During past seven days 5 volcanoes had new activity, ongoing activity was reported for 10 volcanoes. This report covers active volcanoes in the world from September 11 – September 17, 2013 based on Smithsonian/USGS criteria.
New activity/unrest: | Arenal, Costa Rica | Kliuchevskoi, Central Kamchatka (Russia) | Sakura-jima, Kyushu | Sinabung, Sumatra (Indonesia) | Suwanose-jima, Ryukyu Islands and Kyushu
Ongoing activity: | Bagana, Bougainville | Batu Tara, Komba Island (Indonesia) | Dukono, Halmahera | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kizimen, Eastern Kamchatka (Russia) | Pacaya, Guatemala | Shiveluch, Central Kamchatka (Russia) | Veniaminof, Alaska Peninsula
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.
ARENAL, Costa Rica
10.463°N, 84.703°W; summit elev. 1670 m
OVSICORI-UNA conducted an overflight of Arenal on 14 September to measure gas emissions, and found low concentrations of carbon dioxide, water, and hydrogen sulfide. An infrared camera detected a ring of thermal anomalies along the rim of Crater C.
Geologic summary: Conical Volcan Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1,657-m-high andesitic volcano towers above the eastern shores of Lake Arenal, which has been enlarged by a hydroelectric project. The earliest known eruptions of Arenal took place about 7,000 years ago. Growth of Arenal has been characterized by periodic major explosive eruptions at several-hundred-year intervals and periods of lava effusion that armor the cone. Arenal's most recent eruptive period began with a major explosive eruption in 1968. Continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows has occurred since then from vents at the summit and on the upper western flank.
KLIUCHEVSKOI, Central Kamchatka (Russia)
56.057°N, 160.638°E; summit elev. 4850 m
KVERT reported that moderate seismic activity at Kliuchevskoi was detected during 6-13 September. A video camera recorded incandescence from the summit and the WSW flank at night, and gas-and-steam plumes containing minor amounts of ash. Strombolian activity continued and a lava flow effused onto the W and SW flanks. A large thermal anomaly from the lava dome was detected in satellite images. On 14 September, KVERT stated that lava flows on the NW, W, and SW flanks may soon interact with glaciers, potentially producing tall ash plumes from phreatic explosions. The Aviation Color Code was raised to Orange.
Geologic summary: Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. Kliuchevskoi rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred at Kliuchevskoi during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m elevation. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.
31.585°N, 130.657°E; summit elev. 1117 m
JMA reported that 16 explosions from Sakura-jima's Showa Crater ejected tephra as far as 1,300 m during 9-13 September. Incandescence from the crater was visible some nights. An explosion at 1326 on 12 September generated an ash plume that rose 3.3 km.
Based on information from JMA, the Tokyo VAAC reported that during 11-18 September explosions generated plumes that rose to altitudes of 1.8-4.3 km (6,000-14,000 ft) a.s.l., and drifted in multiple directions on most days. On 12 and 14 September pilots observed ash plumes that rose to an altitude of 4 km (13,000 ft) a.s.l., and drifted SE and W, respectively.
Geologic summary: Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. 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.
SINABUNG, Sumatra (Indonesia)
3.17°N, 98.392°E; summit elev. 2460 m
CVGHM reported that seismicity at Sinabung fluctuated in 2012-2013, including during July-September 2013. During 1-14 September dense white plumes rose 100-150 m above the crater, and at 0255 on 14 September incandescence from the crater was observed. According to news articles an eruption at 0245 on 15 September produced an ash plume and ashfall in Sukameriah (50 km NE), Kutarayat, Kutagugung (16 km SW), and Berastagi (14 km E). About 3,000 people evacuated from areas within a 3-km radius of the volcano, and several flights at Medan's airport (55 km NW) were canceled. CVGHM raised the Alert Level to 3 (on a scale of 1-4).
An eruption at 1203 on 17 September ejected tephra and a dense ash plume that rose higher than the plume from 15 September. According to the Darwin VAAC, a pilot observed an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted 55 km SE. On 18 September a low-level ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.
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, although no confirmed historical eruptions were recorded prior to 2010.
