Active volcanoes in the world: October 22 - 28, 2014

Active volcanoes in the world: October 22 - 28, 2014

New activity/unrest was observed at 6 volcanoes from October 22 - 28, 2014. Ongoing activity was reported for 10 volcanoes.

New activity/unrest: Chiles-Cerro Negro, Colombia-Ecuador  | Copahue, Central Chile-Argentina border  | Kilauea, Hawaiian Islands (USA)  | Mayon, Luzon (Philippines)  | Popocatepetl, Mexico  | Sinabung, Indonesia

Ongoing activity: Aira, Kyushu (Japan)  | Asosan, Kyushu (Japan)  | Bardarbunga, Iceland  | Dukono, Halmahera (Indonesia)  | Ontakesan, Honshu (Japan)  | Sabancaya, Peru  | Santa Maria, Guatemala  | Sheveluch, Central Kamchatka (Russia)  | Shishaldin, Fox Islands (USA)  | Zhupanovsky, Eastern Kamchatka (Russia)

New activity/unrest

Chiles-Cerro Negro, Colombia-Ecuador
0.817°N, 77.938°W, Summit elev. 4698 m

Based on reports from Observatorio Vulcanológico and Sismológico de Pasto (SGC-OVSP), and the Instituto Geofísico de la Escuela Politécnica Nacional (IGEPN), on 26 October Servicio Geológico Colombiano (SGC) stated that seismic activity at Cerro Negro de Mayasquer and Chiles volcanoes continued at a high rate. Since 29 September 2014 about 81,000 earthquakes had been detected with 6,300 of those events occurring on 25 October. The epicenter was 2-3.5 km S of Chiles. Interferometry (INSAR) and a high resolution GPS network both showed localized deformation S of Chiles. The Alert Level remained at Orange (level 3 of 4).

A news article from 23 October noted that 3,500 families had been evacuated from the Chiles, Panam, and Mayasquer communities.

Geologic summary: The Chiles-Cerro Negro volcanic complex includes both the Pleistocene Chiles and the Cerro Negro de Mayasquer stratovolcanoes astride the Colombia-Ecuador border. Cerro Negro has a caldera open to the west, with andesitic and dacitic lava flows of possible Holocene age (Hall 1992, pers. comm.) and solfataras on the shore of a small crater lake. An eruption reported in 1936 may have been from Reventador (Catalog of Active Volcanoes of the World). The higher, glacier-covered summit of Chiles, about 4 km ESE of Cerro Negro, last erupted about 160,000 years ago, but it has a caldera open to the north with hot springs and an active hydrothermal system on its eastern flank.

Copahue, Central Chile-Argentina border
37.856°S, 71.183°W, Summit elev. 2953 m

On 24 October SERNAGEOMIN reported a continuing downward trend of seismicity at Copahue and that emissions had become more diffuse with only minute amounts of tephra in some plumes. A small mud lake had also formed in the crater. SERNAGEOMIN lowered the Alert Level to Yellow and recommended no entry into a restricted area within 3 km of the crater. ONEMI maintained Level Yellow for Alto Biobío (40 km W) in the Biobío region (since 3 June 2013).

Geologic summary: Volcán Copahue is an elongated composite cone constructed along the Chile-Argentina border within the 6.5 x 8.5 km wide Trapa-Trapa caldera that formed between 0.6 and 0.4 million years ago near the NW margin of the 20 x 15 km Pliocene Caviahue (Del Agrio) caldera. The eastern summit crater, part of a 2-km-long, ENE-WSW line of nine craters, contains a briny, acidic 300-m-wide crater lake (also referred to as El Agrio or Del Agrio) and displays intense fumarolic activity. Acidic hot springs occur below the eastern outlet of the crater lake, contributing to the acidity of the Río Agrio, and another geothermal zone is located within Caviahue caldera about 7 km NE of the summit. Infrequent mild-to-moderate explosive eruptions have been recorded at Copahue since the 18th century. Twentieth-century eruptions from the crater lake have ejected pyroclastic rocks and chilled liquid sulfur fragments.

Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Summit elev. 1222 m

During 22-28 October HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. On 22 October a narrow lava flow (less than 50 m wide) that had overtaken the flow front during the previous few days moved into a small gully; the advancement rate was variable and sometimes as high as 300 m/day. Another breakout upslope continued to advance at a slower rate. On 24 October HVO scientists aboard an overflight measured the cross sectional area of the lava tube feeding the flow; the measurement suggested that the volume of lava being supplied to the flow from the Pu'u 'O'o vent had slightly increased.

