
summit. (right image) This thermal image depicts the active margins of effusive lava flows where elevated
temperatures were concentrated; maximum temperatures were ˜140°C. Courtesy of Sergey Chirkov of the
Institute of Volcanology and Seismology (FED RAS) and KVERT.
Seismicity during October 2011-May 2013. After peaking with ˜870 earthquakes on 2 October 2011, seismicity peaked again on 20 February 2012 (651
earthquakes/day) before beginning a long period of decline until June 2012 (figure 1). Possible avalanche signals were typical during this time period and
explosion events frequently occurred. Seismicity also included spasmodic volcanic tremor, at times continuous, but more frequently intermittent episodes;
tremor became less dominant in April and was absent in May.
During May-June 2012, seismicity rarely exceeded background levels (approximately 10 earthquakes/day). Spasmodic tremor was intermittent and rarely
occurred during June-July, although an increase in tremor was detected during 24-30 July. Due to technical problems, there were data outages in July, the
majority of August, and part of September. Tremor, explosions, and possible avalanche events were detected intermittently by the seismic network in August
and September.
The seismic network detected intermittent explosive and rockfall events from October 2012 through December of that year. From October 2012 through May
2013, seismicity rarely exceeded 100 earthquakes/day. Several peaks in activity occurred in late December 2012 (a maximum of 422 earthquakes/day) and
January 2013 (a maximum of 322 earthquakes/day). Tremor, explosions, and rockfall events became more frequent in January 2013 and February. After that,
tremor became increasingly rare and was absent in May although explosion signatures were frequently-occurring throughout that time period. By May 2013,
seismicity had decreased to an average of 62 earthquakes per day.
References:Fearnley, C.J., McGuire, W.J., Davies, G., and Twigg, J., 2012, Standardisation of the USGS Volcano Alert Level System (VALS): analysis and
ramifications, Bulletin of Volcanology, 74: 2023-2036.
Gardner, C.A. and Guffanti, M.C., 2006, U.S. Geological Survey's Alert Notification System for Volcanic Activity. In: Fact Sheet 2006-3139. U.S. Geological
Survey.
Ji, L., Lu, Z., Dzurisin, D., Senyukov, S., 2013, Pre-eruption deformation caused by dike intrusion beneath Kizimen volcano, Kamchatka, Russia, observed by
InSAR, Journal of Volcanology and Geothermal Research, 256, 87-95.
Senyukov, S.L., 2013, Monitoring and Prediction of Volcanic Activity in Kamchatka from Seismological Data: 2000-2010, Journal of Volcanology and
Seismology, vol. 7, no 1, 86-97.
Siebert, L., Simkin, T., Kimberly, P., 2010, Volcanoes of the World, 3rd edn. University of California Press, Berkeley.
USGS Volcano Hazards Program: Volcano Observatory Notices for Aviation (VONA), 8 June 2013, (http://volcanoes.usgs.gov/activity/vonainfo.php). Accessed
13 June 2013.
Information Contacts: Kamchatka Branch of the Geophysical Service of the Russian Academy of Sciences (KB GS RAS), Piip Ave. 9, PetropavlovskKamchatsky, 683006, Russia; Kamchatka Volcanic Eruptions Response Team (KVERT), Institute of Volcanology and Seismology, Russian Academy of
Sciences, Far East Division, 9 Piip Blvd., Petropavlovsk-Kamchatsky 683006, Russia (URL: http://www.kscnet.ru/ivs/; http://emsd.iks.ru/˜ssl/monitoring
/main.htm; [email protected], http://www.kscnet.ru/ivs;); Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac
/data/ ); MODVOLC, 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://hotspot.higp.hawaii.edu/); Sergey Senukov, KB GS RAS,
Russia (URL: http://wwwsat.emsd.ru/alarm.html); NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/).
Shiveluch
Kamchatka Peninsula, Russia
56.653°N, 161.360°E; summit elev. 3,283 m
All times are local (= UTC + 12 hours)
Background. A summary of Shiveluch volcano was included in a paper by Van Manen and others (2012). It noted that the activity of Shiveluch was
predominantly characterized by dome formation accompanied by strong explosions (as described by Belousov and others, 1999). After 14 years of intense
fumarolic activity, Shiveluch fed a Plinian eruption accompanied by large-scale edifice failure on 11 November 1964 (Gorshkov and Dubik, 1970). Since 1964,
at least 0.27 km3 of magma had been discharged from Shiveluch during three main phases: (1) 1980-1981, (2) 1993-1995 and (3) 2001-2004 (Dirksen and
others, 2006). An additional phase of dome extrusion, accompanied by minor explosive activity that commenced in 2006, continued at least to January 2012.
Each of these phases was associated with andesite dome growth punctuated by explosions.
A web site by KVERT (Kamchatka Volcanic Eruption Response Team) (2013) shows several years of primarily ground-based photographs of plumes from
Shiveluch volcano.
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The Institute of Volcanology and Seismology website (2013) reported that Shiveluch is noted for its unusual rocks, close to adakites, likely indicating its
position over the northern edge of the subducting Pacific plate, warmed by mantle flow (Volynets et al. 2000; Yogodzinski et al. 2001). It is one of the most
prolific explosive centers of Kamchatka, with a magma discharge of ˜36x106 tons per year, an order of magnitude higher than that typical of island arc
volcanoes (Melekestsev et al. 1991).
March 2011-May 2013. Our last issue on Shiveluch covered up to March 2011 (BGVN 36:04). Based on visual observations and analyses of satellite data,
KVERT reported that from March 2011 through at least May 2013, explosive-extrusive-effusive eruption of the volcano continued. A viscous lava flow effused
on the NW to E flanks of the lava dome, accompanied by hot avalanches, incandescence, and fumarolic activity. Satellite imagery showed a daily thermal
anomaly on the lava dome when not obscured by clouds. The Aviation Color Code remained at Orange except for a few days in October 2011.
In Table 1 we include several representative cases where possible plumes (steam and/or ash) of larger sizes were documented during the last 2 years.
Measurements were made by ground observers or from satellite images; in many cases, cloud cover over several weeks or months presumably excluded
observations. In addition, the KVERT reports contain many unexplained time gaps for description of the plume.
Table 1.Representative cases of occurrence of reported possible plume altitude in excess of 8 km and/or plume drift greater than 100 km during the period
March 2011-June 2013; "nr" = not reported. It should be noted that the distances based on observations are probably accurate to no more than ˜1-2 km.
International flights were rerouted on 28-31 August 2011. The Aviation Color code was raised to Red, then lowered to Orange during 3-8 October 2011.
Courtesy of KVERT and Tokyo Volcanic Ash Advisory Center (VAAC).
