New activity/unrest was reported for 6 volcanoes from December 17 - December 23, 2014. Ongoing activity was observed at 7 volcanoes.
New activity/unrest: Asosan, Kyushu (Japan) | Chirinkotan, Kuril Islands (Russia) | Fogo, Cape Verde | Gamalama, Halmahera (Indonesia) | Nevado del Ruiz, Colombia | Popocatepetl, Mexico
Ongoing activity: Bardarbunga, Iceland | Kilauea, Hawaiian Islands (USA) | Mayon, Luzon (Philippines) | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Sinabung, Indonesia | Zhupanovsky, Eastern Kamchatka (Russia)
Asosan, Kyushu (Japan)
32.884°N, 131.104°E | Elevation 1592 m
JMA reported that, based on seismicity and infrasound data, the eruption from Asosan’s Nakadake Crater that began on 25 November continued during 15-22 December. Plumes rose 600-1,000 m above the crater and incandescent material was sometimes ejected onto the crater rim. Sulfur dioxide emissions were 2,000-3,100 tons/day during field observations on 15 and 18 December. The Alert Level remained at 2 (on a scale of 1-5).
Geologic summary: The 24-km-wide Asosan caldera was formed during four major explosive eruptions from 300,000 to 90,000 years ago. These produced voluminous pyroclastic flows that covered much of Kyushu. The last of these, the Aso-4 eruption, produced more than 600 cu km of airfall tephra and pyroclastic-flow deposits. A group of 17 central cones was constructed in the middle of the caldera, one of which, Nakadake, is one of Japan's most active volcanoes. It was the location of Japan's first documented historical eruption in 553 AD. The Nakadake complex has remained active throughout the Holocene. Several other cones have been active during the Holocene, including the Kometsuka scoria cone as recently as about 210 CE. Historical eruptions have largely consisted of basaltic to basaltic-andesite ash emission with periodic strombolian and phreatomagmatic activity. The summit crater of Nakadake is accessible by toll road and cable car, and is one of Kyushu's most popular tourist destinations.
Chirinkotan, Kuril Islands (Russia)
48.98°N, 153.48°E | Elevation 724 m
SVERT reported that a thermal anomaly over Chirinkotan was detected in satellite images on 15 and 21 December. Cloud cover obscured views on the other days during 16-22 December. The Aviation Color Code remained at Yellow.
Geologic summary: The small, mostly unvegetated 3-km-wide island of Chirinkotan occupies the far end of an E-W-trending volcanic chain that extends nearly 50 km west of the central part of the main Kuril Islands arc. Chirinkotan is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. A small 1-km-wide caldera about 300-400 m deep is open to the SE. Lava flows from a cone within the breached crater reached the north shore of the island. Historical eruptions have been recorded at Chirinkotan since the 18th century. Fresh lava flows also descended the SE flank of Chirinkotan during an eruption in the 1880s that was observed by the English fur trader Captain Snow.
Fogo, Cape Verde
14.95°N, 24.35°W | Elevation 2829 m
According to news articles the eruption from Fogo's Pico cone inside the Cha Caldera continued during 17-23 December. On 21 December gas emissions increased and the eruption plume rose 800 m. Lava continued to erupt from the main vents. By 22 December parts of the road in Ilhéu de Losna were overtaken by lava, as well as agricultural fields, a vineyard, and about a dozen homes (one remained by 23 December).
Geologic summary: The island of Fogo consists of a single massive stratovolcano that is the most prominent of the Cape Verde Islands. The roughly circular 25-km-wide island is truncated by a large 9-km-wide caldera that is breached to the east and has a headwall 1 km high. The caldera is located asymmetrically NE of the center of the island and was formed as a result of massive lateral collapse of the ancestral Monte Armarelo edifice. A very youthful steep-sided central cone, Pico, rises more than 1 km above the caldera floor to about 100 m above the caldera rim, forming the 2829 m high point of the island. Pico, which is capped by a 500-m-wide, 150-m-deep summit crater, was apparently in almost continuous activity from the time of Portuguese settlement in 1500 CE until around 1760. Later historical lava flows, some from vents on the caldera floor, reached the eastern coast below the breached caldera.
Gamalama, Halmahera (Indonesia)
0.8°N, 127.33°E | Elevation 1715 m
According to a news article, an eruption at Gamalama on 18 December generated an ash plume that rose 2 km. Nine hikers fell as they ran to safety; four were injured and one was missing. Slow-moving lava at the summit was visible, and ashfall occurred in local villages. The Sultan Baabulah airport, 6 km NE, was closed along with schools and businesses.
Geologic summary: Gamalama (Peak of Ternate) is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera and is one of Indonesia's most active volcanoes. The island of Ternate was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the thorough documentation of Gamalama's historical activity. Three cones, progressively younger to the north, form the summit of Gamalama, which reaches 1715 m. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano. Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63.
