Active volcanoes in the world: October 29 - November 4, 2014

Active volcanoes in the world: October 29 - November 4, 2014

New activity/unrest was observed at 4 volcanoes from October 29 - November 4, 2014. Ongoing activity was reported for 10 volcanoes.

New activity/unrest: Kilauea, Hawaiian Islands (USA) | Popocatepetl, Mexico | Sinabung, Indonesia | Turrialba, Costa Rica

Ongoing activity: Aira, Kyushu (Japan) | Bardarbunga, Iceland | Batu Tara, Komba Island (Indonesia) | Dukono, Halmahera (Indonesia) | Mayon, Luzon (Philippines) | Ontakesan, Honshu (Japan) | Santa Maria, Guatemala | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Zhupanovsky, Eastern Kamchatka (Russia)

New activity/unrest

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

During 29 October-4 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. Breakout lava flows behind the stalled leading edge continued to advance; during 30-31 October a lobe downslope of the Pahoa cemetery was active, burning trees in a forested area and causing numerous loud methane bursts. The lobe entered residential property at 1645 on 31 October, advanced along the N edge of the property, and then stalled on 4 November. The interior areas of the flows continued to inflate.

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 ventcontinued 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.

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

CENAPRED reported that during 29 October-4 November seismicity at Popocatépetl indicated continuing emissions of water vapor, gas, and small amounts of ash. Incandescence from the crater was observed most nights. The seismic network detected nine explosions during 29-30 October and two explosions on 31 October; ash plumes rose as high as 1.2 km and drifted SW. Ash plumes rose 1 km and drifted E on 1 November and SW on 3 November. Periodic ejections of incandescent tephra landed 600 m away on the E and N crater flanks on 4 November. Ash plumes rose 1 km. 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, Elevation 2460 m

Based on a pilot observation, the Darwin VAAC reported localized ash from Sinabung on 2 November, but a meteorological cloud in the area prevented further observations. A pyroclastic flow and an ash plume were recorded by the webcam on 3 November. The ash plume rose to an estimated altitude of 4.6 km (15,000 ft) a.s.l. and drifted NE; the altitude of the ash plume was again uncertain due to meteorological cloud. On 4 November an ash plume observed with the webcam rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted N.

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.

Turrialba, Costa Rica
10.025°N, 83.767°W, Elevation 3340 m

OVSICORI-UNA reported that seismic activity at Turrialba had started to increase in late September, and then in mid-October a three-day swarm of volcano-tectonic earthquakes was recorded. The largest event, a M 2.8, occurred at 2035 on 16 October at a depth of 5 km beneath the active crater. Magmatic degassing intensified during 28-29 October; sulfur dioxide flux was 2,000 tons per day, higher than the 1,300 tons per day average measured in September and the highest so far during 2014. During the morning of 29 October a seismologist noted a tremor signal which increased in amplitude during the afternoon and evening. An observer at a lodge noted that the gas plume was darker than usual with some ash. At 2310 a small phreatomagmatic eruption from the West Crater lasted about 25 minutes and ended with a strong explosion heard by nearby villagers. An ash cloud rose to an altitude of 5.8 km (19,000 ft) a.s.l. and drifted WSW. Ash fell in San Gerardo de Irazú, San Ramón de Tres Ríos, Coronado, Moravia, Curridabat, Desamparados, Aserrí, Escazú, Santa Ana, Belén, Guácima de Alajuela, Río Segundo de Alajuela, San Pedro Montes de Oca, Guadalupe, areas of Heredia, and the capital of San José (70 km W). The eruption destroyed the wall between the West and Central craters, depositing material around the Central Crater and partially burying it. According to a news report 11 people from Santa Cruz de Turrialba were evacuated to shelters and the national park was closed. Some schools were also temporarily closed, affecting over 300 area students.

The eruption continued during 30-31 October; analyses of collected tephra showed that the proportion of juvenile material increased its volume from 3-5% on 30 October to 7-10% the next day. Magma had not previously reached the surface at Turrialba since an eruption in 1866.

An explosion at 0520 on 1 November generated an ash plume that drifted towards the E and N parts of the Central Valley. A 3 November report stated that during the previous 24 hours seismicity had decreased significantly and no explosions were detected; seismicity remained elevated as compared to levels detected prior to the current activity. An online tool that allowed residents to note if they had observed ashfall during 31 October-4 November showed a dispersion pattern in the Central Valley W and NW of Turrialba.

