Activity for the week of 11 April-17 April 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
| Chuginadak Island (USA)
| 52.825°N, 169.944°W
| Elevation 1730 m
AVO reported that elevated surface temperatures were observed over Cleveland in satellite imagery during 11-12 April. Two explosions were detected on 13 April by distant seismic stations and infrasound arrays. Neither of these explosions produced an ash cloud that could be detected in satellite images. There was no evidence of explosive activity or eruption of lava in the summit crater during 14-17 April. No seismic information was available because Cleveland does not have a real-time seismic network.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| 19.023°N, 98.622°W
| Elevation 5393 m
CENAPRED reported that during 11-15 April steam-and-gas emissions from Popocatépetl occasionally contained ash; emissions contained a substantial amount of ash on 12 April. Seismicity increased on 13 April and at 2220 an explosion ejected incandescent blocks that landed on the NE flank as far as 500 m away from the crater rim. A larger explosion at 2236 ejected incandescent blocks that landed even further away on all flanks; an ash plume rose 2 km above the crater and drifted ENE. Ashfall was reported in San Pedro Benito Juarez (10-12 km SE), where the explosion was also heard. On 14 April gas-and-steam plumes that contained small amounts of ash drifted SW. Multiple emissions occurred with increased incandescence from the crater. Ejected incandescent blocks landed back in the crater or on the flanks 500-800 m from the rim. Gas-and-ash plumes drifted ESE. Ashfall was reported in multiple towns, including Puebla (50 km to the E), San Pedro Benito Juarez, Santiago Xalitzintla (15 km NE), Tianguismanalco, and Atlixco (25 km SE).
On 15 April an ash plume rose 1.5 km above the crater and drifted E. Gas-and-ash emissions rose 1 km above the crater on 16 April and were accompanied by ejected incandescent fragments that were deposited on the flanks, especially to the N and NE. Later that day ash plumes rose 2 km above the crater and drifted E. Ashfall was again reported in Puebla. CENAPRED increased the Alert Level at the volcano from Yellow Phase Two to Yellow Phase Three. During 16-17 April incandescence extended 300 m above the crater and gas-and-steam emissions were constant. Gas-and-ash plumes rose from the crater on 17 April.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Rincon de la Vieja
| Costa Rica
| 10.83°N, 85.324°W
| Elevation 1916 m
OVSICORI-UNA reported that a small phreatic eruption occurred within and around the hot acidic lake of Rincon de la Vieja at 1400 on 14 April. Observers from nearby communities N of the volcano reported some sediment deposition along the outer N flanks of the main active crater and a white steam plume rising to a considerable height above the crater.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
On 6, 8, and 10 April a visitor to Sakura-jima observed and photographed several Vulcanian explosions from Showa crater and noted that the crater was approximately 20% wider from N to S that in the beginning of 2010.
Source: Richard Roscoe, Photo Volcanica
| Sicily (Italy)
| 37.748°N, 14.999°E
| Elevation 3295 m
Sezione di Catania - Osservatorio Etneo reported that the twenty-fourth paroxysmal eruptive episode since January 2011 took place at New SE Crater (New SEC) of Etna during the morning of 12 April following about 10 days of quiescence. The episode was characterized by lava fountains, emissions of ash and lapilli, and lava flows that descended the Valle del Bove and explosively interacted with snow cover.
Source: Sezione di Catania - Osservatorio Etneo (INGV)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
KVERT reported that during 7-13 April moderate seismic activity from Karymsky continued to be detected, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 7 and 9-10 April, and ash deposits 15 km long on the E flank on 11 April. 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 11-17 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter, nearby. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.4 km from the coast. On 11 and 13 April small lava flows issued from a vent on the SE edge of the Pu'u 'O'o crater floor.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Nevado del Ruiz
| 4.892°N, 75.324°W
| Elevation 5279 m
According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that seismicity at Nevado del Ruiz decreased during 11-15 April then slightly increased during 16-17 April. Earthquakes were located below or N of Arenas crater at depths of 1.5-2 km during 11-12 April. Earthquake events at 1146 and 1149 on 15 April were possibly associated with ash emissions which were not verified due to weather conditions. Earthquakes detected on 16 April occurred E of Arenas crater at depths of 1.5-4 km.
Gas-and-steam plumes were observed mainly in satellite imagery, by cameras located near the volcano, and from the city of Manizales (25 km NW). On 12 April a sulfur odor was reported in the towns of Lebanon, Palocabildo, and Fresno (Tolima). Observes in Manila reported a gas-and-steam plume that rose 1.8 km above the crater on 16 April. The Alert Level remained at II (Orange; "eruption likely within days or weeks").
Source: Servicio Geológico Colombiano (SGC)
| Mariana Islands (USA)
| 18.13°N, 145.8°E
| Elevation 570 m
Minor steam-and-gas plumes from Pagan were observed in satellite images during clear periods from 6 to 13 April. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory. According to the Washington VAAC satellite images showed a plume that drifted N. Satellite images and pilot reports indicated no ash in the plume. Emissions to the W had become diffuse.
Sources: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program, Washington Volcanic Ash Advisory Center (VAAC)
| 40.59°S, 72.117°W
| Elevation 2236 m
OVDAS-SERNAGEOMIN reported that, although cloud cover often prevented observations during 11-17 April, satellite and web camera views of the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, showed plumes almost daily that rose no higher than 1 km above the crater. Incandescence from the crater was observed during 10-11 April. The Alert Level remained at Orange.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that explosive activity at Shiveluch continued during 7-13 April. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. Satellite imagery showed a weak thermal anomaly daily on the lava dome, and ash plumes that drifted 210 km SW and SE on 6, 8, and 11 April. Seismic data indicated that ash plumes potentially rose to an altitude of 7.7 km (25,000 ft) a.s.l. during 7-8 and 10-12 April, and to an altitude of 4.5 km (14,800 ft) a.s.l. on the other days. Observers confirmed that an ash plume rose to an altitude of 5 km (16,400 ft) a.s.l. on 8 April. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 1.467°S, 78.442°W
| Elevation 5023 m
IG reported that during 11-15 April visual observations of Tungurahua were occasionally limited due to cloud cover. On 11 April an ash plume rose 5 km above the crater and drifted NE and SE. Ashfall was reported in areas 8 km SW. An explosion on 12 April was followed by ashfall in multiple areas including Ambato (31 km NW), Cusúa (8 km NW), and Bilbao (8 km W). A small ash plume drifted ESE on 13 April and steam plumes drifted SE during 13-14 April. Fumarolic activity in the crater was observed on 15 April.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
| 39.42°S, 71.93°W
| Elevation 2847 m
According to Projecto Observación Visual Volcán Villarrica (POVI), ash emissions rose from Villarrica on 9 April and incandescence emanated from the crater at night.
Source: Proyecto Observación Villarrica Internet (POVI)
News Feeds and Google Placemarks
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A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.
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.
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RSS and CAP Feeds
An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.
At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.
CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management.
Google Earth Placemarks
A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.