New activity/unrest was observed at 5 volcanoes from November 5 - 11, 2014. Ongoing activity was reported for 11 volcanoes.
New activity/unrest: Cerro Negro de Mayasquer, Colombia-Ecuador | Kilauea, Hawaiian Islands (USA) | Popocatepetl, Mexico | Turrialba, Costa Rica | Zhupanovsky, Eastern Kamchatka (Russia)
Ongoing activity: Aira, Kyushu (Japan) | Ambrym, Vanuatu | Bagana, Bougainville (Papua New Guinea) | Bardarbunga, Iceland | Fuego, Guatemala | Mayon, Luzon (Philippines) | Ontakesan, Honshu (Japan) | Reventador, Ecuador | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Sinabung, Indonesia
Cerro Negro de Mayasquer, Colombia-Ecuador
0.828°N, 77.964°W, Elevation 4445 m
On 4 November Servicio Geológico Colombiano's Observatorio Vulcanológico and Sismológico de Pasto (SGC-OVSP) reported that seismic activity at Cerro Negro de Mayasquer and Chiles volcanoes remained elevated. Since 29 September 2014 about 132,000 earthquakes had been detected, with 3,200 of those events occurring on 4 November. During the previous week hypocenters were located 0.3-6.3 km S and SW of Chiles, at depths of 3-9 km below the summit. Local magnitudes were between 0.7 and 4.6. The Alert Level remained at Orange (level 3 of 4).
Geologic summary: Cerro Negro de Mayasquer, astride the Colombia-Ecuador border, is a stratovolcano with a caldera open to the west. Andesitic and dacitic lava flows are of possible Holocene age (Hall 1992, pers. comm.). Solfataras are found on the shore of a small crater lake. An historical eruption reported in 1936 may have been from Reventador (Catalog of Active Volcanoes of the World). The higher, glacier-covered summit of the Pleistocene Chiles stratovolcano lies only 3 km SE. Chiles last erupted about 160,000 years ago, but has hot springs and an active hydrothermal system at its eastern flank.
Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Elevation 1222 m
During 5-11 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. Breakout lava flows behind the stalled leading edge continued to advance. On 10 November the closest active lava to Pahoa Village Road was about 450 m upslope of the road, on the N margin of the flow field. Multiple breakouts were active around Apa’a Street and Cemetery Road. Lava advanced to within 20 m of the transfer station fence and through residential property across the street; at 1155 an unoccupied home on that lot was ignited by advancing lava.
The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the ventcontinued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.
Geologic summary: Kilauea volcano, which overlaps the east flank of the massive Mauna Loa shield volcano, has been Hawaii's most active volcano during historical time. Eruptions of Kilauea are prominent in Polynesian legends; written documentation extending back to only 1820 records frequent summit and flank lava flow eruptions that were interspersed with periods of long-term lava lake activity that lasted until 1924 at Halemaumau crater, within the summit caldera. The 3 x 5 km caldera was formed in several stages about 1500 years ago and during the 18th century; eruptions have also originated from the lengthy East and SW rift zones, which extend to the sea on both sides of the volcano. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 sq km, destroying nearly 200 houses and adding new coastline to the island.
19.023°N, 98.622°W, Elevation 5426 m
CENAPRED reported that a small series of explosions at Popocatépetl, starting at 2003 on 4 November and ending at 0130 on 5 November, produced a continuous plume of gas, steam, and small amounts of ash that rose 1 km and drifted N. The seismic network detected 191 explosions during the period. Incandescent material was periodically ejected onto the N and E flanks, as far as 800 m. Ashfall was reported in Paso de Cortes.
On 6 November a small rockslide on the SW flank was recorded by a webcam and the seismic network. Scientists aboard an overflight observed dome 53, emplaced during 4-5 November; it was an estimated 250 m in diameter and 30 m thick. During 7-11 November seismicity indicated continuing emissions of water vapor, gas, and occasional small amounts of ash. Incandescence from the crater was observed most nights. Explosions were detected during 10-11 November. The first explosion ejected incandescent tephra and generated an ash plume that rose 1.2 km and drifted SE. Others generated plumes that rose as high as 1.2 km and drifted SE and E. The Alert Level remained at to Yellow, Phase Two.
Geologic summary: Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5426 m 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major plinian eruptions, the most recent of which took place about 800 CE, have occurred from Popocatépetl since the mid Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since precolumbian time.