Date(s)
11-18 Mar
18-20 Mar
01-05 Apr
22-27 Apr
01 May 11
05-07 May
29-31 May
04-06 Jun
15 Jun 11
19-21 Jun
23 Aug 11
28-31 Aug
11 Sep 11
03-08 Oct
13-18 Oct
21-25 Oct
25-28 Mar
29 Mar-03
14-18 Apr
24 Apr 12
01 May 12
05 May 12
12 May 12
19-20 May
25-30 May
02 Jun 12
05-06 Jun
15 Jun 12
24 Jun 12
27 Jul 12
06-11 Apr
18-20 Sep
04-06 Oct
04-06 Mar
10 Jun 13
11
11
11
11
11
11
11
11
11
11
11
11
12
Apr 12
12
12
12
12
12
12
12
13
Plume altitude
(plumes <8 km)
Plume drift/direction
(drift <100 km)
3.8-8 km
5.8 km
7.5 km
6.7 km
4.5 km
3-7.5 km
7.6-10 km
6.1-9.1 km
10 km
10 km
8.2 km
6.1-8.6 km
10.3 km
6-9 km
8-10.5 km
7.1-10.6 km
7 km
6.6 km
4-7.5 km
10 km
5 km
10 km
8 km
9.1-9.5 km
9 km
9.1 km
8-8.2 km
8.2 km
5.2-9.8 km
10.1 km
7.7 km
8 km
6-7 km
7-9 km
7-8 km
312 km/W & NW
373 km/SE and N
187 km
153 km/N; 400 km/SE
124 km/NE
196 km/N
1,000 km/S-SW
734 km/SE
26 km/NW
176 km/nr
nr/nr
nr/E & NE
nr/nr
160 km/NE
75 km/E
170 km/SE
192 km/E & SE
114 km/W,E, & NE
120 km/N, NE, & E
396 km/NE
270 km/NE
800 km/SE
800 km/E
410 km/SW
555 km/SW, SE, & E
250 km/S
nr/nr
nr/nr
nr/nr
nr/nr
210 km/SW & SE
2,000 km/SE
360 km/SE
200 km/SE
nr/nr
As shown on the table, on 5 October 2011, KVERT reported that the current Aviation Color Code for Shiveluch was Red. Activity of the volcano began to
increase from 3 October. Ash plumes rose up to 6.0-9.0 km on 3-5 October. According to visual data, a bright incandesce of the lava dome was observed over
several hours. Satellite data showed a large thermal anomaly over the lava dome, and strong explosive events could occur in near time. On 6 October 2011, the
Aviation Color Code was reduced to Orange. Explosive-extrusive eruption of the volcano continued. New lava extruded at the lava dome after strong explosions
on 3-5 October, and moderate seismic activity of the volcano continued. On 5-6 October, ash plumes rose up to 4.5-5.0 km. Ash plumes drifted to the NE from
the volcano. Satellite images showed that the large thermal anomaly continued over the lava dome.
A rather interesting pair of satellite images were collected on 6 October 2012 (figure 7). The first image image captured Shiveluch just before an exuption; the
second, 2 hours later, showed an eruption plume drifting away from the volcano. The MODVOLC Hot Spots web site showing Modis satellite thermal alerts
measured no alert during this 6 October event.
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Figure 7. When NASA's Terra satellite passed over Russia's Kamchatka Peninsula at noon local time (0000
UTC) on 6 October 2012, Shilveluch Volcano was quiet (top image). By the time NASA's Aqua satellite
passed over the area two hours later (bottom image), the volcano had erupted and sent a plume of ash over
the Kamchatskiy Zaliv. The plume traveled about 90 kilometers toward the SSE, where a change in wind
direction began pushing the plume toward the E. On 6 October, the Kamchatka Volcanic Emergency
Response Team (KVERT) reported that the ash plume from Shiveluch reached an altitude of 3 kilometers
above sea level, and had traveled some 220 kilometers from the volcano summit. This was not the first
time that MODIS observed a Shiveluch eruption shortly after it started. In 2007, MODIS captured an
image within minutes of the eruption's start, before winds could blow the ash away from the summit.
NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC. Caption by
Michon Scott.
On 4 March 2013, a single explosion ejected an ash plume up to 7 km. Strong collapses of hot avalanches from the lava dome occurred on 6 March, and
resulting ash plumes rose up to 5 km and extended about 200 km SE of the volcano. An explosion on 5 April observed by video generated an ash plume that
rose to altitudes of 5.5-6 km (figure 8).
Figure 8. (Left) Quiet winds on 3 April 2013 allowed a plume of gas and ash to remain above and near
Shiveluch. This false-color (near infrared, red, and green) image was collected by the Advanced
Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on the Terra satellite. Looking at the
land surface, snow is white; ash, light brown, and volcanic debris, dark brown. (Right) A broader view on
the same day of Shiveluch (upper right) and some adjacent volcanoes, including Bezymianny, Tolbachik,
and Kizimen, all seen in eruption on high resolution versions of this image. A fourth volcano,
Klyuchevskaya (synynom of Klinchevoskoi) emitted a small plume. Image courtesy of NASA Earth
Observatory with credit to Jesse Allen and Robert Simmon (who used data from the NASA/GSFC
/METI/ERSDAC/JAROS and the U.S./Japan ASTER Science Team).
References: Belousov, A.B., 1995, The Shiveluch volcanic eruption of 12 November 1964-explosive eruption provoked by failure of the edifice, Journal of
Volcanology and Geothermal Research, v. 66, pp. 357-365.
Belousov, A., Belousova, M., and Voight, B., 1999, Multiple edifice failures, debris avalanches and associated eruptions in the Holocene history of Shiveluch
volcano, Kamchatka, Russia, Bulletin of Volcanology, v. 61, no. 5, pp. 324-342.
Dirksen, O., Humphreys, M.C.S., Pletchov, P., Melnik, O., Demyanchuk, Y., Sparks, R.S.J., and Mahony, S., 2006, The 2001-2004 dome-forming eruption of
Shiveluch volcano, Kamchatka: observation, petrological investigation and numerical modelling, Journal of Volcanology and Geothermal Research, v. 155,
issue 3-4, pp. 201-226.
Gorshkov, G.S. and Dubik, Y.M., 1970, Gigantic directed blast as Shiveluch volcano (Kamchatka), Bulletin of Volcanology, v. 34, no. 1, pp. 261-288.
Institute of Volcanology and Seismology, 2013, Holocene Kamchatka volcanoes - Shiveluch, Global Volcanism Program number 1000-27, Kamchatka, Russia
(URL: http://www.kscnet.ru/ivs/volcanoes/holocene/main/textpage/shiveluch.htm ).
KVERT, 2013, Current activity of the volcanoes, (URL: http://www.kscnet.ru/ivs/kvert/current_eng.php?pageNum_img=1&name=Sheveluch ).
Melekestsev, I.V., Volynets, O.N., Ermakov, V.A., Kirsanova, T.P., and Masurenkov, Yu.P., 1991, Shiveluch volcano. In: Fedotov, S.A., and Masurenkov, Yu.P.
(eds) Active volcanoes of Kamchatka. V. 1. Nauka, Moscow, pp 84-92 [in Russian, summary in English].
Ponomareva, V.V., Pevzne,r M.M., and Melekestsev, I.V., 1998, Large debris avalanches and associated eruptions in the Holocene eruptive history of Shiveluch
volcano, Kamchatka, Russia. Bulletin of Volcanology, v. 59, no. 7, pp. 490-505.
van Manen, S.M., Blake, S., and Dehn, J., 2012, Satellite thermal infrared data of Shiveluch, Kliuchevskoi, and Karymsky, 1993-2008: effusion, explosions and
the potential to forecast ash plumes, Bulletin of Volcanology, v. 74, pp. 1313-1335 (DOI 10.1007/s00445-012-0599-8).
Volynets, O.N., Babanskii, A.D., and Gol'tsman, Y.V., 2000, Variations in isotopic and trace-element composition of lavas from volcanoes of the Northern
group, Kamchatka, in relation to specific features of subduction, Geochemistry International. v. 38, no. 10, pp. 974-989.
Yogodzinski, G.M., Lees, J.M., Churikova, T.G., Dorendorf, F., Woerner, G., and Volynets, O.N., 2001, Geochemical evidence for the melting of subducting
oceanic lithosphere at plate edges, Nature, v. 409, 25 January, pp. 500-504.
Information Contacts: Kamchatkan Volcanic Eruption Response Team (KVERT) (URL: http://www.kscnet.ru/ivs/kvert/index_eng.php); Tokyo Volcanic Ash
Advisory Center (VAAC); NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=80830).
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Suwanose-jima
Ryukyu Islands, Japan
29.635°N, 129.716°E; summit elev. 799 m
All times are local (= UTC + 9 hours)
This report discusses Suwanose-jima (figure 9) during July 2012 through April 2013, an interval with generally abundant tremor, low numbers of earthquakes,
weak plumes (less than 0.7 km above the crater rim), and occasional intermittent eruptions. Our previous report on Suwanose-jima discussed seismicity through
June 2012 that included volcanic earthquakes and tremor, minor explosions, and plumes which occasionally deposited ash on nearby Toshima village as late as
June 2012 (BGVN 37:08).