Geologic summary: Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.

Ongoing activity

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

The Tokyo VAAC reported an explosion from Showa Crater at Aira Caldera’s Sakurajima volcano on 1 November. Explosions on 2 November generated ashplumes that rose to altitudes of 2.4-3 m (8,000-10,000 ft) a.s.l. and drifted E and SE. During 3-4 November ash plumes rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted S and W.

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.

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

During 29 October-4 November, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga’s Holuhraun eruptive fissure. Subsidence of the Bárdarbunga Caldera continued; by 31 October the depression was about 42 m. The lava field was 65.7 square kilometers on 31 October.

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.

Batu Tara, Komba Island (Indonesia)
7.792°S, 123.579°E, Elevation 748 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 1 November ash plumes from Batu Tara rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted almost 95 km NE.

Geologic summary: The small isolated island of Batu Tara in the Flores Sea about 50 km north of Lembata (fomerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks of Batu Tara to within 50 m of the 748-m-high summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption from Batu Tara, during 1847-52, produced explosions and a lava flow.

Dukono, Halmahera (Indonesia)
1.68°N, 127.88°E, Elevation 1335 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 29 October ash plumes from Dukono rose to altitudes of 2.4 km (8,000 ft) a.s.l. and drifted 75 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.

Mayon, Luzon (Philippines)
13.257°N, 123.685°E, Elevation 2462 m

PHIVOLCS reported that during 28 October-4 November white plumes rose from Mayon's crater and drifted SW, WSW, WNW, and NW, sometimes down the flanks. Weak incandescence from the crater was noted at night on 28 October. A few volcanic earthquakes and rockfall signals were recorded during 29-31 October and 4 November. A 4 November report noted that ground deformation had been detected since the beginning of 2014. Tilt data from the network on the NW flank indicated continuing inflation since August, subsequent to a period of inflation in June and July. The inflation events were thought to correspond to amagma body, approximately 107 cubic meters, slowly intruding at depth. Precise leveling measurements also indicated sustained inflation. 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.

Ontakesan, Honshu (Japan)
35.893°N, 137.48°E, Elevation 3067 m

JMA reported that cloud cover often prevented visual observations of Ontakesan during 29 October-4 November; white plumes rose 100-300 m above the crater rim and drifted NE and SE during 29-30 October and 4 November. 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. 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. A non-eruptive landslide in 1984 produced a debris avalanche and lahar that swept down valleys south and east of the volcano. Ascending this volcano is one of the major objects of religious pilgrimage in central Japan.

Santa Maria, Guatemala
14.756°N, 91.552°W, Elevation 3772 m

INSIVUMEH reported that during 1-4 November ash plumes from the active lava-flow front on the S flank of Santa María's Santiaguito lava-dome complex rose 200 m. Explosions during 3-4 November rose 500 m and drifted SW, producing ashfall in Monte Claro (S) and mountainous areas of Palajunoj village (18 km SSW).

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, Elevation 3283 m

KVERT reported that during 24-31 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 27 and 29-30 October; cloud cover prevented views of the volcano on the other days. Strong explosions on 28 and 30 October generated ash plumes that rose to altitudes of 11 km (36,000 ft) a.s.l. and 7-8 km (23,000-26,200 ft) a.s.l., respectively. Ash plumes on those two days drifted more than 500 km NE. 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 mostly cloudy satellite and webcam views showed nothing unusual at Shishaldin during 29 October-4 November, although the low-level eruptive activity continued. Periods of tremor were detected and overall seismicity remained elevated. The Aviation Color Code remained at Orange and theVolcano 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 the eruption at Zhupanovsky had likely finished in mid-October; satellite images last detected an explosion on 11 October and a thermal anomaly on 12 October. Volcanologists conducting an overflight on 17 October observed only gas-and-steam activity from the active crater. The Aviation Color Code was lowered to Yellow.

Geologic summary: The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated volcanic complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene, the fourth is Holocene in age and was the source of all of Zhupanovsky's historical eruptions. An early Holocene stage of frequent moderate and weak eruptions from 7000 to 5000 years before present (BP) was succeeded by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption 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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