Bulletin of the Global Volcanism Network

All reports of volcanic activity published by the Smithsonian since 1968 are available through a monthly table of contents or by searching for a specific volcano. Until 1975, reports were issued for individual volcanoes as information became available; these have been organized by month for convenience. Later publications were done in a monthly newsletter format. Links go to the profile page for each volcano with the Bulletin tab open.

Information contained in these reports is preliminary at time of publication and subject to change.

 Bulletin of the Global Volcanism Network - Volume 39, Number 06 (June 2014)

Managing Editor: Richard Wunderman

Bagana (Papua New Guinea)

Eruption continues during 2011-2013; ash plumes and lava flows

Dukono (Indonesia)

Frequent minor ash plumes persist at least through July 2014

Kusatsu-Shiranesan (Japan)

Seismicity, deformation, and hydrothermal emissions during 2013-2014


Papua New Guinea

6.137°S, 155.196°E; summit elev. 1855 m

All times are local

Eruption continues during 2011-2013; ash plumes and lava flows

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Our last report discussed events at Bagana volcano into early 2011 (BGVN 36:01). One of the most active volcanoes in Papua New Guinea, in eruption since at least early 2000, Bagana is located on the mountainous spine of Bougainville Island. Bagana is far from cities and hard to reach due to the rough terrain (see location map, Figure 9, BGVN 33:11). Monitoring and reporting are often fragmentary and based on distant observers or satellite remote sensors (e.g., MODVOLC thermal alerts).

Bagana emits volcanic gases (primarily water vapor, carbon dioxide and sulfur dioxide) almost continuously, and frequently extrudes thick lava flows. According to Darwin Volcanic Ash Advisory Centre (VAAC) reports, ash plumes from Bagana since our last report in 2011 have ranged in altitude between about 2 and 4.3 km.

Figure 20 shows satellite imagery of a recent lava flow on the Bagana's E flank.

Figure 20. This natural-color image reveals a fresh lava flow on Bagana’s E flank. The image was collected by the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite on 16 May 2012. Previous imagery from Landsat 7 showed that this lava flow was emplaced between March 2011 and February 2012. The fresh lava is dark brown. Older lava flows are covered in light green vegetation, and the surrounding forests are dark green. The plume and weather clouds are both white. NASA images by Jesse Allen and Robert Simmon using EO-1 ALI data; original caption by Robert Simmon. Courtesy of NASA Earth Observatory web site.

The Papua New Guinea Department of Mineral Policy & Geohazards Management (DMPGM) reported that Bagana has been generally quiet since our previous report. Between March 2011 and February 2012, a lava flow occurred on the E flank (figure 1), and intermittent, weak emissions of thin to thick white vapor was observed. MODVOLC thermal alerts were frequent almost every month during the reporting period. Some geographical insight may serve toward a better understanding of the text below (figure 21).

Figure 21. Topographic map showing the area around Bagana volcano. The map was prepared for a 1-month community awareness program conducted by the Rabaul Volcano Observatory and the Bagana Observer newspaper. The program was focused around the Torokina area but it also covered some areas in the S and E parts of Bougainville island. Courtesy of DMPGM.

Rabaul Volcano Observatory (RVO) reported an ash eruption on 13 December 2012. Reports of light ashfall at Arawa (40 km SE of Bagana) were made, and a report of slightly thicker ashfall came from Manetai (~11 km E). No ashfall was reported at Torokina (SW).

The website Panaramio hosts several photos of Bagana taken in January 2013 looking from the W to SW. The images show a steep-sided cone with vigorous steaming coming from an extensive portion of the summit area (Tate, 2013).

During 6-12 August 2014, DMPGM reported increasing activity. Thin to thick white vapor plumes were accompanied on 6 and 8 August by reports of rockfalls. On 10 August, an ash plume rose to an estimated several hundred meters above the crater and drifted SW and W. Moderate ash was reported in Wakovi (6 km WSW), and residents were advised to evacuate to Gotana (~9 km SW of the summit) if ashfall continued. On 11 August, the Darwin VAAC reported ash plumes that rose to an altitude of 3 km and drifted up to 55 km SW. On 12 August, Darwin VAAC raised the Aviation Color Code to Red as ash plumes rose to an altitude of 7.6 km and drifted up to 167 km SW. It was lowered to Orange the next day. During 25-28 August, ash plumes rose 2.1-2.4 km in altitude.