Figure 9. Satellite image showing the location of Suwanose-jima. Courtesy of Google Earth.
Recent monthly reports of volcanic activity from the Japan Meteorological Agency (JMA) translated into English resumed in October 2010. Since June 2012,
English-translated JMA reports on Suwanose-jima were available online every month through March 2013
According to JMA, seismic activity at Suwanose-jima remained at low levels between July 2012 and March 2013. Although explosive eruptions have occurred
repeatedly in the past, no such eruption occurred during the reporting period. However, JMA reported infrequent tiny eruptions. Volcanic tremor occurred
almost continually between 28 September 2012 and March 2013. A high-sensitivity camera often detected a weak night glow during every month. No unusual
ground deformation was seen in GPS observation data. Table 2 summarizes tremor activity and other information reported by JMA.
Table 2. A compilation of data on Suwanose-jima between July 2012 and March 2013. '-' indicates data not reported. A-type earthquakes are generally
considered to have shallow focal depths; B-type earthquakes, deeper focal depths. An asterisk "*" in the earthquake column indicates that the number of events
reported for a specific month conflicts with the number reported for that same month in the sequential monthly JMA report. Data courtesy of JMA.
Month
Earthquakes
Tremor duration
(hours:minutes)
Max plume height
(m above crater rim)
38:5
400
Other activity
Jul 2012
29 A-type events,
123 B-type events
Eruption.
Aug 2012
17 A-type events,
0:0 (or 0:1)*
39 B-type events
(or 60 events)*
No eruption. Plume on 19 Aug only.
300
Sep 2012
37 A-type events,
0:1 (or 67:52)*
300-400
86 B-type events
(or 74 events)*
No eruption. White plumes. 11 Sep aerial observation spotted white
plume above Shindake crater.
Oct 2012
22 A-type events,
705:19
700
78 B-type events.
Tiny intermittent eruptions at Otake crater. According to Tokyo VAAC,
an ash plume on 3 Oct drifted SW at altitude of 3 km (i.e. 1.5 km
higher than the JMA reported). Ashfall on Toshima village, 4 km SSW
of Otake, on 2 and 5 Oct.
Nov 2012
-720:0
500-600
Tiny intermittent eruptions. Tiny amount of ashfall on Toshima village
on 25 Nov.
Dec 2012
-622:23
500
Tiny intermittent eruptions on 26th, red hot mass seen.
Jan 2013
-White plumes
744:0
500
Feb 2013
-672:0
500
M 3.6 earthquake on 19 Feb with aftershocks. Tiny intermittent eruption
on 3 Feb. Tiny amount of ashfall on Toshima village on 3 Feb.
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Mar 2013
-Tremor data unavailable.
--
500
Apr 2013
--700
Small eruption on 13 April. Tremor data unavailable.
On 8 November 2012, a field survey at Bunka crater revealed no remarkable change in the crater's shape. Infrared images showed no significant change in the
crater's temperature distribution. On 26 December 2012, an aerial observation revealed a red-hot lava mass inside Otake crater. This phenomenon has
occasionally been observed in past observations.
On 19 February 2013, a M 3.6 earthquake occurred (apparently at Suwanose-jima). The earthquake's maximum seismic intensity on JMA's scale was 3 (felt
indoors by most or all people, objects rattle and fall off tables, houses shake strongly and may receive slight damage). In addition, a swarm of ten earthquakes
(aftershocks?) with seismic intensities of 1 or greater on JMA's scale were recorded. These earthquakes caused no significant changes in surface phenomena or
tiltmeter data. Seismicity remained at low levels, with hypocenters located just beneath the Otake crater.
Information Contacts: Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp
/jma/indexe.html ); Tokyo Volcanic Ash Advisory Center (VAAC), Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/ ).
Mayon
Luzon, Philippines
13.257°N, 123.685°E; summit elev. 2,462 m
All times are local (= UTC + 8 hours)
Mayon's emissions, often small, gas-driven, ash-bearing, and without visible magmatic components, were generally minor during 2009 through early June 2013.
The summit crater released a sudden minor phreatic eruption on 7 May 2013 that would have been harmless except for the ejection of some large blocks and the
presence of dozens of climbers on the nearby upper slopes. Five died.
As previously reported, after erupting in late 2009, Mayon seismicity generally declined to baseline levels through 23 September 2011 (BGVN 36:09). This
report summarizes seismic activity from the end of the last report into early June 2013.
According to the Philippine Institute of Volcanology and Seismology (PHIVOLCS), small ground and tilt deformations observed since 2 March 2010 were
probably due to regional faulting and not magmatic intrusion. A report published by PHIVOLCS on 27 November 2012 noted that precise leveling surveys
found slight inflation of the lower N and E slopes; ground tilt changes were not fully consistent with volcanic ground deformation, but rather with incremental
motion along a nearby segment of the Philippine fault zone.
That November 2013 report also noted that steaming had waned significantly by 27 November 2012. Steaming from the crater varied, but was, by November
2012, weak and occasionally wispy. The report indicated that crater incandescence had ceased since March 2012. Sulfur dioxide emissions had decreased to
below baseline levels of 500 metric tons/day. As a result of diminished activity, PHIVOLCS decreased the Alert Level to 0 on 27 November 2012; however, the
public was reminded not to enter the 6-km-radius Permanent Danger Zone.
The next available report on Mayon indicated that a small phreatic eruption occurred on 7 May 2013 lasting in the range of 73-146 seconds. PHIVOLCS
observed that a gray-to-brown ash cloud rose 500 m above the crater and drifted WSW. Traces of ash fell in areas WNW, affecting communities up to 19 km
away. The seismic network detected a single associated rockfall event. Seismicity and gas emissions remained within background levels and indicated no
increase in activity. The Alert Level remained at 0.
Gas-driven explosion and fatalities on 7 May.PHIVOLCS posted a photo of the eruption taken at distance (figure 10). According to news reports, that 7 May
event was fatal to climbers who had ventured to half a kilometer of the summit, a point well within the 6-km-radius Permanent Danger Zone.
Figure 10. Photo taken at 0800 on 7 May 2013 of a phreatic eruption at Mayon. Dense billowy plume is
largely white with areas of brown to gray. News reports said eruptions like this were, according to
PHIVOLCS, a regular occurrence. PHIVOLCS reported this plume as 500 m tall. According to news
reports, rocks discharged by this eruption at 0800 killed five climbers and injured at least seven others in a
region close to the summit and well within an exclusionary zone. Courtesy of PHIVOLCS.
Multiple news articles (including those in Interaksyon, The Philippine Star, Associated Press, Sunstar, and GMA Network) noted that the 7 May 2013 phreatic
eruption at 0800 ejected large rocks towards climbers, killing five and injuring at least seven. A climber was quoted as saying that their team was resting when
they heard a loud rumbling and then saw falling rocks "as big as a living room." A local tour operator said "It rained like hell with stones. It was sudden and
there was no warning."
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One of the more detailed news reports, a 7 May article by Andrei Medina and Amanda Fernandez in GMA News, said that at least two groups of climbers were
on the volcano at the time of the explosion. One of those groups, 20 climbers, incurred all five fatalities. Those fatalities included 4 foreigners [Europeans] and
one Filipino tour guide.
The article said that (according to Bernardo Rafaelito Alejandro, head of the Office of Civil Defense in Bicol) the foreign nationals and their guide were about
half a kilometer from the crater when the 0800 explosion occurred. Another group, consisting of about seven climbers on another trail suffered three injuries (all
Indonesians). Other articles raised sometimes inconsistent details about the number, composure, and locations of the various groups on the volcano.
