New activity/unrest was observed at 6 volcanoes from June 25 - July 1, 2014. Ongoing activity was reported for 12 volcanoes.
New activity/unrest: Cleveland, Chuginadak Island (USA) | Kusatsu-Shiranesan, Honshu (Japan) | Nyamuragira, DR Congo | Sinabung, Indonesia | Stromboli, Aeolian Islands (Italy) | Zhupanovsky, Eastern Kamchatka (Russia)
Ongoing activity: Aira, Kyushu (Japan) | Bezymianny, Central Kamchatka (Russia) | Dukono, Halmahera (Indonesia) | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaiian Islands (USA) | Pacaya, Guatemala | 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.
Cleveland, Chuginadak Island (USA)
52.825°N, 169.944°W, Summit elev. 1730 m
AVO reported earlier in June that an explosion from Cleveland on the evening of 5 June was detected on the Dillingham acoutstic infrasound array and at seismic stations at Korovin volcano. The brief event was similar to previous explosions at Cleveland, and generated a small detached plume with a weak ash signal observed in satellite imagery. The cloud was at an altitude of about 7.6 km (25,000 ft) a.s.l., had moved about 140 km SW, and rapidly dissipated. The last previous explosion at was 6 March, seen by residents of Nikolski who reported small ash puffs.
Geologic summary: Beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited, dumbbell-shaped Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Cleveland is joined to the rest of Chuginadak Island by a low isthmus. The 1730-m-high Mount Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name for Mount Cleveland, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.
Kusatsu-Shiranesan, Honshu (Japan)
36.618°N, 138.528°E, Summit elev. 2165 m
JMA reported that deformation of Kusatsu-Shiranesan’s crater and the elevated temperatures which began earlier in March, continued during 25-30 June. This activity has been focused in the area immediately of N of Mizugama crater. Some seismicity was also reported, although tremor was absent. The Alert Level remains at 2 (on a scale of 1-5).
Geologic summary: The summit of Kusatsu-Shiranesan volcano, located immediately north of Asama volcano, consists of a series of overlapping pyroclastic cones and three crater lakes. The andesitic-to-dacitic volcano was formed in three eruptive stages beginning in the early to mid Pleistocene. The Pleistocene Oshi pyroclastic flow produced extensive welded tuffs and non-welded pumice that covers much of the east, south and SW flanks. The latest eruptive stage began about 14,000 years ago. All historical eruptions have consisted of phreatic explosions from the acidic crater lakes or their margins. Fumaroles and hot springs that dot the flanks have strongly acidified many rivers draining from the volcano. The crater was the site of active sulfur mining for many years during the 19th and 20th centuries.
Nyamuragira, DR Congo
1.408°S, 29.2°E, Summit elev. 3058 m
On 29 June NASA reported that Nyamuragira vented steam and other volcanic gases and there was a glow from the lava lake. NOAA reported that an Ozone Monitoring Instrument (OMI) satellite detected high SO2 concentrations above Nyamuragira. The University of Hawaii reported that Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data detected thermal anomalies and issued six MODVOLC alerts for the volcano’s N side.
Geologic summary: Africa's most active volcano, Nyamuragira is a massive high-potassium basaltic shield volcano that rises about 25 km north of Lake Kivu, NW of Nyiragongo volcano. Nyamuragira, also known as Nyamulagira, has a volume of 500 cu km, and extensive lava flows from the volcano blanket 1500 sq km of the western branch of the East African Rift. The broad low-angle shield volcano contrasts dramatically with its steep-sided neighbor Nyiragongo. The 3058-m-high summit of Nyamuragira is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Historical eruptions have occurred within the summit caldera, frequently modifying the morphology of the caldera floor, as well as from the numerous fissures and cinder cones on the volcano's flanks. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Historical lava flows extend down the flanks more than 30 km from the summit, reaching as far as Lake Kivu.
3.17°N, 98.392°E, Summit elev. 2460 m
After more than a month of dome growth and lava flows, PVMBG reported that Sinabung erupted explosively again on 29 June. The eruption plume rose to 4 km (13,000 ft) a.s.l. and pyroclastic flows extended 4.5 km SE. Visual observations were impeded by inclement weather. About 14,000 persons remain evacuated since September 2013. The Alert Level remains at 3 (on a scale of 1-4).
Geologic summary: Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks. The migration of summit vents along a N-S line gives the summit crater complex an elongated form. The youngest crater of this conical, 2460-m-high andesitic-to-dacitic volcano is at the southern end of the four overlapping summit craters. An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks of Sinabung 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.
Stromboli, Aeolian Islands (Italy)
38.789°N, 15.213°E, Summit elev. 924 m
INGV reported that during 29-30 June Stromboli erupted a small intracrater lava flow, a lava flow from the crater mouth on the N, and a lava flow on the Sciara del Fuoco on the S. The flows were accompanied by intense spattering and a high frequency of explosions on 29 June.