Nevado del Ruiz, Colombia
4.895°N, 75.322°W | Elevation 5321 m
Based on a SIGMET notice from the Bogota MWO, the Washington VAAC reported that on 18 and 19 December ash plumes from Nevado del Ruiz rose to altitudes of 7.9 and 9.1 km (26,000 and 30,000 ft) a.s.l., respectively. The plumes drifted SSW. A faint thermal anomaly was detected between cloud cover.
Geologic summary: Nevado del Ruiz is a broad, glacier-covered volcano in central Colombia that covers >200 sq km. Three major edifices, composed of andesitic and dacitic lavas and andesitic pyroclastics, have been constructed since the beginning of the Pleistocene. The modern cone consists of a broad cluster of lava domes built within the summit caldera of an older Ruiz volcano. The 1-km-wide, 240-m-deep Arenas crater occupies the summit. The prominent La Olleta pyroclastic cone is located on the SW flank, and may also have been active in historical time. Steep headwalls of massive landslides cut the flanks of Nevado del Ruiz. Melting of its summit icecap during historical eruptions, which date back to the 16th century, has resulted in devastating lahars, including one in 1985 that was South America's deadliest eruption.
19.023°N, 98.622°W | Elevation 5426 m
CENAPRED reported that the International airport in Puebla temporarily closed on 17 December due to ashfall from a 0446 explosion at Popocatépetl that generated a 2-km-high ash plume. The explosion also ejected incandescent tephra that landed 700 m down the N flank. Three more explosions were detected that day. During 18-23 December seismicity indicated continuing emissions of water vapor, gas, and frequent ash. Incandescence from the crater was visible each night. Three explosions occurred on 18 December; the last one generated an ash plume that rose 2 km and drifted NE. Explosions on 19 December generated ash plumes that rose 500-800 m. Explosions ejected incandescent tephra that landed 100-200 m down from the crater on the NE and N flanks. During an overflight volcanologists observed a lava dome at the bottom of the crater. Two explosions were detected during 22-23 December. The Alert Level remained at 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.
64.63°N, 17.53°W | Elevation 2009 m
During 17-23 December, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga’s Holuhraun eruptive fissure. The lava field covered just over 79.8 square kilometers on 18 December. Data collected during an overflight showed that subsidence of Bárdarbunga Caldera continued with a total amount of 56 m and a volume of 1.7 cubic kilometers since the beginning of the eruption. On 22 December lava was flowing through a closed channel to the E edge of the lava field, about 15 km from the crater. Lava was also flowing N.
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.
Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W | Elevation 1222 m
During 17-23 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system advanced and by 22 December the front was about 1 km above the intersection of Pahoa Village Road and Highway 130, near the Pahoa Marketplace.
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.
Mayon, Luzon (Philippines)
13.257°N, 123.685°E | Elevation 2462 m
On 19 December PHIVOLCS reported that since the last seismic swarm detected at Mayon on 29 November a general decline in the overall activity was noted. Specifically, for the previous three weeks, seismic activity had declined to an average 2-3 mostly volcano-tectonic earthquakes daily, few low-frequency earthquakes were detected, and a few minor rockfall events occurred; deformation data did not indicate magma intrusion; sulfur dioxide emissions had declined on 2 October to below 500 tonnes/day which is the baseline value during periods of quiescence; no lava flows had been observed since 19 October. The Alert Level was lowered to 2 (on a 0-5 scale). PHIVOLCS reminded residents of the 6-km-radius Permanent Danger Zone (PDZ) around the volcano.
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.
Sheveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E | Elevation 3283 m
KVERT reported that during 12-19 December lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot avalanches, and fumarolicactivity. A strong explosion on 17 December generated ash plumes that rose to altitudes of 9-10 km (29,500-32,800 ft) a.s.l. Satellite images detected a thermal anomaly over the dome during 12, 14, and 16-18 December, and ash plumes that drifted 109 km SE during 14-15 December and 35 km ESE on 17 December. 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 continued to be elevated during 17-23 December. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. Occasional steam emissions were recorded by the web camera. 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
PVMBG reported that 53 pyroclastic flows at Sinabung occurred during 8-16 December and traveled as far as 4.5 km S and 1 km SE. Ash plumes rose as high as 5 km and drifted W and SW. Since October a new lava dome had grown from the crater (on the W side of the lava tongue) and was 215 m long. The main lava tongue was about 2,947 m on 15 December. The Alert Level remained at 3 (on a scale of 1-4).
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 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.
Zhupanovsky, Eastern Kamchatka (Russia)
53.589°N, 159.15°E | Elevation 2899 m
KVERT reported that an eruption at Zhupanovsky continued during 12-19 December. Satellite images detected an ash plume drifting 70 km SE on 15 December and intense steam-and-gas emissions on 17 December. The Aviation Color Code remained at Orange.
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.