Although authorities had set the Alert Level at the lowest risk (0, at a scale reaching up to 6) at the time of the eruption, and it remained so immediately
thereafter, they had previously established the Permanent Danger Zone. In accord with this information, the article said that Albay Governor Joey Salceda said
that the mountain climbing activities of the two groups affected were unauthorized. He added the tourist guides also failed to secure a permit from the Albay
Public Safety and Emergency Management Office (APSEMO) and the Department of Tourism." The article went further to say that Bernardo Rafaelito
Alejandro, head of the Office of Civil Defense in Bicol, said there was no need to evacuate the residents near the volcano, adding such eruptions are expected
from an active volcano, and evacuation only occurs during an Alert Level 3.
An 11 May article by Cet Dematera and Celso Amo in The Philippine Star noted that the bodies of the four foreign nationals had been retrieved from Mayon's
slopes. Another climber on Mayon during the 7 May eruption, Boonchai Jattupornpong, had lost contact with fellow Thai climbers, but had survived for 4 days
by gathering rainwater. He was found, carried out, and brought to a hospital suffering burns, cuts, and a fractured arm. The composite disaster team involved in
the search, rescue, and retrieval operations after the 7 May disaster was recommended for awards and commendation, including a possible Bronze Cross medal
award or equivalent, for bravery and heroism by the Albay Provincial Governments.
Rockfalls, degassing, and incandescence. On 8 May 2013, PHIVOLCS reported that two rockfalls at Mayon had been detected within the previous 24 hours.
Seismicity remained within background levels and indicated no increase in overall volcanic activity.
On 31 May 2013, PHIVOLCS raised the Alert Level to 1 as a precaution because, during the previous 36-hours, a visible but weak and short-lived hydrogen
sulfide (H2S) emission was observed, along with a persistent incandescence. PHIVOLCS was concerned that the incandescence might reflect a steady emission
of magmatic gas. However, PHIVOLCS also noted that seismicity remained markedly low and sulfur dioxide (SO2) measurements remained below the normal
level. A ground deformation survey indicated slight edifice inflation compared to a 13 February 2013 survey.
According to PHIVOLCS, white to off-white steam plumes drifted in various directions during 5-10 June. Occasionally, bluish fumes were noted. During most
evenings during this period, PHIVOLCS observed incandescence from the crater, although cloud cover sometimes obscured the volcano. The seismic network
recorded one volcanic earthquake during 5-6 June and another one during 9-10 June. During 6-7 June, a single rockfall signal was detected.
Information Contacts: Philippine Institute of Volcanology and Seismology (PHIVOLCS) (URL: http://www.phivolcs.dost.gov.ph); InterAksyon (URL:
http://www.interaksyon.com); The Philippine Star (URL: http://www.philstar.com/); Sunstar (URL: www.sunstar.com.ph).
Seulawah Agam
Sumatra, Indonesia
5.448°N, 95.658°E; summit elev. 1,810 m
All times are local (= UTC + 7 hours)
Seulawah Agam (also known as Seuleuwah Agam) volcano, one of three active stratovolcanoes in the Aceh province (>5 million inhabitants), is located at the
NW tip of Sumatra. Seulawah Agam has two craters, van Heutsz (Heszt), the most active crater at an elevation of 714 m on the N flank, and Simpago on the S
flank. The Indonesian Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported that activity at Seulawah Agam is generally characterized
by white plumes rising ˜1 m from the crater. Seulawah Agam has remained non-eruptive through at least 2 January 2013.
Historical data indicated that Seulawah Agam volcano last erupted 12-13 January 1839 on its NNE flank (van Heutsz crater). Prior to that, an eruption occurred
in 1510 (˜10 years), also on its NNE flank.
During April to August 2010, the seismic data suggested increased activity overall, with marginal fluctuation. On 1 September 2010, CVGHM raised the Alert
Level from I to II and restricted visitors from approaching the crater within a 3-km radius. [The 4-level Indonesian Alert Level Scale is as follows: I - Normal
(green); II - Waspada or Alert (yellow); III - Siaga or Standby (orange); and IV - Awas or Aware (red).]
During October 2010-July 2011 overall activity at Seulawah Agam decreased; seismicity, water temperature, and magmatic gas emissions decreased, but pH
measurements were stable and no significant changes at the surface were observed. The volcano was often shrouded in fog during this period. On 11 July 2011
the Alert Level was lowered from II to I.
Beginning on 27 December 2012 (table 3), there was an increase in deep volcanic seismicity over the course of the following week. Visual observations were
often prevented due to fog, although on 2 January 2013 scientists observed a new solfatara (a natural volcanic steam vent in which sulfur gases are the dominant
constituent, along with hot water vapor) that produced roaring noises and emissions which drifted ˜20 m out from van Heutsz Crater. On 3 January 2013 the
Alert Level was raised from I to II; then, on 11 May 2013, the Level was lowered to I.
Table 3. Daily numbers of earthquakes measured at Seulawah Agam volcano from the week 27 Dec 2012-2 January 2013. Courtesy of CVGHM.
Date
27 Dec 2012
28 Dec 2012
Deep
volcanic
(VA)
4
8
Shallow
volcanic
(VB)
Local
tectonic
(TL)
Long-distance
tectonic
(TJ)
1
--
3
--
-3
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29
30
31
01
02
Dec
Dec
Dec
Jan
Jan
2012
2012
2012
2013
2013
5
2
14
14
8
------
2
-3
6
5
1
1
3
3
4
Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro No. 57, Bandung 40122, Indonesia
(URL:http://proxy.vsi.esdm.go.id/index.php).
Sinabung
Sumatra, Indonesia
3.17°N, 98.392°E; summit elev. 2,460 m
All times are local (= UTC + 7 hours)
Our previous report on Sinabung (BGVN 36:03) discussed the decreased activity following the 27 August-September 2010 eruption (BGVN 35:07). That was
Sinabung's first confirmed Holocene eruption (although there was an unconfirmed eruption in 1881). The decrease in activity since that event prompted Center
of Volcanology and Geological Hazard Mitigation (CVGHM) to lower the Alert Level to 3 (on a scale of 1-4) on 23 September, where it remained through at
least mid-March 2011. Sinabung is the highest mountain in North Sumatra and sits 80 km NNW of the Toba caldera.
This report includes a more recently available post eruption photo (figure 11). That photo was taken from an aircraft on 13 May 2011 and posted by Johnny
Siahaan on Flickr (Siahaan, 2010).
Figure 11. Aerial photo taken 13 May 2011 showing summit area craters and deeply incised upper flanks at
Sinabung, as seen in the aftermath of the late 2010 eruption. A thin white plume rises from the summit
area. Photo posted by Johnny Siahaan.
This report also includes aspects of the eruption (Siahaan, 2010) during August-September 2010 (BGVN 35:07), including video of the Mt. Sinabung. Johnny
Siahaan's video of 30 August 2010 shows a scene with two separate ash plumes rising together (figure 12). The larger plume emitted laterally (almost
horizontally) but convection of the hot ash and gasses bent it into the vertical well out over the flank of the volcano. The other plume was initially smaller,
escaping from an adjacent but distinct area of the summit, and rising nearly vertically. The two plumes appear to merge at altitude and then bend in the wind.
What looks like an older plume in the distance near the beginning of the video rose and was strongly sheared in the wind. The "look direction" of the video was
not stated.
Figure 12. Two separate ash plumes rising from two vents at Sinabung. Photo courtesy of Johnny Siahaan's
Youtube video, 30 August 2010.
References: Siahaan, J, Image 1414, Sinabung Flickr (URL: http://www.flickr.com/photos/johnnysiahaan/5735509397/)
Siahaan, J, 30 August 2010, Mount Sinabung Eruption, Youtube video(URL: http://www.youtube.com/watch?v=dMSkvYRxLwA )
Siahaan, J, 30 August 2010, Gunung Sinabung Meletus, Youtube video (URL: http://www.youtube.com/watch?v=dMSkvYRxLwA )
Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL:
http://portal.vsi.esdm.go.id/joomla/; Camera: URL: http://merapi.bgl.esdm.go.id/aktivitas_merapi.php?page=aktivitas-merapi&subpage=kamera-g-sinabung).
(The preceeding "Camera" link is a camera aimed at Sinabung on a continuous basis).