Reference. Tate, Peter John, 2013, Two photos taken in the Autonomous Region of Bougainville, Papua New Guinea (S. Basious, photographer)(URL: http://www.panoramio.com/photo/86632789 and http://www.panoramio.com/photo/86632796 ); Panoramio-Google Maps (uploaded 26 February 2013; accessed September 2014).

Geologic Background. Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia's youngest and most active volcanoes. This massive symmetrical, roughly 1850-m-high cone was largely constructed by an accumulation of viscous andesitic lava flows. The entire edifice could have been constructed in about 300 years at its present rate of lava production. Eruptive activity is frequent and characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although explosive activity occasionally producing pyroclastic flows also occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with prominent levees that descend the volcano's flanks on all sides. Satellite thermal measurements indicate a continuous eruption from before February 2000 through at least late August 2014.

Information Contacts: Papua New Guinea Department of Mineral Policy & Geohazards Management (DMPGM), Port Moresby, Papua New Guinea; MODVOLC, Hawai'i Institute of Geophysics and Planetology (HIGP) 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/); NASA Earth Observatory (http://earthobservatory.nasa.gov/NaturalHazards); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); and Rabaul Volcano Observatory (RVO), PO Box 386, Rabaul, Papua New Guinea.



1.68°N, 127.88°E; summit elev. 1335 m

All times are local

Frequent minor ash plumes persist at least through July 2014

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Dukono, one of Indonesia's most active volcanoes, frequently ejects weak ash plumes, and our previous report summarized that activity through 13 September 2011 (BGVN 36:03). This report summarizes activity from that date through July 2014. Most of the data in this report come from the Darwin Volcanic Ash Advisory Centre (VAAC), which monitors activity through satellite remote sensing. The volcano has been in a state of near-continuous eruption since 1933. A map showing the location of Dukono can be found in BGVN 36:08.

Activity at Dukono through the reporting period was characterized by frequent weak explosions that ejected ash to altitudes usually in the range of 2.1-3 km (table 1, figure 1). Stronger explosions occurred occasionally, sending plumes to altitudes as high as 4.5 km. According to Darwin VAAC management reports, the VAAC issued 271 ash advisories for Dukono between July 2011-December 2012 and 116 advisories between January and November 2013.

Figure 5.Natural color photo taken on 28 April 2014 of an ash plume from Dukono. According to Darwin VAAC data presented in table 1, this plume was blown 65-280 km E. Image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite. Courtesy of NASA’s Earth Observatory (Jeff Schmaltz). 

MODVOLC thermal alerts for the reporting period are indicated in table 2. No alerts were issued between 14 September 2011 and 27 May 2012. The MODVOLC data indicate that the period 31 May-18 June 2012 was especially active. This is also partially reflected by the greater altitudes reached by the ash plumes during this period (table 1). The number of thermal alerts was also greater during 26 September-1 October 2012; however, the number of plumes or their heights during this period did not reflect greater volcanic activity.

Table 1. Ash plumes from Dukono based on analyses of satellite imagery and wind data between 14 September 2011 and 17 July 2014. Each date or date range represents at least one plume. No plumes were reported between 13 September 2011 (the end of the table in our previous report) and 26 September 2011. In addition, the table excludes data on numerous plumes between 30 June 2012 and 28 August 2013. Source data came aviation reports (VAAs) from the Darwin Volcanic Ash Advisory Centre.

___Date_____________Plume altitude (km)_______________________Plume drift__
27 Sep 2011		2.1					 75 km NW
5-6, 8-9 Oct		2.1-2.4					75-83 km NE, SE
22 Oct			3					110-185 km W
27 Oct-1 Nov 		2.1-2.7				 	 35-110 km W, NW, NE
3 Nov			2.1					 75 km NE
27-28 Nov		2.1					 65-110 km NW
29 Nov			2.1					 65 km NW
13-15 Dec		2.1					 55-75 km SW
30-31 Jan 2012		2.7					220 km SW
1-4 Feb 2012		2.7					 45-220 km SW
8-9 May			3					 75 km SE
18 May			3					 55 km E
25 May			4.5					 18 km SE
27-28 May		4.5					 93-130 km E, NE
28-29 May		3					 75 km NE
18 Jun			3					110 km W
19 Jun			3					 85 km W
28-29 Jun		3					 75 NE, E

