Active volcanoes in the world: February 11 - 17, 2015

Active volcanoes in the world: February 11 - 17, 2015

New activity was observed at 9 volcanoes from February 11 - 17, 2015. During the same period, ongoing activity was observed at 13 volcanoes.

New activity/unrest: Chikurachki, Paramushir Island (Russia) | Colima, Mexico | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Klyuchevskoy, Central Kamchatka (Russia) | Pacaya, Guatemala | Piton de la Fournaise, Reunion Island (France) | Soputan, Sulawesi (Indonesia) | Villarrica, Chile

Ongoing activity: Aira, Kyushu (Japan) | Asosan, Kyushu (Japan) | Bardarbunga, Iceland | Chirpoi, Kuril Islands (Russia) | Dukono, Halmahera (Indonesia) | Kilauea, Hawaiian Islands (USA) | Kuchinoerabujima, Ryukyu Islands (Japan) | Popocatepetl, Mexico | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Sinabung, Indonesia | Suwanosejima, Ryukyu Islands (Japan) | Zhupanovsky, Eastern Kamchatka (Russia)

New activity/unrest

Chikurachki, Paramushir Island (Russia)
50.324°N, 155.461°E, Elevation 1781 m

According to KVERT, the Tokyo VAAC stated that an eruption at Chikurachki began at 1000 on 16 February. A Support to Aviation Control Service (SACS) notice described a large amount of aerosol near the Northern Kuriles Islands at 1322 that same day. Satellite images detected ash plumes that rose to altitudes of 7-7.5 km (23,000-24,600 ft) a.s.l. and drifted 80 km W. The Aviation Color Code was raised to Orange. At 0641, 1328, and 1635 on 17 February satellite images showed ash plumes rising to altitudes of 3-3.5 km (10,000-11,500 ft) a.s.l. and drifting 95-230 km SW.

Geologic summary: Chikurachki, the highest volcano on Paramushir Island in the northern Kuriles, is actually a relatively small cone constructed on a high Pleistocene volcanic edifice. Oxidized basaltic-to-andesitic scoria deposits covering the upper part of the young cone give it a distinctive red color. Frequent basaltic plinian eruptions have occurred during the Holocene. Lava flows from 1781-m-high Chikurachki reached the sea and form capes on the NW coast; several young lava flows also emerge from beneath the scoria blanket on the eastern flank. The Tatarinov group of six volcanic centers is located immediately to the south of Chikurachki, and the Lomonosov cinder cone group, the source of an early Holocene lava flow that reached the saddle between it and Fuss Peak to the west, lies at the southern end of the N-S-trending Chikurachki-Tatarinov complex. In contrast to the frequently active Chikurachki, the Tatarinov volcanoes are extensively modified by erosion and have a more complex structure. Tephrochronology gives evidence of only one eruption in historical time from Tatarinov, although its southern cone contains a sulfur-encrusted crater with fumaroles that were active along the margin of a crater lake until 1959.

Colima, Mexico
19.514°N, 103.62°W, Elevation 3850 m

Based on satellite images, the Washington VAAC reported that on 11 February continued discrete emissions from Colima drifted NE and dissipated after 55 km. On 14 February a small eruption recorded by the webcam produced gas emissions with a low ash content that rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted NNE.

In a 17 February bulletin, the Unidad Estatal de Protección Civil reported that Colima remained active, although there continued to be a slight decrease in the number and size of lava-block avalanches. Lava flows minimally advanced. Explosions continued but also decreased in intensity, producing ash plumes that rose 2-3 km above the crater. The lava dome had been partially destroyed, forming a carter about 140 m in diameter. Residents were warned not go within 5 km of the volcano.

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.

Fuego, Guatemala
14.473°N, 90.88°W, Elevation 3763 m

On 12 February INSIVUMEH reported that explosions from Fuego produced water vapor, gas, and ash plumes that rose 350-800 m above the crater and drifted E and S, and at times NW, drifting as high as 1.7 km. During 12-14 February explosions generated ash plumes that rose 800 m and drifted 10-11 km E and SE. Incandescent material was ejected 100-150 m above the crater, causing avalanches in the Trinidad (S) drainage. During 15-16 February block avalanches descended the Cenizas (SSW), Trinidad, and Las Lajas (SE) drainages. Ashfall was reported in Panimache (8 km SW), Sangre de Cristo (8 km WSW), San Pedro Yepocapa (8 km NW). In a special report on 16 February INSIVUMEH noted 4-6 explosions per hour, and ash plumes that rose, based on pilot reports, to altitudes of 7-9.1 km (23,000-30,000 ft) a.s.l. and drifted more than 15 km SW and W. Another special report issued on 17 February stated that 4-6 explosions per hour continued to be detected. Large amounts of ash formed mushroom-shaped clouds that rose 0.6-1.1 km above the crater and drifted over 15 km NW, W, SE, and S. Incandescent material was ejected 150 m above the crater, causing avalanches in the Trinidad, Ceniza, Las Lajas, and Santa Teresa drainages.