Colima
Mexico
19.514°N, 103.62°E; summit elev. 3,850 m
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All times are local (= UTC - 6 hours)
One and a half years of calm at Colima volcano ended after explosive events starting on 6 January 2013. A sequence of January explosions cored out the
previous dome and generated pyroclastic flows that reached 2.8 km W of the dome. As discussed in our previous report (BGVN 36:03) the 1998-2011 effusiveto-explosive eruption at Colima ended in June 2011, leaving in the crater an andesitic lava dome constructed during 2007-2011 extrusions stage (eg., figure 97
of BGVN 36:03). During the subsequent 1.5 years of calm, seismicity dropped and all visible signs of dome growth ceased.
We begin with an abstract that describes the end date of the previous eruptive 2007-2011 interval: 21 June 2011. Next we present a synthesis of a new series of
eruption that started in 2013, sent to us in a report from the Colima Volcano Observatory, a report emphasizing both morphologic changes to the dome as a
result of the January 2013 explosions and the seismic record associated with those explosions. We follow that submission with information from other sources
including news coverage. Colima was the centerpiece at the recent Cities on Volcanoes meeting held in the city of Colima, Mexico in November 2012. At that
stage the volcano still remained quiet.
2011 eruption's end date. The missing ingredient in many assessments of eruptions with declining, drawn out waning stages is often the last date of eruption
prior to repose. Precise start dates are common, but end dates are not, restricting the precision of eruptive duration. Fortunately, increasing numbers of
instrument- and satellite-aided techniques have emerged to help document eruption end dates. Salzer and others (2013) used satellite InSar deformation data
coupled with a web camera to assess 21 June 2011 as Colima's final eruption in the 2007-2011 dome extrusion episode. They noted that "measuring deformation
in the region of the crater is important to determine the rate of the ongoing eruption and the stability of the dome. The latter part of their abstract follows.
"The activity in the summit region has been recorded by a video monitoring system installed by the University of Colima volcano observatory. We have
analysed the optical camera data obtained between February and June 2011 using spatial digital image correlation techniques. We show that the velocity of
dome extrusion varies strongly on a daily basis, reaching up to 3m/day, and then systematically decreased over the following months. Deformation was barely
above the detection threshold of 30cm/day in the weeks prior to June 21st, when a significant explosion occurred, removing part of the dome. Camera data
recorded after this event does not show any displacements, possibly due to the low spatial resolution of the camera data.
"In order to analyse slower deformation processes, we have acquired TerraSAR-X data in spotlight mode for ascending and descending tracks over Colima,
obtaining a high spatial resolution of up to 2 m, and a temporal resolution of up to 11 days. In combination with a high resolution digital elevation model, the
InSAR data allow the detection of modifications of the dome at a resolution that is two orders of magnitude below the detection threshold of the cameras. The
different temporal and spatial scales of deformation detectable by camera and radar monitoring (metre to centimetre, respectively), highlight the benefit of
combining these methods to observe the full range of activites at Colima. The results reveal that explosions may occur suddenly after a period of declined dome
growth."
Eruptions resume in January 2013. Figure 13(A) shows the dome as seen on 9 March 2012 in the midst of the year and a half interval of quiet when all visible
and available geophysical signs of dome growth remained absent. In contrast, figure 13(B) shows the scene after eruptions resumed, starting with explosions on
6 January 2013. There developed both a depression in the dome's summit and some large ejecta perched near that crater's rim. The photo was taken on 31
January after a sequence of explosive events on 6, 13, and 29 January.
Figure 13. (a) The lava dome that was formed in the crater of Colima volcano during the 2007-2011
activity, as seen from the air on 9 March 2012. Few if any documented changes were seen here during June
2011 and prior to the 6 January 2013 explosion. (b) A photograph taken on 31 January 2013 from a
perspective somewhat similar to the adjacent photo. The dome had resumed eruption by this time, resulting
in a restructuring of the upper part of the dome's surface morphology and a more pronounced circular
crater at the dome's crown. Large blocks prominent on the inner rim are from the new activity. Photos from
(a) Facultad de Ciencias, Universitad de Colima, and (b) taken during a flight by the Civil Protection of
Jalisco State and acquired by the Colima Volcano Observatory.
The January explosions cored out and partly destroyed the 2007-2011 lava dome. Figure 13(B) shows the new crater that was formed within this old lava dome.
The volume of this new crater was estimated at about 250,000 m3. During the explosions, a new lava dome began to grow in the new crater with an initial
eruption of ˜0.14 m3/s. The January eruptions generated pyroclastic flows that reached 2.8 km W of the dome.
No precursory volcano-tectonic earthquakes or deformation signals were recorded prior to the January sequences. On the other hand, sequences of numerous
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microearthquakes (pulgas) occurred preceding the largest explosive events. This is shown in the 6 January seismic data presented in figure 14.
Figure 14. A seismogram containing the 24 hour interval of 6 January 2013 record from a short period
instrument located 1.9 km from Colima's crater (vertical lines show 1 min time intervals; horizontal lines
correspond to local time zone at left and UTC at right). Note the abundance of microearthquakes of many
sizes prior to the explosion. After that explosion, microearthquakes in this amplitude range essentially
ceased during the rest of the day. Courtesy of Colima Volcano Observatory.
Figure 15 shows the 29 January explosion as viewed from video station Nevado installed 5.3 km N of Colima's crater.
Figure 15. Image made during the explosion of 29 January 2013 from Nevado station N of the crater.
Incandescent material has splashed over much of the visible dome surfaces. A dark cauliflower-shaped
cloud rose above the summit. Courtesy of Colima Volcano Observatory.
Seismic comparisons. The largest of the explosions in the January eruptive sequence can be compared from seismic records. As noted above, the associated
eruptions generated small pyroclastic flows.
Table 4 shows the energy associated with each of the eruptive pulses (6, 13, and 29 January). These results were estimated from the broadband seismic record
measured at a distance of 4 km from the crater using the methods described in (Zobin and others, 2009, 2010).
Table 4. Energy of Colima's three largest explosions during January 2013. Courtesy of Colima Volcano Observatory.
Date
06 January 2013
13 January 2013
29 January 2013
Energy, J
7.2 x 10^10
2.3 x 10^10
1.5 x 10^11
Figure 16 provides another look at Colima seismic data during January 2013. On the upper two of the three plots (A and B), dates of the three explosions (on the
6th, 13th, and 29th) are indicated as black downward pointing arrows and the key to the seismic signals is shown. Figure 16(A) shows the number of
microearthquakes, with in all three cases numbers of events increasing with approach to the explosions. For the first two eruptions, the peaks in
microearthquakes coincided with the eruption. For the third microearthquake, on the 29th, counts rose rapidly and peaked prior to the eruption. The counts
decreased after the eruption (figure 16(B)).
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Figure 16. Plots of seismicity and energy associated with Colima's explosive sequence of January 2013. (A
and B) Variations with time in the number of events recorded by a highly sensitive broadband station 1.9
km from the crater. Arrows in A and B show the appearance of three large explosions. (A)
Microearthquakes plotted here resulted from processing, where the seismic records were filtered between 1
and 50 Hz to better see seismic events of high frequency and small amplitude. (B) The number of seismic
signals indicative of small explosions, rock falls, and pyroclastic density currents. Several peaks
occurred-some coincident and others not coincident with the three marked explosions. (C) A plot of log
number of events versus log energy to compare the energy of the three largest explosions of the January
2013 sequence (colored, up-pointing arrows) with the computed energy distributions of the small and large
explosive events recorded during the 2005 explosive stage. Courtesy of Colima Volcano Observatory.
Figure 16(B) indicates that there were multiple seismically inferred explosions, on the three noted days, as well as on other days. For example, starting at left on
Figure 16(B) one sees a progression from the 6th, 1 explosion; to the 10th and 11th, 1 and 2 explosions respectively. The largest number shown was associated
with the arrow indicating the explosion on the 29th, 5 explosions, in a sequence escalating to 7 on the 31st (last data on the plot).