29.635°N, 129.716°E; summit elev. 799 m
According to the Tokyo VAAC, the JMA reported that on 12 September an eruption from Suwanose-jima generated an ash plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted NW.
Geologic summary: The 8-km-long, spindle-shaped island of Suwanose-jima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. Only about 50 persons live on the sparsely populated island. The summit of the volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanose-jima, one of Japan's most frequently active volcanoes, was in a state of intermittent strombolian activity from On-take (Otake), the NE summit crater, that began in 1949 and lasted until 1996, after which periods of inactivity lengthened. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of On-take collapsed forming a large debris avalanche and creating the horseshoe-shaped Sakuchi caldera, which extends to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884.
6.140°S, 155.195°E; summit elev. 1750 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 16-17 September ash plumes from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 35-55 km NW and SW.
Geologic summary: Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia's youngest and most active volcanoes. Bagana is a massive symmetrical lava cone largely constructed by an accumulation of viscous andesitic lava flows. The entire lava cone could have been constructed in about 300 years at its present rate of lava production. Eruptive activity at Bagana is 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.
BATU TARA, Komba Island (Indonesia)
7.792°S, 123.579°E; summit elev. 748 m
Based on analyses of satellite imagery and wind data, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that during 13-17 September ash plumes from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 45-65 km W, NW, and N.
Geologic summary: The small isolated island of Batu Tara in the Flores Sea about 50 km north of Lembata (formerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks of Batu Tara to within 50 m of the 748-m-high summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption from Batu Tara, during 1847-52, produced explosions and a lava flow.
1.68°N, 127.88°E; summit elev. 1335 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 17 September an ash plume from Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 45 km NE.
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 N-flank cone of Gunung Mamuya. Dukono is a complex volcano presenting a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.
14.473°N, 90.880°W; summit elev. 3763 m
INSIVUMEH reported that during 10-11 September explosions from Fuego generated ash plumes that drifted W and NW. Ejected material formed avalanches within the crater. On 10 September lahars that descended the Taniluya (SW) drainage were 15-20 m wide, 1-2 m deep, and carried tree trunks. The lahars blocked roads in Panimache I and II (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW) for two hours. The next day lahars descended the Las Lajas and El Jute drainages (SE); they were 30 m wide, 4 m deep, and carried 2-m-diameter blocks, branches, and tree trunks.
Explosions during 11-12 September produced rumbling sounds and ash plumes that rose 500 m. Incandescent material was ejected 100 m and formed avalanches on the crater rim. A 150-m-long lava flow was active in Ceniza (SSW) drainage. During 12-13 September ash plumes from explosions rose 200-400 m and drifted W and NE. Avalanches from ejected material again formed around the crater. Explosions during 14-15 September generated ash plumes that rose 850 m and drifted 10-12 km W and SW. The explosions produced shock waves that rattled structures in villages within10 km of Fuego. Block avalanches descended Ceniza drainage. During 15-16 September explosions generated ash plumes that rose 550 m and drifted SW, and ejected incandescent material 75-100 m high. Ash fell at the observatory.
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 3,763-m-high Fuego and its twin volcano to the N, Acatenango. Construction of Meseta volcano continued until the late Pleistocene or early Holocene, after which growth of the modern Fuego volcano continued the southward migration of volcanism that began at Acatenango. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua.
KARYMSKY, Eastern Kamchatka (Russia)
54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that moderate seismic activity at Karymsky was detected during 6-13 September. Weak ash explosions likely occurred. Satellite images showed an ash plume drifting 20 km E on 7 September, and a weak thermal anomaly over the volcano during 6 and 10-11 September. The Aviation Color Code remained at Orange.
Geologic summary: Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.
KILAUEA, Hawaii (USA)
19.421°N, 155.287°W; summit elev. 1222 m
During 11-17 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 3.2-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts high on the pali.
Geologic summary: Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 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.
KIZIMEN, Eastern Kamchatka (Russia)
55.130°N, 160.32°E; summit elev. 2376 m
KVERT reported that during 6-13 September moderate seismic activity continued at Kizimen. Video and satellite data showed that lava continued to extrude from the summit, producing incandescence, strong gas-and-steam activity, and hot avalanches on the W and E flanks. A thermal anomaly was detected in satellite images during 8-11 September; cloud cover obscured views on the other days.