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)
54.049°N, 159.443°E, Elevation 1513 m

KVERT reported that during 6-13 February a moderate explosive eruption at Karymsky continued. Satellite images showed a thermal anomaly over the volcano on 6 February; weather prevented views of 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, 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.

Klyuchevskoy, Central Kamchatka (Russia)
56.056°N, 160.642°E, Elevation 4754 m

KVERT reported that during 6-13 February a Strombolian and Vulcanian eruption at Klyuchevskoy continued. Incandescence at the summit was visible and bombs were ejected 200-300 m above the crater. Explosions generated ash plumes that rose to altitudes of 5.5-6.5 km (18,000-21,300 ft) a.s.l.; ashfall was reported in Kozyrevsk Village (50 km W) on 7 February and Klyuchi Village (30 km NNE) on 11 February. A lava flow effused onto the E flank. Satellite images showed a daily, big, bright thermal anomaly over the volcano, and ash plumes drifting about 400 km mainly NW and N at altitudes of 5.5-6.5 km (18,000-21,300 ft) a.s.l.

On 15 February at 1035 the webcam recorded ash plumes rising to altitudes of 6-6.5 km (19,700-21,300 ft) a.s.l. and drifting 74 km E. At 1211, 1347, and 1524 ash plumes rose to an altitude of 8 km (26,200 ft) a.s.l. and drifted 110-232 km E and ESE. The Aviation Color Code was raised to Red. At 1656 ash plumes rose to altitudes of 7.5-7.8 km (24,600-25,600 ft) a.s.l. and drifted 232 km ESE. The Aviation Color Code was lowered to Orange. At 1512 on 16 February ash plumes identified in satellite images rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted 270 km S. The next day, at 0641, 1503, and 1505, ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted 114-240 km SE.

Geologic summary: Klyuchevskoy (also spelled 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. It 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 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 the 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.

Pacaya, Guatemala
14.381°N, 90.601°W, Elevation 2552 m

INSIVUMEH reported that during 12-13 February a series of weak explosions from Pacaya's Mackenney Crater generated dark gray ash plumes that rose 500-700 m above the crater and, along with fumarolic plumes, drifted 1.5 km S. During 14-15 February weak explosions continued to generate ash plumes; ash and fumarolic plumes drifted 800 m SE. The next day fumarolic and ash plumes drifted S and SW at a low altitude. During 16-17 February fumarolic plumes with small amounts of ash rose 100 m and drifted E.

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.

Piton de la Fournaise, Reunion Island (France)
21.244°S, 55.708°E, Elevation 2632 m

OVPDLF reported that during 11-13 February visibility of the eruption at Piton de la Fournaise that began on 4 February from vents located 100 m outside and to the W of Bory Crater was hampered by poor weather conditions; tremor remained elevated. Tremor began to decrease at 1700 on 15 February, intensely fluctuated, and then disappeared around 2230. Incandescence visible with a webcam likely indicated draining lava tubes.

Geologic summary: The massive Piton de la Fournaise basaltic shield volcano on the French island of Réunion in the western Indian Ocean is one of the world's most active volcanoes. Much of its more than 530,000-year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three calderas formed at about 250,000, 65,000, and less than 5000 years ago by progressive eastward slumping of the volcano. Numerous pyroclastic cones dot the floor of the calderas and their outer flanks. Most historical eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest caldera, which is 8 km wide and breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures on the outer flanks of the caldera. The Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris, monitors this very active volcano.

Soputan, Sulawesi (Indonesia)
1.108°N, 124.73°E, Elevation 1784 m

Based on information from PVMBG and weather models, the Darwin VAAC reported that during 11-12 February an eruption at Soputan generated ash plumes that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted almost 30 km SE. Ash was not identified in satellite images due to darkness and meteorological clouds.

Geologic summary: The small Soputan stratovolcano on the southern rim of the Quaternary Tondano caldera on the northern arm of Sulawesi Island is one of Sulawesi's most active volcanoes. The youthful, largely unvegetated volcano rises to 1784 m and is located SW of Sempu volcano. It was constructed at the southern end of a SSW-NNE trending line of vents. During historical time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.

Villarrica, Chile
39.42°S, 71.93°W, Elevation 2847 m

OVDAS-SERNAGEOMIN reported that activity significantly increased at Villarrica during 1-16 February, characterized by increased seismicity, crater incandescence, and explosions. On 6 February seismicity increased significantly, explosions occurred in the crater, and ash emissions rose above the crater rim. The Alert Level was raised to Yellow (the second lowest level on a four-color scale). DOAS (Differential Optical Absorption Spectrometry) data showed an average monthly sulfur dioxide emission value of 222 tons per day; a high value during this period of 450 tons per day was recorded on 11 February. The highest number of explosions, five per minute, during the period occurred on 16 February. Explosions ejected incandescent material out of the crater as far as 1 km onto the S flank. During an overflight on 16 February, supported by ONEMI, volcanologists observed the lava lake and recorded temperatures near 800 degrees Celsius, tephra in and around the active crater, and a diffuse layer of ash on the flanks.

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.

Ongoing activity

Aira, Kyushu (Japan)
31.593°N, 130.657°E, Elevation 1117 m

JMA reported that 36 explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m during 9-13 February. Incandescence from the crater was visible at night during 9-11 February, and inflation continued to be detected. The Alert Level remained at 3 (on a scale of 1-5). The TokyoVAAC reported that during 11-17 February plumes rose to altitudes of 1.8-3.7 km (6,000-12,000 ft) a.s.l. and drifted E and SE. On 17 February pilots observedash plumes that rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted SE.

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.

Asosan, Kyushu (Japan)
32.884°N, 131.104°E, Elevation 1592 m

JMA reported that, based on seismicity and infrasound data, the eruption from Asosan’s Nakadake Crater that began on 25 November 2014 continued intermittently during 9-13 February. Incandescent material was sometimes ejected onto the crater rim, and plumes rose 600 m above the crater. High-amplitude tremor continued. The Alert Level remained at 2 (on a scale of 1-5).

Geologic summary: The 24-km-wide Asosan caldera was formed during four major explosive eruptions from 300,000 to 90,000 years ago. These produced voluminous pyroclastic flows that covered much of Kyushu. The last of these, the Aso-4 eruption, produced more than 600 cu km of airfall tephra and pyroclastic-flow deposits. A group of 17 central cones was constructed in the middle of the caldera, one of which, Nakadake, is one of Japan's most active volcanoes. It was the location of Japan's first documented historical eruption in 553 AD. The Nakadake complex has remained active throughout the Holocene. Several other cones have been active during the Holocene, including the Kometsuka scoria cone as recently as about 210 CE. Historical eruptions have largely consisted of basaltic to basaltic-andesite ash emission with periodic strombolian and phreatomagmatic activity. The summit crater of Nakadake is accessible by toll road and cable car, and is one of Kyushu's most popular tourist destinations.

Bardarbunga, Iceland
64.63°N, 17.53°W, Elevation 2009 m

During 11-17 February, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga’s Holuhraun eruptive fissure; the overall activity was persistent, but lower compared to recent weeks and months. Seismicity remained strong. Local air pollution from gas emissions persisted and GPS measurements showed that subsidence continued. The lava field covered 85 square kilometers on 14 February; measurements from 4 and 12 February showed almost no changes in the extent of the field.

Geologic summary: The large central volcano of Bárdarbunga lies beneath the NW part of the Vatnajökull icecap, NW of Grímsvötn volcano, and contains a subglacial 700-m-deep caldera. Related fissure systems include the Veidivötn and Trollagigar fissures, which extend about 100 km SW to near Torfajökull volcano and 50 km NE to near Askja volcano, respectively. Voluminous fissure eruptions, including one at Thjorsarhraun, which produced the largest known Holocene lava flow on Earth with a volume of more than 21 cu km, have occurred throughout the Holocene into historical time from the Veidivötn fissure system. The last major eruption of Veidivötn, in 1477, also produced a large tephra deposit. The subglacial Loki-Fögrufjöll volcanic system located SW of Bárdarbunga volcano is also part of the Bárdarbunga volcanic system and contains two subglacial ridges extending from the largely subglacial Hamarinn central volcano; the Loki ridge trends to the NE and the Fögrufjöll ridge to the SW. Jökulhlaups (glacier-outburst floods) from eruptions at Bárdarbunga potentially affect drainages in all directions.