At approximately 0350 on 25 October lava crossed Apa’a Street and continued to advance towards Pahoa town. Throughout the morning the flow moved down the Pahoa cemetery driveway and then turned SE into adjoining pasture. At 0900 on 26 October the flow was an estimated 140 m wide. The next day it had narrowed to 100 m wide and was about 570 m from Pahoa Village Road. At about 0200 on 28 October the flow had reached the first occupied residential property. The leading edge of the flow was less than 50 m wide but increased to 150 m upslope. At 1730 the lava flow was 310 m in a straight-line distance from Pahoa Village Road and about 900 meters in a straight-line distance from Highway 130. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

According to news articles, Pahoa town, residence to 800-900 people, consists of small shops and homes. A school and a few roads were closed. Crews were building temporary access roads and trying to build berms to divert lava away from the highly traveled Highway 130.

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 tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

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.

Mayon, Luzon (Philippines)
13.257°N, 123.685°E, Summit elev. 2462 m

PHIVOLCS reported that during 22-28 October white plumes rose from Mayon's crater and drifted SW, WSW, WNW, and NW. A few volcanic earthquakes and rockfall signals were recorded during 23-25 and 28 October. Weak crater incandescence from the crater was noted at night on 22, 25, and 27 October. The Alert Level remained at 3 (on a 0-5 scale).

Geologic summary: Beautifully symmetrical Mayon volcano, which rises to 2462 m above the Albay Gulf, is the Philippines' most active volcano. The structurally simple volcano has steep upper slopes averaging 35-40 degrees that are capped by a small summit crater. Historical eruptions at this basaltic-andesitic volcano date back to 1616 and range from strombolian to basaltic plinian, with cyclical activity beginning with basaltic eruptions, followed by longer term andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic flows and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often devastated populated lowland areas. Mayon's most violent eruption, in 1814, killed more than 1200 people and devastated several towns.

Popocatepetl, Mexico
19.023°N, 98.622°W, Summit elev. 5426 m

CENAPRED reported that during 22-28 October seismicity at Popocatépetl indicated continuing emissions of water vapor, gas, and small amounts of ash. Incandescence from the crater was observed at night. A small explosion at 0317 on 25 October ejected tephra 100 m onto the S flank. A steam-and-gas plume containing a small amount of ash rose 1.5 km above the crater and drifted SW. Ashfall was reported in Tetela del Volcán (20 km SW). An explosion at 0111 on 26 October ejected tephra 200 m onto the N flank. A steam-and-gas plume with diffuse ash rose 1.1 km and drifted NW. On 28 October an ash plume drifted WSW. The Alert Level remained at to 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.

Sinabung, Indonesia
3.17°N, 98.392°E, Summit elev. 2460 m

Based on webcam views, wind data models, and satellite images, the Darwin VAAC reported that during 23-27 October ash plumes rose from Sinabung. During 23-24 October ash plumes drifted 15-40 km N and SW. A small eruption observed on the webcam on 25 October produced a minor amount of ash that drifted SW; a later ash plume drifted almost 30 km WNW. The next day another eruption generated an ash plume that drifted E. Ash emissions on 27 October were recorded by the webcam. The VAAC noted that PVMBG reported an ash plume that rose to an altitude of 5.5 km (18,000 ft) a.s.l. and then dissipated.

On 27 October BNPB reported that activity at Sinabung remained high; on 26 October pyroclastic flows traveled 3.5 km S and avalanches occurred multiple times. Hot ash clouds rose 2 km. The report stated that 3,284 people from 1,018 families remained in evacuation shelters.

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.

Ongoing activity

Aira, Kyushu (Japan)
31.593°N, 130.657°E, Summit elev. 1117 m

JMA reported that two explosions from Showa Crater at Aira Caldera’s Sakurajima volcano were detected during 20-24 October; an explosion on 24 October generated a plume that rose 3.2 km. The Alert Level remained at 3 (on a scale of 1-5). The Tokyo VAAC reported that on 24 October ash plumes rose to altitudes of 3-4.6 km (10,000-15,000 ft) a.s.l. and drifted E. During 25-26 October plumes rose to altitudes of 2.4-2.7 km (8,000-9,000 ft) a.s.l. and drifted E. On 28 October plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted S.

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, Summit elev. 1592 m

JMA reported that a period of tremor from a very small eruption at Asosan was recorded late at night on 22 October through early the next morning. The video camera near the crater had ash adhered to it. During a field survey on 24 October volcanologists observed ashfall around Nakadake Crater. 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, Summit elev. 2009 m

JMA reported that a period of tremor from a very small eruption at Asosan was recorded late at night on 22 October through early the next morning. The video camera near the crater had ash adhered to it. During a field survey on 24 October volcanologists observed ashfall around Nakadake Crater. The Alert Level remained at 2 (on a scale of 1-5).

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.

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 28 October ash plumes from Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted almost 85 km 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. 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.

Ontakesan, Honshu (Japan)
35.893°N, 137.48°E, Summit elev. 3067 m

JMA reported that cloud cover often prevented visual observations of Ontakesan during 22-28 October; white plumes were periodically observed rising 100-300 m above the crater rim and drifting E and SE. Seismicity remained low. The Alert Level remained at 3 (on a scale of 1-5).

Geologic summary: The massive Ontakesan stratovolcano, the second highest volcano in Japan, lies at the southern end of the Northern Japan Alps. Ascending this volcano is one of the major objects of religious pilgrimage in central Japan. It is constructed within a largely buried 4 x 5 km caldera and occupies the southern end of the Norikura volcanic zone, which extends northward to Yakedake volcano. The older volcanic complex consisted of at least four major stratovolcanoes constructed from about 680,000 to about 420,000 years ago, after which Ontakesan was inactive for more than 300,000 years. The broad, elongated summit of the younger edifice is cut by a series of small explosion craters along a NNE-trending line. Several phreatic eruptions post-date the roughly 7300-year-old Akahoya tephra from Kikai caldera. The first historical eruption took place in 1979 from fissures near the summit. A non-eruptive landslide in 1984 produced a debris avalanche and lahar that swept down valleys south and east of the volcano. Very minor phreatic activity caused a dusting of ash near the summit in 1991 and 2007. A significant phreatic explosion in September 2014, when a large number of hikers were at or near the summit, resulted in many fatalities.

Sabancaya, Peru
15.78°S, 71.85°W, Summit elev. 5967 m

IGP reported that during 21-27 October seismic activity at Sababcaya was low, and sporadic white and blue plumes rose as high as 1.2 km. Although a pilot reported an ash plume drifting E on 23 October, the Buenos Aires VAAC reported that ash was not detected in satellite images. The webcam showed gas-and-steam emissions, likely with diffuse ash, dissipating near the summit. On 25 October a pilot reported ash drifting E, but again satellite images did not detected ash.

Geologic summary: Sabancaya, located on the saddle between 6288-m-high Ampato and 6025-m-high Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three volcanoes, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. Both Nevado Ampato and Nevado Sabancaya are only slightly affected by glacial erosion and consist of a series of lava domes aligned along a NW-SW trend. The name of 5967-m-high Sabancaya (meaning "tongue of fire" in the Quechua Indian language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of historical eruptions date back to 1750.

Santa Maria, Guatemala
14.756°N, 91.552°W, Summit elev. 3772 m

INSIVUMEH reported that during 22-23 October avalanches originated from the lava-flow front active on the S flank of Santa María's Santiaguito lava-dome complex. Phreatic explosions occurred at the middle and lower parts of the lava flow. On 24 October a lahar descended the San Isidro (SW) drainage, a tributary of the Tambor River, carrying blocks 1-2 m in diameter. During 25-26 October a dense white plume rose 500 m and drifted SW. The most active part of the lava flow advanced S down the Nima I drainage. Another part had advanced 3 km E and was active in the San José finca. Block avalanches were produced from the lava-flow fronts.

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.

Sheveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E, Summit elev. 3283 m

KVERT reported that during 17-24 October lava-dome extrusion onto Sheveluch’s N flank was accompanied by ash explosions, incandescence, hot avalanches, and fumarolic activity. Satellite images detected a thermal anomaly over the dome during 17, 20, and 22 October; cloud cover prevented views of the volcano on the other days. 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, Summit elev. 2857 m

AVO reported that partly cloudy satellite images and mostly cloudy webcam views showed nothing unusual at Shishaldin during 21-24 October. Seismicity increased on 25 October, and was followed by a tremor event and elevated surface temperatures detected at the summit in satellite images. Tephra deposits at the summit were noted in clear webcam images on 26 October, indicating that the event was energetic enough to eject material onto the flank from a depth of several hundred meters within the summit crater. 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, Summit elev. 2899 m

KVERT reported that an eruption at Zhupanovsky likely continued during 17-24 October. Satellite images were obscured by clouds. 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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