30 June 2012--
28 August 2013	Interval omitted  

29, 31 Aug-
3 Sep 2013		2.4-3					 80-240 km W, NW
17 Sep			3					 45 km NE
23 Sep			3					 75 km NE
18-23 Oct		2.1-2.7					 35-150 km NE, E
18 Dec			2.1					>35 km E
24 Dec			3					 55 km N
25-27 Dec		3					 35-75 km NNW, N, SE
4-5 Jan 2014		2.1					 35-55 km SE
13-14 Jan		3					110 km NE
20-23 Jan		3					 75-157 km NE
28 Jan			4.3					140 km E
29 Jan			3.7				 	 75 km SE
31 Jan-4 Feb		2.1				 	 55-185 km S, SE, E
5-6 Feb			2.1					 55 km S, SW
9-11 Feb		2.1-4.3				 	 40-90 km NW, NE
17 Feb			3.7				 	 55 km SSW
20, 22-23 Feb		2.1					 55-150 km E, SE, SSE
1-2 Mar			3.7					 55-100 km E, SE
11 Mar			2.1					 75 km SE
14 Mar			2.1					 90-160 km NW
16-17 Mar		2.4					130-150 km SW
20-25 Mar		2.4-2.7					 45-100 km SE, E, NE
27-28 Mar		3					 65-150 km W, NW
10-13, 15-19,
21-22 Apr		1.8-2.4				 	 65-280 km SE, E
23 Apr-6 May		2.4-3				 	 35-185 km E, SE, SW, W, ESE
8-9, 12 May 		2.4					 75-110 km W, SW, WNW
24 May			3.4					 65 km W
28 May 			2.1					 75 km NW
29 May			3					 65 km W
3-4 Jun			2.1					 55-150 km N, NW
5 Jun			3.7					 55 km NW
9 Jun			1.5-1.8			 	 	 25-30 km NW
11 Jun			2.4					>35 km NE
27-28 Jun		2.1					 45-75 km NE, E
12-15 Jul		2-3					 ---- NE
17 Jul 2014		1.8					 55 km NE

Table 2. For Dukono, MODVOLC thermal alerts recorded between 14 September 2011-31 July 2014. No thermal alerts were recorded during 2011, and the next alert corresponds to the first entry in the table (28 May 2012). Courtesy of Hawai'i Institute of Geophysics and Planetology.

14 Sep 2011-27 May  2012		No  alerts
28 May 2012				1
31 May					2
02 Jun					2
09 Jun					2
10 Jun					2
14 Jun					2
18 Jun					2
15 Sep					1
26 Sep					2
01 Oct					2
26 Mar 2013				1
13 May					1
22 May					1
28 Apr 2014				1
01 Jun					1
13 Jun					1

Geologic Background. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the north-flank cone of Gunung Mamuya. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.

Information Contacts: Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); 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/); NASA Earth Observatory, EOS Project Science Office, NASA Goddard Space Flight Center, Goddard, Maryland, USA (URL: http://earthobservatory.nasa.gov/).



36.618°N, 138.528°E; summit elev. 2165 m

All times are local

Seismicity, deformation, and hydrothermal emissions during 2013-2014

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Although no eruption ensued, the Japan Meteorological Agency (JMA) reported that the Alert Level for Kusatsu-Shirane was increased on 3 June 2014 from Level 1 (Normal) to Level 2 (Near-crater warning). Concern rose owing to elevated seismicity including shallow earthquakes within a few kilometers of the surface, deformation, elevated temperatures, and more. Many of the anomalies centered at or near Yugama, the largest of the three crater lakes within the volcanic complex (figures 1 and 2). Snow melted associated with fumaroles adjacent Yugama. Yugama lake was the scene of discolored water and floating sulfur on at least two occasions during 2013-2014. Seismicity rose in March 2014; ground deformation, in April 2014; and ground temperatures, in May 2014. Volcanic tremor was absent during this reporting period of February 2013-July 2014.

Figure 1. Annotated topographic map covering Kusatsu-Shirane and the surrounding area. Circled areas correspond to three fumarolic fields: 1, N-flank fumaroles (see figure 2); 2, NE-flank fumaroles (where typically the highest temperatures were measured from the three sites); and 3, the NNE shoreline of Yugama crater lake. Area 3 was also monitored by a web camera (maintained by Tokyo Institute of Technology). The Kusatsu-Shirane visitor center is located near the red letter P. Courtesy of JMA.
Figure 2. The N-flank fumarolic region (labeled 1 in figure 1) of Kusatsu-Shirane seen at 1058 on 5 December 2013 looking S. This is an aerial photo taken from ~2,440 m altitude. Snow had melted in some areas within the dashed red ellipse. The crater lake in the middle ground is Yugama. Courtesy of JMA.