Geologic summary: Spectacular incandescent nighttime explosions at Stromboli volcano have long attracted visitors to the "Lighthouse of the Mediterranean." Stromboli, the NE-most of the Aeolian Islands, has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout much of historical time. The small, 924-m-high island of Stromboli is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period from about 13,000 to 5000 years ago was followed by formation of the modern Stromboli edifice. The active summit vents are located at the head of the Sciara del Fuoco, a prominent horseshoe-shaped scarp formed about 5000 years ago as a result of the most recent of a series of slope failures that extend to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild strombolian explosions, sometimes accompanied by lava flows, have been recorded at Stromboli for more than a millennium.
Zhupanovsky, Eastern Kamchatka (Russia)
53.59°N, 159.147°E, Summit elev. 2958 m
KVERT reported that during 20-26 June, moderate gas-and-steam activity was observed at Zhupanovsky. Satellite data showed ash plumes drifting 55 km NW from the volcano. During June 27-28 cloud cover prevented views from satellite. The Aviation Color Code is 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.
Aira, Kyushu (Japan)
31.593°N, 130.657°E, Summit elev. 1117 m
JMA reported that during 23-27 June six explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m. During 27-30 June there were four explosions. A significant explosion on 29 June lasted for 17 minutes.The Tokyo VAAC reported that during 25 June-1 July plumes rose to altitudes of 1.2-3.9 km (4,000-13,000 ft) a.s.l. and drifted NW, SE, and E. The Alert Level remained at 3 (on a scale of 1-5).
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.
Bezymianny, Central Kamchatka (Russia)
55.978°N, 160.587°E, Summit elev. 2882 m
KVERT reported that Bezymianny’s activity continued during25-29 June; shallow earthquakes were registered. Video data captured weak gas-and-steam plumes rising from the volcano. Satellite data showed the volcano was frequently obscured by clouds. The Aviation Color Code remained at 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.
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 27-28 June ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 45-75 km NE and E.
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 on 25-29 June weak to moderate explosions generated ash plumes that rose 500-800 m above the crater and drifted 10-12 km W, NW, and SE. Incandescent material that was ejected 100-200 m above the crater landed on the flank and formed avalanches. A lava flow from the crater moving SW towards the Tanilaya drainage generated avalanches into the Ceniza drainage (SSW). On 26 June explosions generated moderate and strong acoustic waves that sounded like a quiet jet engine for a period of 1-2 minutes.
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 dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta 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, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded 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 20-26 June. Satellite images detected no activity or were obscured by clouds. 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 25 June-1 July 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.
During 25-26 June, lava flows from the N and NE spatter cones at Pu'u 'O'o Crater were active and persistent 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 27 June the crater floor slowly subsided and new lava erupted on the N flank. During 27-30 June lava flowed from four locations on the NE flank, advancing to about 1 km NE. Spatter cones collapsed varying amounts. A 28 June satellite image showed that the 27 June lava flows had expanded in area and extended no more than 1.6 km NE of Pu'u 'O'o cone. During 25-27 June there were multiple active breakouts in the interior of the Kahauale`a 2 flow at the north base of Pu'u 'O'o and distant broad smoke plumes, with multiple glowing points visible at night from both near and distant breakouts. Only one stationary glowing spot was seen during 28-30 June on a nearby breakout from the Kahauale`a 2 flow, and little to no smoke from the distal end of that flow, suggesting that the flow was cutoff and dead.
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.
14.381°N, 90.601°W, Summit elev. 2552 m
INSIVUMEH reported that on most days during 25-29 June an ash plume rose 50 m above Pacaya and drifted 400-500 m N and S.
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 basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlán caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the ancestral Pacaya Viejo and Cerro Grande stratovolcanoes and the currently active Mackenney stratovolcano. Collapse of Pacaya Viejo volcano between 600 and 1500 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. A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19th century. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of Mackenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the growing young stratovolcano.
San Miguel, El Salvador
13.434°N, 88.269°W, Summit elev. 2130 m
MARN issued a special report on 27 June and related the unstable system at San Miguel as RSAM values decreased then climbed to fluctuate between 118 and 335. Concentrations of sulfur dioxide (SO2) values measured over the past 24 hours have fluctuated between good and unhealthy.
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
INSIVUMEH reported that during 25-29 June Santa María's Santiaguito lava-dome complex generated ash plumes that rose 200-300 m and drifted 2-3 km SW. A few avalanches were reported moving down the SW flank toward the San Isidro river canyon and from the lava flow E toward the Nima I river. Ashfall was reported in Monte Claro (S).
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 during 25 June – 1 July, low-level seismicity continued at Shishaldin volcano. Elevated surface temperatures at the summit were detected. A steam and gas plume was intermittently visible rising from the summit and drifting downwind, although satellite and web-camera images have been mostly cloudy. 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.
Shiveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E, Summit elev. 3283 m
KVERT reported that during 20-27 June lava-dome extrusion onto Shiveluch’s SE flank was accompanied by ash explosions, incandescence, hot avalanches, and fumarolic activity. Satellite images detected a thermal anomaly over the dome on 22 and 25 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
The Buenos Aires VAAC reported that during 25-28 June there was continuous steam and possible ash emission from Ubinas. In a press release from 30 June, IGP noted minimal releases of ash and gas emissions had been observed during the previous days. Gas-and-ash plumes observed on 30 June rose 1.8 km above the crater. Minor ashfall was reported SE.
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.