Figure 16(C) plots the energy of the three largest explosions of the January 2013 sequence (at the tips of the colored arrows aiming upwards). The two other
fields on the plot show the energy distributions of small and large explosive events recorded during 2005 at Colima (Zobin and others, 2010). Thus, figure 15(C)
shows that, for events assessed at Colima and in terms of seismically detected energy, the 2013 events may be considered as small to intermediate in size.
News reports. According to news articles, a scientific advisory committee reported the 6 January 2013 eruption from Colima, saying that it ejected tephra and an
ash plume that rose ˜2 km above the crater. Ash fell on residents near Ciudad Guzmán, tens of kilometers NE of the volcano. Visitors were evacuated from the
Nevado de Colima national park, which contains both Nevado de Colima and the active Volcan de Colima.
During the explosion of 29 January, residents up to 20 km away reported a loud noise, shaking ground, and rattling windows. Colima ejected incandescent
material. According to the Washington Volcanic Ash Advisory Center (VAAC), on the 29th an ash plume rose ˜2.5 km above the crater. Based on analyses of
satellite imagery, the VAAC reported that the ash plume drifted 55 km NE at an uncertain altitude to a distance of 150 km from the volcano.
References: Salzer , J, Walter , T, Legrand , D, Breton , M, and Reyes , G, 2013, Multiscale deformation monitoring at Colima Volcano using TerraSAR-X
interferometry and camera observations, EGU General Assembly Conference Abstracts (2013), vol. 15, pp. 9290.
Zobin, VM, Reyes, GA, Guevara, E, 2, and Bretón, M, 2009, Scaling relationship for Vulcanian explosions derived from broadband seismic signals, J.
Geophys. Res., vol. 114, B3, March 2009. DOI: 10.1029/2008JB005983.
Zobin, VM, Melnik, O E, González, M, Macedo, O and Bretón, M, 2010, Swarms of microearthquakes associated with the 2005 Vulcanian explosion
sequence at Volcán de Colima, México. Geophysical Journal International, vol. 182, issue 2, pp. 808-828. doi: 10.1111/j.1365-246X.2010.04647.
Information Contacts: Observatorio Vulcanologico de la Universidad de Colima (Colima Volcanological Observatory), Calle Manuel Payno, 209 Colima, Col.,
28045 Mexico (URL: http://www.ucol.mex/volc/);Facultad de Ciencias, Universidad de Colima; Washington Volcanic Ash Advisory Center (VAAC), NOAA
Science Center Room 401, 5200 Auth road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/VAAC).
Kilimanjaro
Tanzania
3.07°S, 34.35°E; summit elev. 5,895 m
All times are local (= UTC + 3 hours)
We offer our first Bulletin report on Mount Kilimanjaro, which remains a dormant volcano. We first discuss its economic value and setting. We next mention a
few of the many studies of seismically detected rockfalls at volcanoes. We next discuss a 4 January 2006 rockfall that took three climbers' lives and injured five
others (Kikoti and others, 2006). An investigation looked into the accident's location and cause, improvements to the route to minimize rockfall risk, as well as
further recommendations and implementation to make this approach to the summit safer. Although accidents due to rockfalls and mass wasting are common in
mountainous areas, volcanoes included, this subject has not typically been a major focus of Bulletin reporting. This unusually well-documented case illustrates
several approaches to mitigating similar hazards at more than just this volcano.
The next section of this report notes diminishing glacial ice on Kilimanjaro, 85% gone since 1912. The youngest age date of volcanic material on the volcano is
165,000 +/- 5,000 ybp. No evidence of younger eruptions was found in studies of glacial ice on the volcano (Kimberly Casey, personal communication, June
2013).
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There were several reports discussing the rockfall incident and future steps that might make the route safer. The report by Kikoti and others (2006) was issued
after inspection of the Arrow Glacier area looking at various alternative routes, challenges, and recommendations and implementation.
World Heritage site and economic importance. Kilimanjaro was designated a World Heritage site in 1987. UNESCO cited Kilimanjaro as "an outstanding
example of a superlative natural phenomenon" with many endangered species. Guides are required for tours and costs can range to $5,000 per person for an
expedition to the summit (Py-Lieberman, 2008). Income from Kilimanjaro ecotourism is a principal source of foreign exchange for Tanzania. Income from
tourism overall has grown from US $65 million in 1990 to US $725 million in 2001, and then represented roughly 10% of Tanzania's gross domestic product
(World Bank/MIGA, 2002). It ranks among the world's favorite volcanoes to climb (Sigurdsson and Lopes-Gautier, 2000).
Rockfalls at volcanoes. Rockfalls represent a special kind of mass movement (mass wasting smaller than landslides) in which one or more rocks become
dislodged, enters free fall, and bounces down the ground surface. The rockfalls discussed here were unusually well documented (Kikoti and others, 2006),
spurring this report on a phenomena so common as to often elude mention. Rockfalls are a source of noise in seismic monitoring, sometimes masking small
earthquakes at depth. Rockfall signals are often counted and reported along with various types of seismic events. Rockfall signals contribute to the average
absolute amplitude of seismic signals (eg., RSAM measurements) since those measurements incorporate all the various types of seismic events, rockfall signals,
and noise (Endo and Murray, 1991; Voight and others, 1998).
Rockfalls have long been thought of as a possible means of detecting larger impending mass movements and for eruption forecasting, although problems such
as glaciers, seasonal melting cycles, precipitation, other noise sources, etc. complicate interpretations. Rockfalls may also be triggered by earthquakes.
Regarding rockfall seismic signals at Augustine stratovolcano, DeRoin and McNutt (2012) state that "The high rate of rockfalls in 2005 constitutes a new class
of precursory signal that needs to be incorporated into long-term monitoring strategies at Augustine and elsewhere." Hibert and others (2011) carried out a
detailed study of rockfalls detected seismically at Piton de la Fournaise, a large shield volcano with rockfalls down steep sided caldera walls. Bulletin editors are
currently unaware of past or current seismic monitoring at Kilimanjaro, short- or long-term, and if those records exist, whether rockfalls were important. The
rockfall case under discussion at Kilimanjaro, release of glacial deposits down a steep slope, is very unlikely to reflect a pre-eruptive event.
Setting and area of fatal rockfalls. Kilimanjaro sits on the East African rift, a N-trending structure spanning from Mozambique at the S to the Afar and Red Sea
region at the N, a distance of 3,000-4,000 km. Kilimanjaro resides in a region where the rift has branched into Eastern and Western rift segments, with
Kilimanjaro on the Eastern segment (figure 17). That branching can be seen on figure 17 traversing around Lake Victoria (Lake Nyanza).
Figure 17. (Top) Overview maps showing Eastern Africa, major features of the East African rift (the
planet's largest active continental rift), and the location of Kilimanjaro (green dot). (Middle) Annotated
satellite image (SRTM) of Kilimanjaro, where colors refer to elevation; this 90 m resolution image shows
the main morphologic features. The top map was found online (credit to Google and NASA Tera metrics);
the subsequent map and satellite image were taken from Nonnotte and others (2008). (bottom) shows a
simplified map labeling key features at Kilimanjaro. Note the volcano's elongate morphology and the
summit area (Kibu and crater of the same name) and E of the saddle, the Mawenzi peak. Figure 18 shows
two contour maps. The accident's location was at the Western Breach, a spot just W of the summit crater
and a low point on the crater's rim (yellow circle on. Figures 19 and 20 show photos of the area where the
accident occurred, a spot just below the r-shaped glacier and above Arrow Glacier camp.
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Figure 18. Two contour maps showing Kilimanjaro. Note the Kibo and Mawenzi highs. Kilimanjaro's
summit resides on Kibo's rim at Uhuru Peak (5,895 m elevation). Mawenzi is the peak to the W of Kibo
(16,900 foot summit elevation). The Western Breach (Great West breach) lies on Kibo's SW face, the area
where the fatal 4 January 2006 rockfall occurred (lower map, yellow ring). That spot on the upper map is
approximately under the right digits of the label "19340" (the summit elevation expressed in feet). Note the
large glacier and snow fields; the glacier has since receded (see below). Upper map found online without
credit to source; lower map taken from Kikoti and others (2006).
