Active volcanoes in the world: November 19 - 25, 2014

Active volcanoes in the world: November 19 - 25, 2014

New activity/unrest was observed at 4 volcanoes from November 19 - 25, 2014. Ongoing activity was observed at 13 volcanoes. 

New activity/unrest: Fogo, Cape Verde | Pavlof, United States | Popocatepetl, Mexico | Sinarka, Shiashkotan Island (Russia)

Ongoing activity: Aira, Kyushu (Japan) | Asosan, Kyushu (Japan) | Bardarbunga, Iceland | Chirpoi, Kuril Islands (Russia) | Colima, Mexico | Dukono, Halmahera (Indonesia) | Kilauea, Hawaiian Islands (USA) | Mayon, Luzon (Philippines) | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Sinabung, Indonesia | Ubinas, Peru | Zhupanovsky, Eastern Kamchatka (Russia)

New activity/unrest

Fogo, Cape Verde
14.95°N, 24.35°W, Summit elev. 2829 m

According to news articles an eruption from Fogo's Pico cone inside the Cha Caldera began in the morning on 23 November after increased activity detected in the previous weeks and felt earthquakes by residents the night before. The eruption started at a vent on the WSW base of Pico cone, near or at where explosions originated in 1995, and then rose from multiple vents. The activity was characterized by explosions, lava fountains, and ash emissions. About 700 people evacuated from Chã das Caldeiras and the local airport closed. During the afternoon on 24 November workers removed items from the national park headquarters and by the evening lava had overtaken the building. Lava flows had crossed a main road and taken down communication poles. The Toulouse VAAC noted that a cloud observed in satellite images composed mainly of sulfur dioxide drifted over 220 km NW at an altitude of 9.1 km (30,000 ft) a.s.l. Ash in the cloud was detected at lower altitudes. By 25 November the lava flow was 4 km long.

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.

Pavlof, United States
55.417°N, 161.894°W, Summit elev. 2493 m

AVO reported that seismic activity at Pavlof decreased during 21-22 November but continued to remain above background levels. Weakly elevated surface temperatures during 22 and 24-25 November, consistent with the cooling lava flow on the NW flank, were observed in satellite images. The Aviation Color Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory on 25 November; AVO noted that seismicity was at low levels during the previous week, and satellite observations show no evidence for continuing eruptive activity.

Geologic summary: The most active volcano of the Aleutian arc, Pavlof is a 2519-m-high Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and its twin volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, Pavlof has been frequently active in historical time, typically producing Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest historical eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows.

Popocatepetl, Mexico
19.023°N, 98.622°W, Summit elev. 5426 m

CENAPRED reported that during 19-25 November seismicity at Popocatépetl indicated continuing emissions of water vapor and gas. Incandescence from the crater was visible each night. On 21 November a plume with low ash content rose 700 m above the crater and drifted NE. 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.

Sinarka, Shiashkotan Island (Russia)
48.875°N, 154.175°E, Summit elev. 934 m

SVERT reported that satellite images of Sinarka showed steam-and-gas emissions on 19 November. Cloud cover obscured views on the other days during 17-24 November. TheAviation Color Code was raised to Yellow.

Geologic summary: Sinarka volcano, occupying the northern end of Shiashkotan Island in the central Kuriles, has a complex structure. A small, 2-km-wide depression open to the NW has been largely filled and overtopped by an andesitic postglacial central cone that itself contains a lava dome that forms the 934 m high point of the island. Another lava dome, Zheltokamennaya Mountain, lies 1.5 km to the SW along the buried SW rim of the caldera, and a smaller dome lies along the northern caldera rim. Historical eruptions have occurred at Sinarka during the 17th and 18th centuries. The last and largest of these, during 1872-78, was once thought to originate from Kuntomintar volcano at the southern end of the island, but is now attributed to Sinarka volcano (Gorshkov, 1970).

Ongoing activity

Aira, Kyushu (Japan)
31.593°N, 130.657°E, Summit elev. 1117 m

JMA reported that two explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m during 17-21 November. Weak incandescence from the crater was visible during 18-19 November. The Alert Level remained at 3 (on a scale of 1-5). The Tokyo VAAC reported that on 19 November an explosion produced a plume that rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted NE. An eruption on 23 November generated a plume that rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted E.

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.

Asosan, Kyushu (Japan)
32.884°N, 131.104°E, Summit elev. 1592 m

Based on JMA notices, the Tokyo VAAC reported that on 25 November an eruption from Asosan produced a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E.

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.

Bardarbunga, Iceland
64.63°N, 17.53°W, Summit elev. 2009 m

During 18-25 November, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga’s Holuhraun eruptive fissure; FLIR thermal images of the craters on 18 November showed that the most intense area of thermal convection was at the northern part of the eruption site, called Heimasæta. Lava flowed ESE. Subsidence of the Bárdarbunga caldera continued and local air pollution from gas emissions persisted. On 20 November observers characterized the eruption as pulsating explosions in the crater every 10-15 minutes, followed by a gush of lava down the main channel with splashing on either side.