February-December 2013. JMA maintained Alert Level 1 through 2013 and fumarolic activity continued at a low level from the three zones (see figure 1). Temperatures measured with an infrared camera were typically less than 40°C. On 17 March 2013, JMA reported an increase in the number of small volcanic earthquakes with epicenters near the Yugama crater lake. Seismicity dropped back down to normal levels during April-September, and thermal activity continued at low levels.

JMA reported that seismicity was temporarily elevated in October 2013 in the area between Yugama crater lake and the Yamada-toge Pass (figure 3). Hypocentral depths were within 4 km of the surface, relatively shallow compared with previous months.

Figure 3. Map of earthquakes located during November 2012 – October 2013. Earthquakes from October 2013 are highlighted in blue, indicating that seismicity was located between the crater lake named Yugama (labled with red symbols) and a pass named Yamada-toge (~2 km NW of Yugama crater lake). Earthquake depths were within 4 km of the surface. Courtesy of JMA.

Aerial observations on 5 December 2013 determined that Yugama crater lake had two areas of cloudy water and, in one location, floating sulfur was visible on the lake surface. Figure 4 shows a photo of the lake with areas sketched in to show the approximate extent and location of where cloudy water and floating sulfur were found. Similar observations were made later, on 22 April 2014, when a cloudy area was noted during an overflight.

Figure 4. Locations of where discoloration was observed within Kusatsu-Shirane’s crater lake, Yugama, are marked on this aerial photo taken on 5 December 2013. A cloudy area as well as sulfur debris was noted. Courtesy of JMA.

Elevated seismicity during March-July 2014. During January-February 2014, up to 7 earthquakes occurred per day. An abrupt increase in seismicity was observed on 6 and 7 March 2014 when 10 and ~40 earthquakes per day respectively were recorded (figure 5). These earthquakes were centered within the area of Yugama. The note at the bottom explains the symbols refering to lake Yugama and Mount Ainomine to the lake's S. Earthquake depths were within 5 km of the surface and very clustered with few outliers (~2 earthquakes) located slightly deeper and further S. Seismicity subsided on 8 and 9 March, but during the following days, seismicity increased again and thereafter persisted for a few months. No other changes were detected from the area; diffuse white plumes continued to rise from the fumarolic zones.

Figure 5. Map and cross sections showing seismicity at Kusatsu-Shirane during 1 July 2013 through 31 July 2014. Courtesy of JMA.

Beginning in April, the GPS network registered an inflation trend across the Yugama crater region. Small-amplitude seismicity increased periodically during April-May. Ongoing magnetic surveys determined an increase in regional temperatures in May, but JMA cautioned that this characteristic was likely independent of the thermal emissions monitored at the fumarolic sites. Temperatures from the fumarolic sites had not changed significantly.

On 3 June, JMA raised the Alert Level from 1 to 2 (on a scale of 1-5) due to the ongoing seismicity, anomalous temperatures from magnetic surveys, and deformation. Gas emissions from the fumarolic sites, monitored by Tokyo Institute of Technology, changed in unspecified ways on 3 June. Warnings were announced for the immediate area of Yugama crater lake; the area within 1 km of the lake was potentially at risk if a small eruption occurred, particularly a gas explosion accompanied by ballistics. JMA recommended that no one enter the area and for any visitors to be mindful of gas hazards that could persist in low-lying areas (dense gases could collect within small valleys).

On 22 June, JMA reported the appearance of damaged vegetation; trees were dying in a forested area 3 km SW of Motoshiranesan cinder cone (location is the S-most labeled feature on the maps of figures 3 and 5). Note that Motoshiranesan is the highest peak (summit elevation: 2,176 m) belonging to the Kusatsu-Shirane complex (Hayakawa and others, 1981). An aerial survey was conducted on 23 June and observers noted that the affected area was ~10 m2. White vapor emissions with volcanic gas odors were noted and measurements from an infrared camera determined a maximum temperature of ~40°C. JMA reported that there was no apparent link between these changes and the ongoing seismicity.

