Bulletin of the Global Volcanism Network
Bulletin of the Global Volcanism Network (April 2013)
All information contained in these reports is preliminary and subject to change.
This file contains all of the reports for this month. Select "Table of Contents" for links containing all Smithsonian reports for each volcano.
Active lava flows and ash emissions during October 2011-May 2013
Dome growth and volcanic activity continues
Near continuous tremor between July 2012 and March 2013
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
30 August 2010-Two simultaneous ash plumes from adjacent vents
Microearthquakes leading to January 2013 explosions ending 18 month calm
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
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.
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).
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).
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 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.
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.
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, Petropavlovsk-Kamchatsky, 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@example.com, 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/).
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.
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.
Date(s) Plume altitude Plume drift/direction (plumes <8 km) (drift <100 km) 11-18 Mar 11 3.8-8 km 312 km/W & NW 18-20 Mar 11 5.8 km 373 km/SE and N 01-05 Apr 11 7.5 km 187 km 22-27 Apr 11 6.7 km 153 km/N; 400 km/SE 01 May 11 4.5 km 124 km/NE 05-07 May 11 3-7.5 km 196 km/N 29-31 May 11 7.6-10 km 1,000 km/S-SW 04-06 Jun 11 6.1-9.1 km 734 km/SE 15 Jun 11 10 km 26 km/NW 19-21 Jun 11 10 km 176 km/nr 23 Aug 11 8.2 km nr/nr 28-31 Aug 11 6.1-8.6 km nr/E & NE 11 Sep 11 10.3 km nr/nr 03-08 Oct 11 6-9 km 160 km/NE 13-18 Oct 11 8-10.5 km 75 km/E 21-25 Oct 11 7.1-10.6 km 170 km/SE 25-28 Mar 12 7 km 192 km/E & SE 29 Mar-03 Apr 12 6.6 km 114 km/W,E, & NE 14-18 Apr 12 4-7.5 km 120 km/N, NE, & E 24 Apr 12 10 km 396 km/NE 01 May 12 5 km 270 km/NE 05 May 12 10 km 800 km/SE 12 May 12 8 km 800 km/E 19-20 May 12 9.1-9.5 km 410 km/SW 25-30 May 12 9 km 555 km/SW, SE, & E 02 Jun 12 9.1 km 250 km/S 05-06 Jun 12 8-8.2 km nr/nr 15 Jun 12 8.2 km nr/nr 24 Jun 12 5.2-9.8 km nr/nr 27 Jul 12 10.1 km nr/nr 06-11 Apr 12 7.7 km 210 km/SW & SE 18-20 Sep 12 8 km 2,000 km/SE 04-06 Oct 12 6-7 km 360 km/SE 04-06 Mar 13 7-9 km 200 km/SE 10 Jun 13 7-8 km 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.
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).
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).
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).
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.
Month Earthquakes Tremor duration Max plume height (hours:minutes) (m above crater rim) Other activity Jul 2012 29 A-type events, 38:5 400 123 B-type events Eruption. Aug 2012 17 A-type events, 0:0 (or 0:1)* 300 39 B-type events (or 60 events)* No eruption. Plume on 19 Aug only. 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 -- 744:0 500 White plumes 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. Mar 2013 -- -- 500 Tremor data unavailable. 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/ ).
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.
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."
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).
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.
Date Deep Shallow Local Long-distance volcanic volcanic tectonic tectonic (VA) (VB) (TL) (TJ) 27 Dec 2012 4 1 3 -- 28 Dec 2012 8 -- -- 3 29 Dec 2012 5 -- 2 1 30 Dec 2012 2 -- -- 1 31 Dec 2012 14 -- 3 3 01 Jan 2013 14 -- 6 3 02 Jan 2013 8 -- 5 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).
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).
19.514°N, 103.62°E; summit elev. 3,850 m
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 effusive-to-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.
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 microearthquakes (pulgas) occurred preceding the largest explosive events. This is shown in the 6 January seismic data presented in figure 14.
Figure 15 shows the 29 January explosion as viewed from video station Nevado installed 5.3 km N of Colima's crater.
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).
Date Energy, J 06 January 2013 7.2 x 10^10 13 January 2013 2.3 x 10^10 29 January 2013 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)).
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 GuzmÃ¡n, 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 BretÃ³n, 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, GonzÃ¡lez, M, Macedo, O and BretÃ³n, M, 2010, Swarms of microearthquakes associated with the 2005 Vulcanian explosion sequence at VolcÃ¡n 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).
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).
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 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).|
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 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.
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 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).
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]
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).
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.
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.
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).