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.

Chirpoi, Kuril Islands (Russia)
46.525°N, 150.875°E, Summit elev. 742 m

SVERT reported that satellite images over Snow, a volcano of Chirpoi, showed a weak thermal anomaly during 17-18 November. Cloud cover obscured views on other days during 19-24 November. The Aviation Color Code remained at Yellow.

Geologic summary: Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. The symmetrical Cherny volcano, which forms the 691 m high point of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No historical eruptions are known from 742-m-high Brat Chirpoev, but its youthful morphology suggests recent strombolian activity.

Colima, Mexico
19.514°N, 103.62°W, Summit elev. 3850 m

Based on a METAR notice and satellite image analyses, the Washington VAAC reported that on 21 November an ash plume from Colima rose to an altitude of 7 km (23,000 ft)a.s.l. and drifted ENE.

Geologic summary: The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.

Dukono, Halmahera (Indonesia)
1.68°N, 127.88°E, Summit elev. 1335 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 19-25 November ash plumes from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l.and drifted 20-150 km NE, WNW, W, and WSW.

Geologic summary: Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the north-flank cone of Gunung Mamuya. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.

Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Summit elev. 1222 m

During 19-25 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A satellite image acquired on 22 November showed that active breakouts were focused in two areas: in the upper part of the flow field about 4 km NE of Pu'u 'O'o, and above the ground crack system near an abandoned geothermal well site on Kilauea’s east rift zone. On 24 November slow-moving pahoehoe flows near the well site had advanced and were 5.7 km SW of the transfer station on Apa'a Street.

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 vent continued 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, Summit elev. 2462 m

PHIVOLCS reported that during 18-25 November white plumes rose from Mayon's crater and drifted WSW, WNW, NE, and SE, often downslope. As many as six volcanic earthquakes and one rockfall event were recorded per day. Sulfur dioxide emissions were below baseline levels. Alert Level remained at 3 (on a 0-5 scale). PHIVOLCS reminded residents of the 6-km-radius Permanent Danger Zone (PDZ) around the volcano and the 7-km Extended Danger Zone (EDZ) on the SE flank.

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, Summit elev. 3283 m

KVERT reported that during 14-21 November lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot avalanches, and fumarolic activity. A strong explosion at 2217 on 16 November generated a 30 x 10 km ash cloud that drifted 590 km SW. Satellite images detected a thermal anomaly over the dome during 18-20 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, Summit elev. 2857 m

AVO reported that intermittent volcanic tremor at Shishaldin continued to be detected during 19-23 November. Elevated crater temperatures were detected in satellite images during periods of clear weather; thermal anomalies were reported during 21-22 November. Seismic activity increased sharply on 24 November, suggesting that the eruption had intensified. Strong thermal anomalies near the summit were detected in satellite images. On 25 November seismicity remained elevated and strongly elevated surface temperatures continued to be detected in satellite images. 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.

Sinabung, Indonesia
3.17°N, 98.392°E, Summit elev. 2460 m

Based on webcam views and weather models, the Darwin VAAC reported that duirng 19-20 November eruptions from Sinabung produced ash plumes that rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted W. Continuous dense white plumes and intermittent pyroclastic flows were also visible. During 22-23 November intermittent pyroclastic flows recorded by the webcam reached the base of the volcano. On 23 November an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted S.

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.

Ubinas, Peru
16.355°S, 70.903°W, Summit elev. 5672 m

According to IGP a small 64-second-long explosion at Ubinas, that started at 0741 on 23 November, produced an ash plume that rose 2.5 km above the crater's base and drifted S and SE. A second explosion occurred at 1004 and generated an ash plume that rose 2.2 km and drifted S. Residents of Ubinas felt a slight rumble at the time of the second explosion.

Geologic summary: A small, 1.4-km-wide caldera cuts the top of Ubinas, Peru's most active volcano, giving it a truncated appearance. It is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front of Perú. The growth and destruction of Ubinas I was followed by construction of Ubinas II beginning in the mid-Pleistocene. The upper slopes of the andesitic-to-rhyolitic Ubinas II stratovolcano are composed primarily of andesitic and trachyandesitic lava flows and steepen to nearly 45 degrees. The steep-walled, 150-m-deep summit caldera contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank about 3700 years ago extend 10 km from the volcano. Widespread plinian pumice-fall deposits include one of Holocene age about 1000 years ago. Holocene lava flows are visible on the flanks, but historical activity, documented since the 16th century, has consisted of intermittent minor-to-moderate explosive eruptions.

Zhupanovsky, Eastern Kamchatka (Russia)
53.589°N, 159.15°E, Summit elev. 2899 m

KVERT reported that a moderate explosive eruption at Zhupanovsky likely continued during 14-21 November. Satellite images showed that the volcano was either quiet or obscured by clouds. 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.

Source: GVP

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