New activity/unrest was observed at 6 volcanoes from June 11 - 17, 2014. Ongoing activity was reported for 11 volcanoes.
New activity/unrest: Bezymianny, Central Kamchatka (Russia) | Nishinoshima, Japan | Pavlof, United States | Sangeang Api, Indonesia | Semisopochnoi, United States | Zhupanovsky, Eastern Kamchatka (Russia)
Ongoing activity: Bagana, Bougainville (Papua New Guinea) | Batu Tara, Komba Island (Indonesia) | Dukono, Halmahera (Indonesia) | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaiian Islands (USA) | San Miguel, El Salvador | Santa María, Guatemala | Shishaldin, Fox Islands (USA) | Shiveluch, Central Kamchatka (Russia) | Ubinas, Peru
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 23:00 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail.
Bezymianny, Central Kamchatka (Russia)
55.978°N, 160.587°E, Summit elev. 2882 m
KVERT reported that seismicity at Bezymianny increased on 17 June, when about 12 shallow events were recorded that were thought to be caused by extrusion of material at the top of the lava dome. A thermal anomaly was also identified using satellite data. The Aviation Color Code was raised from Yellow to Orange.
Geologic summary: Prior to its noted 1955-56 eruption, Bezymianny volcano had been considered extinct. The modern Bezymianny, much smaller in size than its massive neighbors Kamen and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene lava-dome complex and an ancestral volcano that was built between about 11,000-7000 years ago. Three periods of intensified activity have occurred during the past 3000 years. The latest period, which was preceded by a 1000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of Mount St. Helens in 1980, produced a large horseshoe-shaped crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater.
27.247°N, 140.874°E, Summit elev. 25 m
Photographs and video taken from a Japanese Coast Guard helicopter on 11 and 13 June revealed continuing eruptive activity at Nishinoshima. Steaming along the shoreline indicated at least two locations with active, or recently active, lava ocean entries, possibly tube-fed since no surface incandescence was visible. Night video clearly showed an active lava flow and ocean entry being supplied from lava fountaining out of a cinder cone. A significant steam plume was rising from the center of the lava shield from hot tephra deposits over a broad area rather than a crater. However, pulsating tephra ejections and distinctly brown ashplumes were rising from two smaller craters. An incandescent lava lake was visible in one of the small craters on both days.
Similar Coast Guard photos taken on 21 May showed a large ash-bearing plume and Strombolian activity from a larger cinder cone in the center of the island. Minor steaming from two central cinder cones was photographed on 15 April, and incandescent lava could be seen in the crater of one.
Geologic summary: The small island of Nishinoshima was recently enlarged when it was joined to several new islands that formed during an eruption in 1973-74. Water discoloration has been observed on several occasions since. The 700-m-wide island is the summit of a massive submarine volcano that has prominent satellitic peaks to the S, W, and NE. The summit of the southern cone rises to within 214 m of the sea surface 9 km SSE.
Pavlof, United States
55.42°N, 161.887°W, Summit elev. 2519 m
AVO reported that the eruption at Pavlof continued during 11-16 June. Seismic activity was steady and characterized by intermittent events. Weakly elevated surface temperatures were occasionally observed in mostly cloudy satellite images.The Aviation Color Code remained at Orange and the Volcano Alert Levelremained at Watch.
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 of Pavlof took place in 1911, at the end of a 5-year-long eruptive episode. During this eruption a fissure opened on the northern flank of the volcano, ejecting large blocks and issuing lava flows.
Sangeang Api, Indonesia
8.2°S, 119.07°E, Summit elev. 1949 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 14 June an ash plume from Sangeang Api rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 55 km NW.
Geologic summary: Sangeang Api volcano, one of the most active in the Lesser Sunda Islands, forms a small 13-km-wide island off the NE coast of Sumbawa Island. Two large trachybasaltic-to-
Semisopochnoi, United States
51.93°N, 179.58°E, Summit elev. 1221 m
AVO reported that an earthquake swarm at Semisopochnoi started at 1000 on 9 June and escalated at 1200 on 12 June. The continuation of the anomalous activity prompted AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory on 13 June. The earthquake swarm was continuing as of 17 June. Five of the six seismic stations on the volcano were operational.
Geologic summary: Semisopochnoi, the largest subaerial volcano of the western Aleutians, is 20 km wide at sea level and contains an 8-km-wide caldera. It formed as a result of collapse of a low-angle, dominantly basaltic volcano following the eruption of a large volume of dacitic pumice. The high point of the island is 1221-m-high Anvil Peak, a double-peaked late-Pleistocene cone that forms much of the island's northern part. The three-peaked 774-m-high Mount Cerberus volcano was constructed during the Holocene within the caldera. Each of the peaks contains a summit crater; lava flows on the northern flank of Cerberus appear younger than those on the southern side. Other post-caldera volcanoes include the symmetrical 855-m-high Sugarloaf Peak SSE of the caldera and Lakeshore Cone, a small cinder cone at the edge of Fenner Lake in the NE part of the caldera. Most documented historical eruptions have originated from Cerberus, although Coats (1950) considered that both Sugarloaf and Lakeshore Cone within the caldera could have been active during historical time.
Zhupanovsky, Eastern Kamchatka (Russia)
53.59°N, 159.147°E, Summit elev. 2958 m
KVERT reported that satellite images over Zhupanovsky detected gas-and-steam plumes drifting 100 km E on 9 and 11 June. Snow in the region was covered by ash. The Aviation Color Code remained at Yellow.
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 of Zhupanovsky took place about 800-900 years BP. Historical eruptions have consisted of relatively minor explosions from the third cone.