Turrialba, Costa Rica
10.025°N, 83.767°W, Elevation 3340 m
On 7 November OVSICORI-UNA reported that seismic activity at Turrialba had decreased overall during the previous few days. A seismic signal indicating a strong emission started at 2320 on 6 November and lasted about 50 minutes.
Geologic summary: Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.
Zhupanovsky, Eastern Kamchatka (Russia)
53.589°N, 159.15°E, Elevation 2899 m
KVERT reported that a strong explosive eruption at Zhupanovsky occurred at 0955 on 8 November, generating an ash plume that rose to an altitude of 10 km (32,800 ft) a.s.l. and drifted 26 km SSW. The Aviation Color Code was raised to Orange. On 9 November ash plumes detected in satellite images rose to altitudes of 3-4 km (9,800-13,100 ft) a.s.l. and drifted 190-250 km SE.
Geologic summary: The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated volcanic complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene, the fourth is Holocene in age and was the source of all of Zhupanovsky's historical eruptions. An early Holocene stage of frequent moderate and weak eruptions from 7000 to 5000 years before present (BP) was succeeded by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption took place about 800-900 years BP. Historical eruptions have consisted of relatively minor explosions from the third cone.
Aira, Kyushu (Japan)
31.593°N, 130.657°E, Elevation 1117 m
JMA reported that nine explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m during 4-7 November. An explosive eruption on 7 November generated an ash plume that rose 3.5 km. An eruption later that day from Minami-Dake Crater produced a plume that rose 1.4 km. The Alert Level remained at 3 (on a scale of 1-5). The Tokyo VAAC reported that during 5-8 November plumes rose to altitudes of 2.1-4.6 km (7,000-15,000 ft) a.s.l.and drifted NW, W, E, and SE.
Geologic summary: The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.
16.25°S, 168.12°E, Elevation 1334 m
On 10 November the Vanuatu Geohazards Observatory reported that activity at Ambrym remained elevated. The Alert Level remained at 2 (on a scale of 0-4).
Geologic summary: Ambrym, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides arc. A thick, almost exclusively pyroclastic sequence, initially dacitic, then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major plinian eruption with dacitic pyroclastic flows about 1900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the caldera floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations.
Bagana, Bougainville (Papua New Guinea)
6.137°S, 155.196°E, Elevation 1855 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 9 November an ash plume from Bagana drifted 65 km S.
Geologic summary: 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.
64.63°N, 17.53°W, Elevation 2009 m
During 5-11 November, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga’s Holuhraun eruptive fissure. Subsidence of the Bárdarbunga Caldera continued, and seismicity remained strong. The lava field was 60 square kilometers on 9 November. Local air pollution from gas emissions persisted.
Geologic summary: The large central volcano of Bárdarbunga lies beneath the NW part of the Vatnajökull icecap, NW of Grímsvötn volcano, and contains a subglacial 700-m-deep caldera. Related fissure systems include the Veidivötn and Trollagigar fissures, which extend about 100 km SW to near Torfajökull volcano and 50 km NE to near Askja volcano, respectively. Voluminous fissure eruptions, including one at Thjorsarhraun, which produced the largest known Holocene lava flow on Earth with a volume of more than 21 cu km, have occurred throughout the Holocene into historical time from the Veidivötn fissure system. The last major eruption of Veidivötn, in 1477, also produced a large tephra deposit. The subglacial Loki-Fögrufjöll volcanic system located SW of Bárdarbunga volcano is also part of the Bárdarbunga volcanic system and contains two subglacial ridges extending from the largely subglacial Hamarinn central volcano; the Loki ridge trends to the NE and the Fögrufjöll ridge to the SW. Jökulhlaups (glacier-outburst floods) from eruptions at Bárdarbunga potentially affect drainages in all directions.
14.473°N, 90.88°W, Elevation 3763 m
INSIVUMEH reported that during 6-8 November explosions at Fuego produced ash plumes that rose 500-1,050 m above the crater and drifted 10 km WSW. Shock waves from some of the explosions rattled structures within a 12-km radius. The larger explosions generated block avalanches that descended the Santa Teresa (W), Taniluyá (SW), Cenizas (SSW), El Jute (SE), and Las Lajas (SE) ravines. Ashfall was reported in villages on the W and SW flanks.
Geologic summary: Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.
Mayon, Luzon (Philippines)
13.257°N, 123.685°E, Elevation 2462 m
PHIVOLCS reported that during 5-11 November white plumes rose from Mayon's crater and drifted S, SW, WSW, WNW, and NW, sometimes downslope. Weak incandescence from the crater was noted some nights. As many as five volcanic earthquakes were recorded per day. The Alert Level remained at 3 (on a 0-5 scale).
