Smithsonian / USGS Weekly Volcanic Activity Report, 24 December-30 December 2014
Smithsonian / USGS Weekly Volcanic Activity Report
24 December-30 December 2014
New Activity/Unrest: Chirpoi, Kuril Islands (Russia) | Colima, Mexico | Etna, Sicily (Italy) | Gamalama, Halmahera (Indonesia) | Hunga Tonga-Hunga Ha'apai, Tonga Islands | Sabancaya, Peru
Ongoing Activity: Asosan, Kyushu (Japan) | Bagana, Bougainville (Papua New Guinea) | Bardarbunga, Iceland | Kilauea, Hawaiian Islands (USA) | Manam, Papua New Guinea | Popocatepetl, Mexico | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Sinabung, Indonesia | Zhupanovsky, Eastern Kamchatka (Russia)
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.
Note: 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.
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 thermal anomaly on 23 and 25 December. Cloud cover obscured views on other days during 22-29 December. 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
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.
Etna | Sicily (Italy) | 37.734°N, 15.004°E | Summit elev. 3330 m
INGV reported that starting at 1750 on 28 December Etna's New Southeast Crater (NSEC) produced a short but intense eruption characterized by lava fountains, lava flows, and an ash plume that drifted E and caused ash and lapilli fall in Milo, Fornazzo, South Alfio, and Giarre. Inclement weather prevented observations of the summit area so the erupting crater was not identifiable. Two lava flows traveled E and NE, towards the Valle del Bove. Tremor began to decrease at 1930, and indicated that the eruption was over at 2100.
Geologic Summary. Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km horseshoe-shaped caldera open to the east. Two styles of eruptive activity typically occur at Etna. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more of the three prominent summit craters, the Central Crater, NE Crater, and SE Crater (the latter formed in 1978). Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank.
Gamalama | Halmahera (Indonesia) | 0.8°N, 127.33°E | Summit elev. 1715 m
Based on satellite observations, ground reports, and wind data, the Darwin VAAC reported that during 24-25 December ash plumes from Gamalama rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted almost 30 km SW.
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.
Hunga Tonga-Hunga Ha'apai | Tonga Islands | 20.57°S, 175.38°W | Summit elev. 149 m
According to a news article, fisherman had reported an eruption at Hunga Tonga-Hunga Ha'apai on 19 December. A photographer in Tongatapu captured a photo of a steam plume rising from the area on 30 December and noted that steam plumes had been visible since 24 December; dense clouds on the horizon prevented views before then. Terra MODIS imagery from 29 December also showed white plumes and areas of discolored water near the islands.
Geologic Summary. The small islands of Hunga Tonga and Hunga Ha'apai cap a large seamount located about 30 km SSE of Falcon Island. The two linear andesitic islands are about 2 km long and represent the western and northern remnants of the rim of a largely submarine caldera lying east and south of the islands. Hunga Tonga and Hunga Ha'apai reach an elevation of only 149 m and 128 m above sea level, respectively, and display inward-facing sea cliffs with lava and tephra layers dipping gently away from the submarine caldera. A rocky shoal 3.2 km SE of Hunga Ha'apai and 3 km south of Hunga Tonga marks the most prominent historically active vent. Several submarine eruptions have occurred at Hunga Tonga-Hunga Ha'apai since the first historical eruption in 1912.
Sabancaya | Peru | 15.78°S, 71.85°W | Summit elev. 5967 m
Geologic Summary. Sabancaya, located on the saddle between 6288-m-high Ampato and 6025-m-high Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three volcanoes, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. Both Nevado Ampato and Nevado Sabancaya are only slightly affected by glacial erosion and consist of a series of lava domes aligned along a NW-SW trend. The name of 5967-m-high Sabancaya (meaning "tongue of fire" in the Quechua Indian language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of historical eruptions date back to 1750.
Asosan | Kyushu (Japan) | 32.884°N, 131.104°E | Summit elev. 1592 m
JMA reported that, based on seismicity and infrasound data, the eruption from Asosan's Nakadake Crater that began on 25 November continued intermittently during 22-26 December. Plumes rose 1 km above the crater and incandescent material was sometimes ejected onto the crater rim. 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.
Bagana | Bougainville (Papua New Guinea) | 6.137°S, 155.196°E | Summit elev. 1855 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 29 December an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted almost 95 km NE.
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.
Bardarbunga | Iceland | 64.63°N, 17.53°W | Summit elev. 2009 m
During 24-30 December, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga's Holuhraun eruptive fissure. The 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. Seismicity remained strong and local air pollution from gas emissions persisted. The lava field covered 82.8 square kilometers as of 29 December.
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 | Summit elev. 1222 m
During 24-30 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 30 December the front was about 800 m above the intersection of Pahoa Village Road and Highway 130, and 604 m from 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 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.
Manam | Papua New Guinea | 4.08°S, 145.037°E | Summit elev. 1807 m
RVO reported that activity at both Manam's Southern Crater and Main Crater was low during 1-26 December; white vapor emissions rose from both craters. Diffuse gray ash clouds rose at most 200 m from Southern Crater during 21-22 December.
Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys" channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Source: Rabaul Volcano Observatory (RVO)
Popocatepetl | Mexico | 19.023°N, 98.622°W | Summit elev. 5426 m
CENAPRED reported that during 24-30 December seismicity at Popocatépetl indicated continuing emissions of water vapor and gas, which occasionally contained ash during 27-30 December. Cloud cover sometimes prevented views of the crater. Incandescence from the crater was visible some nights. During 24-25 December there were 6-7 explosions detected by the network. An explosion on 26 December generated an ash plume that rose 3.5 km above the crater and drifted NE. Six explosions were detected on 27 December; those at 1258 and 2036 produced ash plumes that rose 0.8-1.5 km and drifted NE. An explosion at 2348 generated a plume with low ash content that rose 0.5 km and drifted S. An explosion on 29 December produced an ash plume that rose 2 km and drifted NE. On 30 December there were 10 explosions that all produced ash plumes that rose 1 km and drifted NE; one of the explosions generated an ash plume that rose 2 km. 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.
Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m
KVERT reported that during 19-26 December lava-dome extrusion onto Sheveluch's N flank was accompanied by incandescence, hot avalanches, and fumarolic activity. A strong explosion on 20 December generated an ash plume that rose to an altitude of 6 km (19,700 ft) a.s.l. Satellite images detected a thermal anomaly over the dome during 19-21 and 23-25 December, and ash plumes drifting 370 km E during 20-21 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 | Summit elev. 2857 m
AVO reported that seismicity at Shishaldin continued to be slightly elevated over background levels during 23-30 December. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera 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
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 | Summit elev. 2899 m
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.