Figure 19. A photo taken with Arrow Glacier camp in the foreground and a yellow dashed line indicating
the climbers' route into Kibu's crater. Note the zone of reddish rocks along the ascent as well as the
two-pronged glacier at upper left ("r-shaped glacier"). [More details: Camp is at 03°04.580' S, 037°20.357'
E; 4,871 m elevation. Location of point of entry onto Crater: 03°04.396' S, 037°21.105' E; 5,726 m
elevation; mean gradient of slope, 38.0°; mean gradient of route, 26.0°; linear distance from Arrow Glacier
camp to Crater: 1.39 km; route distance from Arrow Glacier camp to Crater: 1.95 km.] Image and details
taken from Kikoti and others (2006).
Figure 20. Zooming in on the rockfall accident scene, which occurred slightly below Kilimanjaro's
r-shaped glacier (upper left). An annotated image appears below in another figure. Taken from Kikoti and
others (2006).
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Causes of the Accident. Extensive talus resides at the intersection between the left and right arms of the r-shaped glacier (figures 21-22). Part of this unstable
talus collapsed. Kikoti and others (2006) said that the dislodged material traveled 150 m down the slope, reaching a group of people at an estimated speed of ˜40
m/sec (144 km per hour) at the point where the climbers were struck (B, figure 20).
Kikoti and others (2006) thought the talus dislodged because of (a) melting ice freeing the loose material and destabilizing it on the steep slopes, and (b) strong
downhill winds measured at 177 km/h. The wind speed was measured by guide George Lyimo on the morning of the accident, using a wind speed gauge wrist
unit.
Lyimo survived, having left camp ˜3 hours before the accident. Based on the known conditions at the summit, the climbers would only have had on the order of
5 seconds to escape the avalanche. Besides the strong winds, the climbers also confronted snowfall and poor visibility.
Kikoti and others (2008) examined a conspicuous cavity where the recent fallen rocks were believed to have been dislodged. They estimated that 39 tons of
rocks dislodged from the cavity.
Figure 21. View from Kilimanjaro's r-shaped glacier looking downward over angular boulders of talus.
Source of deadly rockfall indicated (A) as well as the point where climbers were struck (B). The distance
from point A to point B was estimated at 150 m. Taken from Kikoti and others (2006).
Figure 22. At Kilimanjaro, the scene at the rockfall's source area. Rocks here remained unstable after the
accident, an ongoing concern (see Recommendations and implementation). Note person for scale. Taken
from Kikoti and others (2006).
Current Status of Route. The old route (figure 19) was judged unsafe due to concern over two risk zones (A and B, figure 23). Zone A hosts residual glacial
deposit at the intersection of the right and left arms of the r-shaped glacier resulting in exposure to rockfall from above. Zone B includes the crater wall and rock
tower, which could shed debris from above. Above this area, the remainder of the route is judged to be subject to no specific identifiable imminent threats.
Figure 23. Annotated photo of the route to Kibu crater. The location of the January 2006 accident
delineated with a red "X." Risk zones A and B shown as shaded areas with the likely sources of risk
indicated. One part of a proposed alternate route appears as a yellow dotted line. Courtesy of Kikoti and
others (2006).
Recommendations and implementation. Kikoti and others (2006) made principal recommendations, some of which follow. As partly seen on figure 23 (yellow
dotted line), the proposed new route traverses the rock feature known as the 'Stone Train' largely avoiding indicated hazardous zones. The route would proceed
to a handrail up the left hand edge of the Stone Train to join the rock spur adjoining the base of the crater wall at ˜5,400 m.
Many of these recommendations were adopted and a October 2008 posting on the Mt. Kilimanjaro Travel Guide (Baxter, 2008) discussed implementation,
obligations of tour operators, climbers, guides and the Park to make the route safer. These ranged from immediate steps such as asking all climbing parties to
depart Arrow Glacier camp no later than 5 a.m. to mid-term steps such as the issuance by tour companies of radio handsets for guides to communicate with
Kilimanjaro National Park Authority (KINAPA) rescue teams. As a result, the Park was directed to take immediate steps such as erecting signboards warning
visitors of rockfall dangers and put in place a rockfall protocol and ensure that all their rescue staffs are trained on how to effectively use it.
Baxter (2008) recommended investigations by further specialists (seismologists, glaciologists, geologists, meteorologists, etc.) to assess the long term future
risks associated with climate change and Kilimanjaro's altering geology and glaciology. A safety patrol team was also tasked with visiting the mountain monthly
or bi-monthly to survey and identify possible future risk areas in the light of the rapidly changing situation on Kilimanjaro.
Receding glaciers. Cullen and others (2013) discuss the time series of glacial retreat at Kilimanjaro during 1912 to 2011. They concluded that 85 per cent of the
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glacier had disappeared. Figures 24 and 25 contain satellite imagery and land-based photos presented on a NASA Earth Observatory article (Allen and others,
2012) that describes the state of summit glaciers at Kilimanjaro on 26 October 2012. Melting ice and subsequent melt-water runoff reduce confining pressure on
the magmatic system. There is evidence that such reduced pressure or loading might promote the onset of volcanism (e.g., Bay and others, 2004; Pagli and
Sigmundsson, 2008; Sigvaldason and others, 1992).
Figure 24. (Left) The Advanced Land Imager on NASA's Earth Observing-1 (EO-1 Ali) satellite acquired
the top images. Green lowlands are seen to the S, including rainforest leading upslope to alpine desert. The
summit area lacks vegetation. Note thick cloud cover to the N. Glacial ice is clearly absent in much of the
circular crater. (Right) A portion of the previous image centered over Kilimanjaro's summit emphasizes the
lack of ice fields on 26 October 2012. Labels show both northern and southern icefields and a "new rift"
discussed in text, where the ice had recently melted. Bulletin editors have added to the original Earth
Observatory figure, inserting the location of the r-shaped glacier ("r."). Courtesy of NASA Earth
Observatory.
Figure 25. Lateral views of the Northern (top) and Southern (bottom) icefields in photos taken on 25 and
27 September 2012, respectively. Tents (barely visible at far left) help define scale for the shot of the
Northern icefield. Courtesy of Kimberly Casey.
According to Allen and others (2012), during a 2012 expedition, scientists found that the northern ice field, which had been developing since the 1970s then had
a hole wide enough to ride a bicycle through. They also were able to walk on land directly through the rift (labeled on figure 24, right).
Cullen and others (2013) said that despite Mount Kilimanjaro's location in the tropics, the dry and cold air at the top of the mountain has sustained large
quantities of ice for more than 10,000 years. At points, ice has completely surrounded the crater. Studies of ice core samples show that Kilimanjaro's ice has
persisted through multiple warm spells, droughts, and periods of abrupt climate change.
Fumarolic activity occurs on the volcano, particularly in Kibu crater. Tour operator Eddie Frank (Tusker Trail) has agreed to keep a log of observed changes of
color and smell at fumaroles.
Age dates of eruptive products. Nonnotte and others (2008) discussed the youngest K-Ar age date for Kilimanjaro. Samples associated with the latest parasitic
phase (05KI41B and 03TZ42B) yield ages of 165 +/- 5 ka and 195 +/- 5 ka, respectively. "The last volcanicity, around 200-150 ka, is marked by the formation
of the present summit crater in Kibo and the development of linear parasitic volcanic belts, constituted by numerous Strombolian-type isolated cones on the NW
and SE slopes of Kilimanjaro. These belts are likely to occur above deep-seated fractures that have guided the magma ascent, and the changes in their directions
with time might be related to the rotation of recent local stress field," Nonnotte and others wrote (2008).