Geologic summary: Beautifully symmetrical Mayon volcano, which rises to 2462 m above the Albay Gulf, is the Philippines' most active volcano. The structurally simple volcano has steep upper slopes averaging 35-40 degrees that are capped by a small summit crater. Historical eruptions at this basaltic-andesitic volcano date back to 1616 and range from strombolian to basaltic plinian, with cyclical activity beginning with basaltic eruptions, followed by longer term andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic flows and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often devastated populated lowland areas. Mayon's most violent eruption, in 1814, killed more than 1200 people and devastated several towns.
Ontakesan, Honshu (Japan)
35.893°N, 137.48°E, Elevation 3067 m
JMA reported that cloud cover often prevented visual observations of Ontakesan during 5-11 November; white plumes rose 200-300 m above the crater rim and drifted NE, E, and SE. The Alert Level remained at 3 (on a scale of 1-5).
Geologic summary: The massive Ontakesan stratovolcano, the second highest volcano in Japan, lies at the southern end of the Northern Japan Alps. It is constructed within a largely buried 4 x 5 km caldera and occupies the southern end of the Norikura volcanic zone, which extends northward to Yakedake volcano. The older volcanic complex consisted of at least four major stratovolcanoes constructed from about 680,000 to about 420,000 years ago, after which Ontakesan was inactive for more than 300,000 years. The broad, elongated summit of the younger edifice is cut by a series of small explosion craters along a NNE-trending line. Several phreatic eruptions post-date the roughly 7300-year-old Akahoya tephra from Kikai caldera. The first historical eruption took place in 1979. A non-eruptive landslide in 1984 produced a debris avalanche and lahar that swept down valleys south and east of the volcano. Ascending this volcano is one of the major objects of religious pilgrimage in central Japan.
0.077°S, 77.656°W, Elevation 3562 m
IG reported moderate volcanic activity including explosions, long-period earthquakes, harmonic tremor, and tremor at Reventador during 5-11 November. On 11 November steam plumes with a minor ash content rose 1 km and drifted NW. Cloudy conditions frequently obscured views of the summit.
Geologic summary: Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic Volcán El Reventador stratovolcano rises to 3562 m above the jungles of the western Amazon basin. A 4-km-wide caldera widely breached to the east was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1300 m above the caldera floor to a height comparable to the caldera rim. It has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera. The largest historical eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents.
Sheveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E, Elevation 3283 m
KVERT reported that during 31 October-7 November lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot avalanches, andfumarolic activity. Satellite images detected a thermal anomaly over the dome during 1-3 November; cloud cover prevented views of the volcano on the other days. The Aviation Color Code remained at Orange.
Geologic summary: The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1300 cu km volcano is one of Kamchatka's largest and most active volcanic structures. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.
Shishaldin, Fox Islands (USA)
54.756°N, 163.97°W, Elevation 2857 m
AVO reported that seismicity at Shishaldin remained elevated during 5-11 November. Satellite and webcam views showed nothing unusual; temperatures at the summit were elevated on 5 November. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Geologic summary: The beautifully symmetrical volcano of Shishaldin is the highest and one of the most active volcanoes of the Aleutian Islands. The 2857-m-high, glacier-covered volcano is the westernmost of three large stratovolcanoes along an E-W line in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." A steady steam plume rises from its small summit crater. Constructed atop an older glacially dissected volcano, it is Holocene in age and largely basaltic in composition. Remnants of an older ancestral volcano are exposed on the west and NE sides at 1500-1800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is blanketed by massive aa lava flows. Frequent explosive activity, primarily consisting of strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century.
3.17°N, 98.392°E, Elevation 2460 m
The Darwin VAAC reported that eruptions from Sinabung were recorded by a webcam during 4-7 and 10-11 November. Based on a report from PVMBG, the VAAC reported that an eruption on 9 November produced an ash plume that rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted over 35 km NW.
Geologic summary: Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks. The migration of summit vents along a N-S line gives the summit crater complex an elongated form. The youngest crater of this conical, 2460-m-high andesitic-to-dacitic volcano is at the southern end of the four overlapping summit craters. An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks of Sinabung in 1912. No confirmed historical eruptions were recorded prior to explosive eruptions during August-September 2010 that produced ash plumes to 5 km above the summit.