In July, JMA maintained Alert Level 2 and reported that elevated seismicity continued, although tremor was not detected. More than 80 earthquakes were detected from the Yugama crater lake area on 24 and 31 July (figure 6). Fluctuations in deformation occurred and magnetic surveys indicated that regional temperatures were leveling off. Infrared camera data determined that no significant changes were occurring at the fumarolic sites. Gas emissions measured continued to suggest changes in the volcanic system.

Figure 6. For Kusatsu-Shirane, the daily number of earthquakes recorded during July 2013-July 2014. Earthquakes increased abruptly in March 2014. Two months later, JMA raised the Alert Level from 1 to 2 due to persistent unrest (see text). Note that earthquake counts exceeded the y-axis on three occasions: 5 June 2011 (86 earthquakes), 24 July 2014 (149 earthquakes), and 31 July 2014 (100 earthquakes). Courtesy of JMA.

Reference: Hayakawa, Y., Aramaki, S., Shimozuru, D., and Ossaka, J., 1981, Kusatsu-Shirane Volcano, in Aramaki, S., ed., Field Excursion Guide to Fuji, Asama, Kusatsu-Shirane, and Nantai Volcanoes: Volcanological Society of Japan, International Association of Volcanology and Chemistry of the Earth’s Interior, p. 49-63.

Geologic Background. The summit of Kusatsu-Shiranesan volcano, located immediately north of Asama volcano, consists of a series of overlapping pyroclastic cones and three crater lakes. The andesitic-to-dacitic volcano was formed in three eruptive stages beginning in the early to mid Pleistocene. The Pleistocene Oshi pyroclastic flow produced extensive welded tuffs and non-welded pumice that covers much of the east, south and SW flanks. The latest eruptive stage began about 14,000 years ago. All historical eruptions have consisted of phreatic explosions from the acidic crater lakes or their margins. Fumaroles and hot springs that dot the flanks have strongly acidified many rivers draining from the volcano. The crater was the site of active sulfur mining for many years during the 19th and 20th centuries.

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).

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 Atmospheric Effects

The enormous aerosol cloud from the March-April 1982 eruption of Mexico's El Chichón persisted for years in the stratosphere, and led to the Atmospheric Effects section becoming a regular feature of the Bulletin. Descriptions of the initial dispersal of major eruption clouds remain with the individual eruption reports, but observations of long-term stratospheric aerosol loading will be found in this section.

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 Special Announcements

Special announcements of various kinds and obituaries.

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 Additional Reports

Reports are sometimes published that are not related to a Holocene volcano. These might include observations of a Pleistocene volcano, earthquake swarms, or floating pumice. Reports are also sometimes published in which the source of the activity is unknown or the report is determined to be false. All of these types of additional reports are listed below by subregion and subject.


False Report of Sea of Marmara Eruption

Africa (northeastern) and Red Sea

False Report of Somalia Eruption

Africa (eastern)

False Report of Elgon Eruption

Kermadec Islands

Floating Pumice (Kermadec Islands)

1986 Submarine Explosion

Tonga Islands

Floating Pumice (Tonga)

Fiji Islands

Floating Pumice (Fiji)

New Britain


Andaman Islands

False Report of Andaman Islands Eruptions

Sangihe Islands

1968 Northern Celebes Earthquake

Kawio Barat


False Report of Mount Pinokis Eruption

Southeast Asia

Pumice Raft (South China Sea)

Land Subsidence near Ham Rong

Ryukyu Islands and Kyushu

Pumice Rafts (Ryukyu Islands)

Izu, Volcano, and Mariana Islands

Mikura Seamount

Acoustic Signals in 1996 from Unknown Source

Acoustic Signals in 1999-2000 from Unknown Source

Kuril Islands

Possible 1988 Eruption Plume



Aleutian Islands

Possible 1986 Eruption Plume


False Report of New Volcano




La Lorenza Mud Volcano



Pacific Ocean (Chilean Islands)

False Report of Submarine Volcanism

Central Chile and Argentina

Estero de Parraguirre

West Indies

Mid-Cayman Spreading Center

Atlantic Ocean (northern)

Northern Reykjanes Ridge


Azores-Gibraltar Fracture Zone

Antarctica and South Sandwich Islands

Jun Jaegyu

East Scotia Ridge

 Special Announcements

Special Announcement Reports