New activity/unrest was observed at 2 volcanoes from March 25 - 31, 2015. During the same period, ongoing activity was observed at 11 volcanoes.
New activity/unrest: Chirinkotan, Kuril Islands (Russia) | Villarrica, Chile.
Ongoing activity: Bagana, Bougainville (Papua New Guinea) | Chirpoi, Kuril Islands (Russia) | Colima, Mexico | Dukono, Halmahera (Indonesia) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaiian Islands (USA) | Kuchinoerabujima, Ryukyu Islands (Japan) | Popocatepetl, Mexico | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Zhupanovsky, Eastern Kamchatka (Russia).
Chirinkotan, Kuril Islands (Russia)
48.98°N, 153.48°E, Elevation 724 m
SVERT reported that on 27 March a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 23-30 March. The Aviation Color Code remained at Yellow.
Geologic summary: The small, mostly unvegetated 3-km-wide island of Chirinkotan occupies the far end of an E-W-trending volcanic chain that extends nearly 50 km west of the central part of the main Kuril Islands arc. Chirinkotan is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. A small 1-km-wide caldera about 300-400 m deep is open to the SE. Lava flows from a cone within the breached crater reached the north shore of the island. Historical eruptions have been recorded at Chirinkotan since the 18th century. Fresh lava flows also descended the SE flank of Chirinkotan during an eruption in the 1880s that was observed by the English fur trader Captain Snow.
39.42°S, 71.93°W, Elevation 2847 m
OVDAS-SERNAGEOMIN reported that during 24-25 March gas-and-ash emissions at Villarrica decreased but the magnitude of the continuous seismic tremor slightly increased. Crater incandescence overnight was observed. By the evening of 25 March Strombolian activity was confined to the crater and a gas plume rose 700 m above the crater rim. Seismicity fluctuated but increase overall. The lava lake had returned and was about 1,000 degrees Celsius. During 26-27 March Strombolian activity ejected tephra out of the crater to distances of about 500 m, and a gas plume rose more than 800 m. During an overflight on 27 March scientists noted that material which measured 1,110 degree Celsius originated from two vents. During 28-31 March a gas-and-ash plume rose from the crater and Strombolian explosions ejected tephra from the crater; several explosions starting at 2200 on 30 March, and continuing the next morning, ejected tephra 300 m above the crater and as far as 500 m from the crater onto the flanks. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public was warned to stay outside of a 5-km radius around the crater and away from drainages.
Geologic summary: Glacier-clad Villarrica, one of Chile's most active volcanoes, rises above the lake and town of the same name. It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain. A 6-km wide caldera formed during the late Pleistocene. A 2-km-wide caldera that formed about 3500 years ago is located at the base of the presently active, dominantly basaltic to basaltic-andesitic cone at the NW margin of the Pleistocene caldera. More than 30 scoria cones and fissure vents dot Villarrica's flanks. Plinian eruptions and pyroclastic flows that have extended up to 20 km from the volcano have been produced during the Holocene. Lava flows up to 18 km long have issued from summit and flank vents. Historical eruptions, documented since 1558, have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Glaciers cover 40 sq km of the volcano, and lahars have damaged towns on its flanks.
Bagana, Bougainville (Papua New Guinea)
6.137°S, 155.196°E, Elevation 1855 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 26 March a low-level ash plume from Bagana drifted 37 km NE. During 27-29 March ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 55 km NE and N. On 1 April an ash plume drifted 75 km SE.
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.
Chirpoi, Kuril Islands (Russia)
46.525°N, 150.875°E, Elevation 742 m
SVERT reported that satellite images over Snow, a volcano of Chirpoi, detected a thermal anomaly during 26-27 March, and gas-and-steam emissions on 29 March. Cloud cover obscured views on other days during 23-30 March. 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.
19.514°N, 103.62°W, Elevation 3850 m
Based on satellite images, Mexico City MWO, Colima Observatory notices, and webcam views, the Washington VAAC reported multiple ash emissions per day from Colima during 24-30 March. Gas-and-ash plumes on 24 March drifted E and dissipated around 90 km away. During 25-30 March some ash plumes rose to altitudes of 4-7.6 km (13,000-25,000 ft) a.s.l.; ash emissions drifted 15-140 km NE, ENE, E, and SE. Ash plumes on 30 March also drifted W.
Geologic summary: The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.
Dukono, Halmahera (Indonesia)
1.68°N, 127.88°E, Elevation 1335 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 25 March ash plumes from Dukono drifted 35-45 km W and NE. During 29-30 March ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted over 90 km NW and W.
Geologic summary: Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the north-flank cone of Gunung Mamuya. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.