References: Allen, J, Simmon, R, Voiland, A., and Casey, K, 2012, Kilimanjaro's Shrinking Ice Fields, NASA Earth Observatory-Image of the day (URL:
http://earthobservatory.nasa.gov/) Posted 8 November 2012; Accesssed 14 June 2013.
Baxter, P., 2008, TANAPA Western Breach Protocol—Tanzania National Parks, Obligations and Actions Regarding the Re-opening of Western Breach Route
(Arrow Glacier), Mt. Kilimanjaro Travel Guide [posted 21 October 2008] (URL: http://www.mtkilimanjarologue.com/tanapa-western-breach-protocol).
Bay, RC, Bramall, N, and P Buford Price, 2004, Bipolar correlation of volcanism with millennial climate change, Proc Natl Acad Sci U S A. 2004 April 27;
101(17): 6341-6345. Published online 2004 April 19. doi: 10.1073/pnas.0400323101 PMCID: PMC404046
Cullen, N. J., Sirguey, P., Mölg, T. Kaser, G. Winkler, M. and Fitzsimons, S. J. , 2013.A century of ice retreat on Kilimanjaro: the mapping reloaded, The
Cryosphere Discuss., 6, 4233-4265, doi:10.5194/tcd-6-4233-2012, 2012.
DeRoin N. and S.R. McNutt, 2012, Rockfalls at Augustine Volcano, Alaska: The Influence of Eruption Precursors and Seasonal Factors on Occurrence Patterns
1997-2009. J . Volcanol. Geotherm. Res., v. 211-212, p. 61-75
Endo, E.T. and Murray, T., 1991, Real-time seismic amplitude measurement (RSAM): a volcano monitoring and prediction tool. Bulletin of Volcanology 53.7
(1991): 533-545.
Hibert, C., A. Mangeney, G. Grandjean, and N. M. Shapiro, 2011, Slope instabilities in Dolomieu crater, Réunion Island: From seismic signals to rockfall
characteristics, J. Geophys. Res., 116, F04032, doi:10.1029/2011JF002038
Kikoti, I., Nchereri, J.P., Mlay, A., Lyimo, G., Msemo, E., and Rees-Evans, J., 2006, Kilimanjaro Safety Patrol Reconnaissance Expedition, 25th-27th January
2006, An investigation to determine the cause of the Western Breach accident of 4th January 2006 and to offer recommendations for the way forward for this
route [Report completed June 2006 and posted online at (URL: http://www.yumpu.com/en/document/view/7812851/western-breach-investigation-digital-copy)
Nonnotte, P, Guilloub, H, Le Guillou, B, Benoit, M, Cotten, J, Scaillet, S, 2008, Jour. of Volc. and Geoth. Res., Volume 173, Issues 1-2, 1 June 2008, pp. 99-112
Pagli, C., and Sigmundsson, F. (2008). Will present day glacier retreat increase volcanic activity? Stress induced by recent glacier retreat and its effect on
magmatism at the Vatnajökull ice cap, Iceland. Geophysical Research Letters, 35(9), L09304.
Py-Lieberman, B, 2008, Life lists, Hiking Mount Kilimanjaro, A trek up the world's tallest freestanding mountain takes you through five different ecosystems
and offers a stunning 19,340-foot view, Smithsonian magazine, January 2008 [online version, URL: http://www.smithsonianmag.com/specialsections/lifelists
/lifelist-kilimanjaro.html]
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Sigurdsson S., and Lopes-Gautier, R. 2000, Volcanoes and Tourism; Encyclopedia of Volcanoes, Academic Press, pp. 1283-1299.
Sigvaldason, G.E., Annertz, K., and Nilsson, M., 1992, Effect of glacier loading/deloading on volcanism: postglacial volcanic production rate of the Dyngjufjöll
area, central Iceland. Bulletin of Volcanology 54, no. 5 (1992): 385-392.
UNESCO, date uncertain, Kilimanjaro National Park, UNESCO (URL:whc.unesco.org/en/list/403)
Information Contacts: Eddie Frank, Tusker Trail, 924 Incline Way Suite H Incline Village, Nevada 89451-9423 USA (URL: http://www.Tusker.com); and
Kimberly Casey, NASA Goddard Space Flight Center, Cryospheric Sciences Lab, Code 615, Greenbelt, MD 20771 USA (URL: http://neptune.gsfc.nasa.gov
/csb/personnel/?kcasey).
Zubair Group
Yemen, Red Sea
15.154°5, 42.104°E; summit elev. unknown
All times are local (= UTC + 3 hours)
In BGVN 36:11 we reported on an ongoing submarine eruption in the N portion of Yemen's Zubair group of islands in the Red Sea that began between 13 and
15 December 2011. A new island emerged in this vicinity and was large enough to resolve in satellite imagery by 23 December 2011. The latitude and longitude
given in the header for this report is for the volcanic island of Jebel Zubair (15.05°N, 42.18°E), the largest island of the Zubair Group (figure 26). The new
island emerged approximately 15.158°N, 42.101°E, or ˜10 km NW off the NW coast of Jebel Zabair. A bathymetric sketch map made in 1973 indicated a water
depth of about 100 m in that area. The S end of the new island is about 500 m NNW of Rugged Island. The Zubair group is located ˜74 km off the NW coast of
Yemen, in the S Red Sea. They are comprised of over 10 isolated uninhabited volcanic islands and rock outcrops extending NNE to SSE over an area of ˜258
km2.
Figure 26. Map and index map of the 10 islands of the Zubair Group (Yemen) showing the site of the new
eruption and its associated emergent island. Islands are represented by gray shading; other features are
identified by the legend at left. The cross section at the bottom is along line A-B through the S portion of
the group. Modified from Gass and others (1973); index map modified from MapsOf.net.
By 7 January 2012, the island had grown to about 530 x 710 m, and a gas-and-steam plume containing ash rose from a distinct cone (figure 27). A video from a
Yemeni miliary helicopter uploaded on YouTube on 2 January 2012 showed violent explosions typical of shallow submarine eruptions. The satellite image in
figure 27 shows that a new island in the Zubair Group is the source of the volcanic plume.
Figure 27. This satellite image, acquired 7 January 2012, shows that the island had risen above water. A
plume of steam, other volcanic gases, and ash rises from a distinct cone. The land surrounding the vent had
grown, and was about 530 by 710 m in dimension. Once above water, past eruptions in the Zubair Islands
were primarily effusive, with low viscosity lava forming thin lava flows. This natural-color image was
acquired by the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite. Courtesy of
NASA Earth Observatory web site; image by Robert Simmon, using ALI data from the EO-1 Team;
caption by Robert Simmon.
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Natural-color images from the Enhanced Thematic Mapper Plus (ETM+) on Landsat-7 on 15 January and 15 February 2012 show the new island, but no plume
rising from it or any other indication of eruption continuing.
MODVOLC, using data from the Aqua Modis satellite, measured a 2-pixel thermal alert at 2235 hr UTC, 11 January 2012, at latitude 15.16EN, longitude
42.10EE, just S of Haycock Island. This was the only thermal alert measured in the area during the December 2011-January 2012 time period.
References: Gass, I.G., Mallick, D.I.J., and Cox, K.G., 1973, Volcanic islands of the Red Sea. Journal of the Geological Society of London, v. 129, no. 3, pp.
275-309.
Vervaeck, A., 2012 (17 January), Surtseyan eruption along the coast of Yemen forms a new island - January 15 new ALI satellite image, Earthquake newsreport
web site (URL: http://earthquake-report.com/2011/12/29/surtseyan-eruption-along-the-coast-of-yemen-forms-a-new-island-today-eruption-cloud-stain);
accessed 21 May 2013.
YouTube video uploaded by Naif8989889 on 2 January 2012, (http://www.youtube.com/watch?v=YoMLNEJC-Nk&feature=gu&
context=G2d0c74aFUAAAAAAAAAA).
Information Contacts: NASA Earth Observatory (URL: http://www.earthobservatory.gov).
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