Activity for the week of 23 September-29 September 2009
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
New Activity / Unrest
Dieng Volcanic Complex
| Central Java (Indonesia)
| 7.2°S, 109.879°E
| Elevation 2565 m
CVGHM reported that on 26 September a "thunderous" noise from Dieng was heard from 2 km away. The next day, a phreatic eruption from an unspecified crater ejected mud as far away as 140 m S. The deposits were as thick as 10 cm near the vent and 1 cm near the farthest point. The Alert Level remained at 1 (on a scale of 1-4).
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
KVERT reported that on 17 and 22 September a weak thermal anomaly over Karymsky was detected in satellite imagery. During 19-23 September seismic activity was above background levels; analyses of the seismic data indicated that ash plumes possibly rose to an altitude of 2 km (6,600 ft) a.s.l. during 21-22 September, and to an altitude of 4.5 km (14,800 ft) a.s.l. on 23 September. Scientists flying near Karymsky in a helicopter on 22 September saw ash plumes that rose to an altitude of 1.7 km (5,600 ft) a.s.l. and drifted E. The Level of Aviation Color Code was raised to Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that during 18-25 September seismic activity from Shiveluch was above background levels. Analyses of satellite imagery revealed a large daily thermal anomaly over the lava dome. Based on interpretations of seismic data, ash plumes possibly rose to an altitude of 5.2 km (17,100 ft) a.s.l. According to video camera data and visual observations, ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. on 18, 19, and 22 September, and hot avalanches from the lava dome were noted during 18 and 22-23 September. Ash plumes were occasionally seen drifting 15-70 km N, NW, and SE. The Level of Aviation Color Code remained at Orange.
Based on information from KEMSD, the Tokyo VAAC reported that on 28 September an eruption produced a plume that rose to an altitude of 7 km (23,000 ft) a.s.l.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima during 23, 25, and 27-29 September produced plumes that rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted SW, W, and NW.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
| Komba Island (Indonesia)
| 7.791°S, 123.585°E
| Elevation 633 m
Based on analyses of satellite imagery, the Darwin VAAC reported that during 23-29 September ash plumes from Batu Tara rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 15-75 km W and NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| 42.833°S, 72.646°W
| Elevation 1122 m
Based on web camera views and analyses of satellite imagery, the Buenos Aires VAAC reported that on 28 September a diffuse ash plume from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex, possibly mixed with steam and gas, rose to an altitude of 2.4 km (8,000 ft) a.s.l. The plume drifted less than 40 km W and SW.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 24 September an ash plume from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 65 km NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 23-27 September, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Lava was not seen entering the ocean on 28 and 29 September. Visual observations and thermal anomalies detected in satellite images revealed active surface lava flows on most days. On 23 September, weak incandescence was detected from inside Pu'u 'O'o crater and from a gas vent in the E crater wall. Explosive activity at the ocean entry on 26 September was possibly caused by a small bench collapse.
The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW and W. Small amounts of ash were retrieved from collection bins placed near the plume. Weak incandescence from the vent, about 200 m below the Halema'uma'u crater floor, was visible at night. Rushing gas and rockfall sounds were occasionally heard in the vicinity of the vent. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 400, 700, and 665 tonnes per day were measured on 23, 24, and 28 September, respectively. The 2003-2007 average rate was 140 tonnes per day. On 26 September, a series of rockfalls accompanied an apparent collapse of the vent floor, causing the lava level to drop and the plume to turn "dusty brown" for several minutes. On 28 September, a spattering lava pond was seen inside the vent.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| New Britain (Papua New Guinea)
| 5.525°S, 148.42°E
| Elevation 1330 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 29 September an ash plume from Langila rose to altitudes of 2.4-4.3 km (8,000-14,000 ft) a.s.l. and drifted 75-220 km NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| New Britain (Papua New Guinea)
| 4.271°S, 152.203°E
| Elevation 688 m
RVO reported that during 18-24 September gray ash plumes from Rabaul caldera's Tavurvur cone rose 1.5 km above the crater. Ashfall was reported in Rabaul town (3-5 km NW) and surrounding areas. Occasionally, incandescence from the summit crater was seen at night, and incandescent lava fragments were ejected from the crater. Rumbling and roaring noises were reported, although less frequently than during 11-17 September. Based on analyses of satellite imagery, the Darwin VAAC reported that on 29 September an ash plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 75 km NW.
Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash Advisory Centre (VAAC)
| United States
| 60.485°N, 152.742°W
| Elevation 3108 m
On 29 September, AVO reported that seismic activity from Redoubt, along with volcanic gas output, ground deformation, lava dome temperatures, and outward signs of lava dome instability, have been declining during the previous several months. The Volcanic Alert Level was lowered to Normal and the Aviation Color Code was lowered to Green.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| Costa Rica
| 10.025°N, 83.767°W
| Elevation 3340 m
On 25 September, scientists from OVSICORI-UNA reported results from three field trips to Turrialba to inspect new fissures and to assess the impact of gases on surrounding areas. Winds carrying toxic gases 10 km SW, to the S side of Irazú volcano, caused trees to exhibit mild burns to a greater degree than effects from the previous year. Vegetation within a 4-km-radius on the W, NW, and E flanks was also burned more severely that previously noted. Several elongated fissures in the rim S of the W crater were documented, as well as 1 km down slope NW of the crater. One E-W-trending crack that was first seen several months before had opened up as much as 12 cm, and emitted gas and vapor at 90 degrees Celsius. On the NW lower flanks, at least three radial fissures emitted high gas-and-vapor plumes. Some fissures near the summit were 5-10 cm wide. The last of the remaining settlers in the affected areas had moved away due to the intensification and impact of the gases.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Criteria & Disclaimers
The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:
- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.
Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.
It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.
1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.
2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.
3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.
4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.
5. USGS Disclaimer Statement for this Website:
Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.
Some of the documents on this server may contain live references (or pointers) to information created and maintained by other organizations. Please note that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.
For site security purposes and to ensure that this service remains available to all users, this government computer system employs software programs to monitor network traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Unauthorized attempts to upload information or change information on this website are strictly prohibited and may be punishable under the Computer Fraud and Abuse Act of 1986 and the National Information Infrastructure Protection Act. Information may also be used for authorized law enforcement investigations. (Last modified September 21, 1999.)
U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA