Activity for the week of 16 May-22 May 2012
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
| 14.473°N, 90.88°W
| Elevation 3763 m
On 19 May seismicity at Fuego increased and explosions were heard at 5-10 minute intervals. A 600-m-long lava flow descended the W flank, and a 1-km-long and 20-m-wide lava flow descended the E flank, reaching the base of the volcano. Explosions ejected incandescent tephra 400 m above the crater, and produced ash plumes that rose 5 km above the crater and drifted 30 km S and SW. Coordinadora Nacional para la Reducción de Desastres (CONRED) raised the Alert Level to Orange (the second highest level on a 4-color scale). Pyroclastic flows also descended the flanks, prompting authorities to restrict passage on part of a highway. Ash plumes from the pyroclastic flows rose 3 km above the crater. Ashfall was reported in Morelia (7 km SW), Panimaché I and II (9 km SW), Sangre de Cristo (8 km WSW), and Yepocapa (8 km WNW). Thirteen people from El Porvenir in Alotenango (8 km ENE) evacuated to local shelters. Visual observations and seismicity indicated that activity decreased later that day.
On 20 May a few explosions generated ash plumes that rose 500 m above the crater and drifted 8 km SW. The next day cloud cover prevented observations; however explosions, rumbling, and degassing sounds were reported. On 22 May explosions generated ash plumes that rose as high as 1 km and drifted 10 km S and SE. Rumbling was heard and shock waves were detected. The lava flows were inactive and only incandescence from block avalanches was observed.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Coordinadora Nacional para la Reducción de Desastres (CONRED)
| 0.38°S, 100.474°E
| Elevation 2885 m
According to a news article, an approximately 10-minute-long eruption from Marapi produced an ash plume that rose 600 m on 18 May. The article noted that the Alert Level remained at 2 (on a scale of 1-4).
Source: MI News 26
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on information from JMA, the Tokyo VAAC reported that during 16-20 and 22 May explosions from Sakura-jima produced plumes that rose to altitudes of 1.8-3.7 km (6,000-12,000 ft) a.s.l. and drifted multiple directions. Pilots observed ash plumes during 16-17 May that rose to altitudes of 2.7-4 km (9,000-13,000 ft) a.s.l. and drifted E and SE. Explosions were detected during 21-22 May.
JMA reported that during 18-21 May explosive eruptions from Showa Crater occurred multiple times and ejected tephra as far as 1.8 km from the crater. Incandescence from the crater was observed at night. Very small eruptions from Minami-dake Crater occurred on 18 and 19 May, and a small pyroclastic flow traveled 300 m down the Showa crater flanks on 21 May.
Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Japan Meteorological Agency (JMA)
| Komba Island (Indonesia)
| 7.791°S, 123.585°E
| Elevation 633 m
Based on analyses of satellite imagery, the Darwin VAAC reported that during 18 and 20-21 May ash plumes from Batu Tara rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted 27-55 km N and NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Chuginadak Island (USA)
| 52.825°N, 169.944°W
| Elevation 1730 m
AVO reported that during 16-22 May satellite observations of Cleveland's summit crater revealed nothing unusual; no ash emissions or other signs of unrest were detected or reported. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 18 May an ash plume from Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 55 km E.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
KVERT reported that moderate seismic activity from Karymsky continued to be detected during 11-18 May, and indicated that possible ash plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 10 and 14 May. Satellite imagery showed a thermal anomaly on the volcano during 10-13 and 16 May. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 16-22 May HVO reported that the circulating and spattering lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, and spilled over the deep inner ledge on multiple occasions. On 15 May laser measurements indicated that the lava-lake surface was about 65 m below the Halema'uma'u Crater floor, among the highest levels measured; the lake rose five more meters during 18-19 May. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter from the margins of the lava lake, onto nearby areas. A lava pond in a small pit on the E edge of Pu'u 'O'o crater floor remained active with spattering. On 19 May a small collapse of the N rim of the pit slightly enlarged the pit and lava pond within. A small lava flow erupted from a vent on the S part of the floor. Lava flows were active on the pali and the coastal plain, and were about 750 m from the sea.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| 19.023°N, 98.622°W
| Elevation 5393 m
CENAPRED reported that, although cloud cover often prevented observations of Popocatépetl during 16-22 May, multiple gas-and-ash plumes were observed daily rising as high as 1.5 km above crater. Plumes drifted NW, NE, SE, and SW. Incandescent fragments ejected from the crater landed on the flanks as far as 800 m away. Seismicity remained high. The Alert Level remained at Yellow Phase Three.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
| 14.757°N, 91.552°W
| Elevation 3745 m
INSIVUMEH reported that on 21 May a lahar traveled down Santa María's Rio Nima II drainage, carrying tree branches and 40-cm-wide lava blocks. On 22 May explosions produced ash plumes that rose 900 m above Caliente dome and drifted 10 km SE. Ashfall was reported in San Felipe (15 km SSW), El Nuevo Palmar (12 km SSW), and areas on the E flank.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that explosive activity at Shiveluch continued during 11-18 May. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the active crater, and was accompanied by fumarolic activity and lava-dome incandescence. Satellite imagery during 10-12 and 15-16 May showed a thermal anomaly on the lava dome. On 12 May observers reported that ash plumes rose to an altitude of 8 km (26,200 ft) a.s.l. and satellite imagery showed an ash plume drifting more than 800 km E.
Based on information from KVERT and analyses of satellite images, the Tokyo VAAC reported that on 20 May an ash plume rose to an altitude of 9.1 km (30,000 ft) a.s.l. and drifted SW. Images the next day showed that the ash had dissipated.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| 1.467°S, 78.442°W
| Elevation 5023 m
IG reported that during 16-22 May visual observations of Tungurahua were often limited due to cloud cover. On 16 May a steam-and-gas plume drifted W and lahars descended the W flank. On 18 May ashfall was reported in Manzano (8 km SW), Choglontus (SW), Chontapamba (W), Yuibug, Puela (8 km SW), and high in the Mapayacu drainage (SW). Roaring was heard on 22 May, and slight ashfall was reported in Manzano.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
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