Bagana, Bougainville (Papua New Guinea)
6.14°S, 155.195°E, Summit elev. 1750 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 11-12 June ash plumes from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 25-40 km SW and W.
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, roughly 1750-m-high 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 frequent and 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 data, the Darwin VAAC reported an ash plume from Batu Tara on 15 June rising to an altitude of 2.1 km (7,000 ft) a.s.l. and drifting 55 km SW. During 16 June the plume was slightly lower, at 1.5 km (5,000 ft) a.s.l., extending 37 km NW.
Geologic summary: The small isolated island of Batu Tara in the Flores Sea about 50 km north of Lembata (fomerly 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.
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 on 11 June an ash plume from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted over 35 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 north-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, 90.88°W, Summit elev. 3763 m
INSIVUMEH reported that explosive activity from Fuego continued in mid-June. Explosions during 12-14 June sent ash plumes as high as 4,600 m (15,000 ft) a.s.l. that drifted 9-11 km S and W. Small avalanches also continued.
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 volcano dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta volcano 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 volcano, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. 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.
Karymsky, Eastern Kamchatka (Russia)
54.05°N, 159.45°E, Summit elev. 1536 m
KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 6-13 June. Satellite images detected a thermal anomaly on 11 June; clouds obscured the volcano on the other days. 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 during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, which is located immediately south of Karymsky volcano. The caldera enclosing Karymsky volcano formed about 7600-7700 radiocarbon years ago; construction of the Karymsky stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-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.
Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Summit elev. 1222 m
During 11-17 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.
At Pu'u 'O'o Crater, glow emanated from spatter cones on the N, SE, and S portions of the crater floor, and from a small lava lake in the NE spatter cone. On 22 May geologists mapped the farthest point of activity from the Kahauale’a 2 lava flow, 8.4 km NE of Pu’u 'O'o, and on 6 June they mapped four small breakouts as far as 6.5 km from Pu’u 'O'o. Smoke plumes rising from forested areas suggested advancing lava from a new 12 June breakout at the N base of the Pu’u 'O'o cone. Overall, however, this slow-moving flow has appeared to be weakening over the past few months.
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.
San Miguel, El Salvador
13.434°N, 88.269°W, Summit elev. 2130 m
According to SNET, the Ministerio de Medio Ambiente y Recursos Naturales (MARN) reported that seismicity at San Miguel increased significantly during 11-12 June, and remained very high through 17 June. Webcam images on 17 June showed a small steam plume rising from the summit crater.
Geologic summary: The symmetrical cone of San Miguel volcano, one of the most active in El Salvador, rises from near sea level to form one of the country's most prominent landmarks. The unvegetated summit of the 2130-m-high volcano rises above slopes draped with coffee plantations. A broad, deep crater complex that has been frequently modified by historical eruptions (recorded since the early 16th century) caps the truncated summit of the towering volcano, which is also known locally as Chaparrastique. Radial fissures on the flanks of the basaltic-andesitic volcano have fed a series of historical lava flows, including several erupted during the 17th-19th centuries that reached beyond the base of the volcano on the north, NE, and SE sides. The SE-flank lava flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. The location of flank vents has migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater.
Santa María, Guatemala
14.756°N, 91.552°W, Summit elev. 3772 m
Eruptions continued at Santa María's Santiaguito lava-dome complex during the week of 11-17 June. INSIVUMEH reported small avalanches to the W and ashplumes drifting SW at altitudes of 2,800-3,200 m (9,000-10,500 ft) a.s.l.
Geologic summary: Symmetrical, forest-covered Santa María volcano is one of the most prominent of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The 3772-m-high stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1.5-km-wide crater. The oval-shaped crater extends from just below the summit of Volcán Santa María to the lower flank and was formed during a catastrophic eruption in 1902. The renowned plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four westward-younging vents, the most recent of which is Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.
Shishaldin, Fox Islands (USA)
54.756°N, 163.97°W, Summit elev. 2857 m
AVO reported that, although cloudy conditions frequently obscured webcam and satellite views of Shishaldin during 11-16 June, seismicity indicated that the low-level eruption continued. Strongly elevated surface temperatures at the summit were detected in satellite data on the morning of 16 June. 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, Shishaldin 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. Shishaldin contains 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.
Shiveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E, Summit elev. 3283 m
KVERT reported that during 6-13 June lava-dome extrusion onto Shiveluch’s SE flank was accompanied by ash explosions, incandescence, hot avalanches, andfumarolic activity. Satellite images detected a thermal anomaly and an ash plume drifting 70 km SW during 7-8 and 12 June. Ashfall in Klyuchi (50 km SW) was reported on 11 June. 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. The 1300 cu km Shiveluch 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 of Shiveluch 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.
16.355°S, 70.903°W, Summit elev. 5672 m
In a 12 June press release, IGP's Observatorio Volcanologico de Arequipa (IGP-OVA) reported that activity at Ubinas had decreased since April, however periods of intense tremor mainly associated with ash emissions continued to be detected. Ashfall affected areas around the volcano, especially within 6 km E and SSW. An IGP update on 17 June noted a small explosion at 1335 that day that sent ash 1,800 m above the crater, to an altitude of about 7,400 m (24,500 ft) a.s.l.
Geologic summary: A small, 1.4-km-wide caldera cuts the top of Ubinas, Peru's most active volcano, giving it a truncated appearance. Ubinas 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 volcano was followed by construction of Ubinas II volcano 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 of Ubinas about 3700 years ago extend 10 km from the volcano. Widespread plinian pumice-fall deposits from Ubinas include one of Holocene age about 1000 years ago. Holocene lava flows are visible on the volcano's flanks, but historical activity, documented since the 16th century, has consisted of intermittent minor-to-moderate explosive eruptions.