Karymsky, Eastern Kamchatka (Russia)
54.049°N, 159.443°E, Elevation 1513 m
KVERT reported that during 20-27 March moderate activity at Karymsky continued. Satellite images detected ash plumes drifting 154 km E during 22 and 24-25 March, and a thermal anomaly over the volcano during 24-26 March. 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, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the 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, Elevation 1222 m
During 25-31 March HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with four separate breakouts in three areas within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a (burning trees were visible), and a relatively small breakout 5-6 km farther NE of Pu'u 'O'o. On 25 March HVO lowered the Volcano Alert Level from Warning to Watch, noting that in recent weeks the Pu'u 'O'o lava flows nearest to the town of Pahoa were inactive. The Aviation Color Code remained at Orange. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated.
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.
Kuchinoerabujima, Ryukyu Islands (Japan)
30.443°N, 130.217°E, Elevation 657 m
JMA reported that no eruptions occurred from Kuchinoerabujima during 27-30 March, although the level of activity remained elevated. White plumes rose 1 km above Shindake Crater. Continuing fumarolic actiivty in a crack in W part of the crater was confirmed during a field survey. In addition the temperature of a thermal anomaly in the W part continued to rise. Low-level seismicity continued. The Alert Level remained at 3 (on a scale of 1-5).
Geologic summary: A group of young stratovolcanoes forms the eastern end of the irregularly shaped island of Kuchinoerabujima in the northern Ryukyus, 15 km west of Yakushima. Furutake, Shintake, and Noike were erupted from south to north, respectively, to form a composite cone that is parallel to the trend of the Ryukyu Islands. The highest peak, Furutake, reaches only 657 m above sea level. The youngest cone, 640-m-high Shintake, was formed after the NW side of Furutake was breached by an explosion. All historical eruptions have occurred from Shintake, although a lava flow from the S flank of Furutake that reached the coast has a very fresh morphology. Frequent explosive eruptions have taken place from Shintake since 1840; the largest of these was in December 1933. Several villages on the 4 x 12 km island are located within a few kilometers of the active crater and have suffered damage from eruptions.
19.023°N, 98.622°W, Elevation 5426 m
At 2113 on 24 March activity at Popocatépetl increased and a four-hour series of explosions produced steam, gas, and ash emissions that rose 3 km. Incandescent tephra was ejected 800 m onto the NE and SE flanks. The last explosion in the series was detected at 0118 on 25 March. Additional explosion on 25 March ejected tephra and generated steam, gas, and ash plumes; the plumes rose 2 km and drifted NE and SE causing ashfall in Atlixco, Puebla. During 26-31 March the seismic network recorded between 21 and 86 emissions per day that sometimes contained ash. Cloud cover often prevented observations of the crater, although ash plumes and nighttime crater incandescence were noted. Continuous steam, gas, and ash emissions on 26 March rose 600 m and drifted ENE. On 29 March at 0944 an ash plume rose 2 km. On 31 March one of three explosions, which occurred at 0740, generated an ash plume that rose less than 1 km and drifted SW. 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, Elevation 3283 m
KVERT reported that during 20-27 March lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot block avalanches, and fumarolic activity. Strong explosions on 20, 22, and 25 March generated ash plumes that rose to altitudes of 7-10 km (23,000-32,800 ft) a.s.l. Ash plumes visible in satellite images drifted more than 600 km N, E, and SE during 20-22 and 25-26 March. A daily thermal anomaly was also visible in satellite images. 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, Elevation 2857 m
AVO reported that seismicity at Shishaldin continued to be elevated over background levels during 25-31 March, indicating that low-level eruptive activity confined to the summit crater likely continued. Nothing significant was observed in partly-to-mostly cloudy satellite and web camera images. Vigorous steaming at the summit was visible during 28 and 30-31 March; steam plumes, also reported by a pilot, rose several hundred feet above the crater on 30 March, and on 31 March observers on a Coast Guard ship reported that a steam-rich plume drifted 15-30 km S. 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.
Zhupanovsky, Eastern Kamchatka (Russia)
53.589°N, 159.15°E, Elevation 2899 m
KVERT reported that a moderate explosive eruption at Zhupanovsky continued during 20-27 March. Based on observers and webcam recordings, explosions produced ash plumes that rose to an altitude of 8 km (26,200 ft) a.s.l. on 25 March and drifted more than 100 km ENE. A daily thermal anomaly was detected in satellite images. The Aviation Color Code remained at Orange.
Geologic summary: The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated volcanic complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene, the fourth is Holocene in age and was the source of all of Zhupanovsky's historical eruptions. An early Holocene stage of frequent moderate and weak eruptions from 7000 to 5000 years before present (BP) was succeeded by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption took place about 800-900 years BP. Historical eruptions have consisted of relatively minor explosions from the third cone.