On 13 September KVERT noted that activity had been decreasing; both video and satellite data indicated less incandescence from the crater over the past few weeks, and seismicity had decreased significantly at the end of August. Lava possibly continued to extrude from the crater at a low rate. The Aviation Color Code was lowered to Yellow.
Geologic summary: Kizimen is an isolated, conical stratovolcano that is morphologically similar to Mount St. Helens prior to its 1980 eruption. The summit of Kizimen consists of overlapping lava domes, and blocky lava flows descend the flanks of the volcano, which is the westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-m-high Kizimen was formed during four eruptive cycles beginning about 12,000 years ago and lasting 2,000-3,500 years. The largest eruptions took place about 10,000 and 8300-8400 years ago, and three periods of longterm lava-dome growth have occurred. The latest eruptive cycle began about 3,000 years ago with a large explosion and was followed by lava-dome growth lasting intermittently about 1,000 years. An explosive eruption about 1,100 years ago produced a lateral blast and created a 1.0 x 0.7 km wide crater breached to the NE, inside which a small lava dome (the fourth at Kizimen) has grown. A single explosive eruption, during 1927-28, has been recorded in historical time.
14.381°N, 90.601°W; summit elev. 2552 m
INSIVUMEH reported that during 10-11 September explosions at Pacaya generated diffuse ash plumes that rose 150 m and drifted 150 m NW. There were no direct visual observations during 11-12 September, though the seismic network recorded tremor and small explosions. Explosions during 12-13 September ejected material 50-100 m high. White and blue plumes rose 300 m and drifted N. In a special notice on 13 September INSIVUMEH noted that the cone in MacKenney Crater had already grown above the crater rim; incandescence from the cone was visible from many areas around the volcano, including the capital.
Weak-to-moderate explosions generated rumbling during 14-15 September. An increased number of explosions were detected during 15-16 September. Material was ejected above the crater and ash plumes drifted 3 km W and SW. The seismic network recorded tremor and explosions that occurred about every 5 minutes.
Geologic summary: Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex volcano constructed on the southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A cluster of dacitic lava domes occupies the caldera floor. The Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1,100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. During the past several decades, activity at Pacaya has consisted of frequent Strombolian eruptions with intermittent lava flow extrusion on the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions.
SHIVELUCH, Central Kamchatka (Russia)
56.653°N, 161.360°E; summit elev. 3283 m
Based on visual observations and analyses of satellite data, KVERT reported that during 6-13 September a viscous lava flow effused onto the N and NW flanks of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, and fumarolic activity. A thermal anomaly was detected daily in satellite images. At 1128 on 12 September video data showed an ash plume that rose to altitudes of 5-5.5 km (16,400-18,000 ft) a.s.l. and drifted 30 km SE. The Aviation Color Code remained at Orange.
Geologic summary: The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. Intermittent explosive eruptions began in the 1990s from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.
VENIAMINOF, Alaska Peninsula
56.17°N, 159.38°W; summit elev. 2507 m
AVO reported continuous seismic tremor at Veniaminof during 11-17 September, and elevated surface temperatures detected in satellite images that were consistent with lava effusion and fountaining. On 11 September a diffuse steam plume possibly containing ash was recorded by the web cam in Perryville, 32 km SSE. Weak thermal anomalies and decreased levels of tremor during 14-16 September possibly indicated ongoing but diminished lava effusion. No unusual or eruptive activity was observed in web cam images through 17 September. The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange.
Geologic summary: Massive Veniaminof volcano, one of the highest and largest volcanoes on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700 years ago. The caldera rim is up to 520 m high on the N, is deeply notched on the W by Cone Glacier, and is covered by an ice sheet on the S. Post-caldera vents are located along a NW-SE zone bisecting the caldera that extends 55 km from near the Bering Sea coast, across the caldera, and down the Pacific flank. Historical eruptions probably all originated from the westernmost and most prominent of two intra-caldera cones, which reaches an elevation of 2,156 m and rises about 300 m above the surrounding icefield. The other cone is larger, and has a summit crater or caldera that may reach 2.5 km in diameter, but is more subdued and barely rises above the glacier surface.