Chirpoi, Kuril Islands (Russia)
46.525°N, 150.875°E, Elevation 742 m

SVERT reported that satellite images over Snow, a volcano of Chirpoi, showed a thermal anomaly on 9 and 11 February. Cloud cover obscured views during 10 and 12-16 February. 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.

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 during 11 February ash plumes from Dukono rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted over 35 km S.

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.

Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Elevation 1222 m

During 11-17 February HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small breakouts across the interior and edges of the lobes, upslope of the leading front. Small brush fires from the breakouts were noted about 3 km NE of Pu'u 'O'o Crater and in an area W of the Kaohe Homesteads. The most northern lobe of lava remained about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra onto nearby areas.

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 9-16 January although the level of activity remained elevated. White plumes rose 400-700 m above the crater. Low-level seismicity continued and tremor was absent. Scientists aboard an overflight on 10 February observed a new crater with high-temperature areas on the NE part, new fissures, and white steam emissions. 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.

Popocatepetl, Mexico
19.023°N, 98.622°W, Elevation 5426 m

CENAPRED reported that during 10-11 and 11-12 February the seismic network at Popocatépetl recorded 146 and 101 low-intensity events, respectively, accompanied by steam-and-gas emissions that sometimes contained minor amounts of ash. Explosions were also detected, likely from lava-dome growth. On 11 February ashfall was reported in Puebla (~50 km to the E) and in the municipalities of Juan C. Bonilla, Domingo Arenas, Huejotzingo (27 km NE), and at the airport to the E. Intermittent nighttime incandescence from the crater was visible during 11-12 February.

During 13-17 February seismicity indicated ongoing emissions, and incandescence from the crater was noted. A series of explosions between 0650 and 1200 on 15 February generated plumes that rose 1.8 km above the crater and drifted NE. Ash fell in Huejotzingo, Domingo Arenas, Salvador el Verde (30 km NNE), San Felipe Teotlalcingo (26 km NNE) , and Puebla. Explosions continued to be detected; nine were registered during 16-17 February. 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 6-13 February lava-dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot block avalanches, andfumarolic activity. A strong explosion on 8 February generated ash plumes that rose to altitudes of 9-10 km (29,500-32,800 ft) a.s.l. and drifted 180 km NW. A thermal anomaly over the dome was detected daily. 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 11-17 February. Elevated surface temperatures were observed in satellite images on most days, and minor steam emissions were recorded by the web cam on 11 February. Low-level eruptive activity confined to the summit crater likely continued. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Geologic summary: The beautifully symmetrical volcano of Shishaldin is the highest and one of the most active volcanoes of the Aleutian Islands. The 2857-m-high, glacier-covered volcano is the westernmost of three large stratovolcanoes along an E-W line in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." A steady steam plume rises from its small summit crater. Constructed atop an older glacially dissected volcano, it is Holocene in age and largely basaltic in composition. Remnants of an older ancestral volcano are exposed on the west and NE sides at 1500-1800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is blanketed by massive aa lava flows. Frequent explosive activity, primarily consisting of strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century.

Sinabung, Indonesia
3.17°N, 98.392°E, Elevation 2460 m

Based on satellite images and weather models, the Darwin VAAC reported that during 11-12 February ash plumes from Sinabung rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted over 30 km 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 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.

Suwanosejima, Ryukyu Islands (Japan)
29.638°N, 129.714°E, Elevation 796 m

Based on JMA notices, the Tokyo VAAC reported that during 11-12 and 14-15 February ash plumes from Suwanosejima rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted E.

Geologic summary: The 8-km-long, spindle-shaped island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. 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. Suwanosejima, one of Japan's most frequently active volcanoes, was in a state of intermittent strombolian activity from 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 Otake 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. Only about 50 persons live on the island.

Zhupanovsky, Eastern Kamchatka (Russia)
53.589°N, 159.15°E, Elevation 2899 m

KVERT reported that a moderate explosive eruption at Zhupanovsky continued during 6-13 February. Satellite images detected a daily thermal anomaly over the volcano. Ash clouds rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted about 65 km W on 6 and 9 February. 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.

Source: GVP


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