Active volcanoes in the world: October 16 – October 22, 2013

During past seven days 7 volcanoes had new activity, ongoing activity was reported for 6 volcanoes. This report covers active volcanoes in the world from October 16 – October 22, 2013 based on Smithsonian/USGS criteria.

New activity/unrest: | Barren Island, Andaman Islands | Kliuchevskoi, Central Kamchatka (Russia) | Semeru, Eastern Java (Indonesia) | Shiveluch, Central Kamchatka (Russia) | Tungurahua, Ecuador | Veniaminof, Alaska Peninsula | White Island, New Zealand

Ongoing activity: | Chirinkotan, Kuril Islands | Dukono, Halmahera | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Sakura-jima, Kyushu | Suwanose-jima, Ryukyu Islands and Kyushu

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 23:00 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.

New activity/unrest

BARREN ISLAND, Andaman Islands 
12.278°N, 93.858°E; summit elev. 354 m

Based on analysis of satellite imagery and wind data, the Darwin VAAC reported that on 17 October an ash plume from Barren Island rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted less than 30 km NW.

Geologic summary: Barren Island, a possession of India in the Andaman Sea about 135 km NE of Port Blair in the Andaman Islands, is the only historically active volcano along the N-S-trending volcanic arc extending between Sumatra and Burma (Myanmar). The 354-m-high island is the emergent summit of volcano that rises from a depth of about 2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-km-wide caldera with walls 250-350 m high. The caldera, which is open to the sea on the W, was created during a major explosive eruption in the late Pleistocene that produced pyroclastic-flow and -surge deposits. The morphology of a fresh pyroclastic cone that was constructed in the center of the caldera has varied during the course of historical eruptions. Lava flows fill much of the caldera floor and have reached the sea along the western coast during historical eruptions.

KLIUCHEVSKOI, Central Kamchatka (Russia) 
56.057°N, 160.638°E; summit elev. 4850 m

KVERT reported that a strong explosion from a new cinder cone low on Kliuchevskoi’s SW flank occurred between 2020 and 2030 on 11 October. An ash plume rose to altitudes of 6-7 km (19,700-23,000 ft) a.s.l. and drifted E.

Activity increased on 15 October, prompting KVERT to raise the Aviation Color Code to Red at 1311. Ash plumes rose to altitudes of 7-8 km (23,000-26,200 ft) a.s.l. and drifted 140 km SSW. Phreatic explosions on the SW flank generated ash plumes that rose 3-4 km (9,800-13,100 ft) a.s.l. Satellite images showed an ash plume rising to an altitude of 7.5 km (24,600 ft) a.s.l. at 1419 and drifting 103 km SSW. Activity increased again; ash plumes rose to altitudes of 9 km (29,500 ft) a.s.l. at 1655 and 10 km (32,800 ft) a.s.l. afterwards. Ash plumes drifted SSW and S. At 2056 KVERT lowered the Aviation Color Code to Orange and noted that although activity had slightly decreased it still remained high. Ash plumes rose 8 km (26,200 ft) a.s.l. and drifted ENE. Phreatic explosions at the SW flank continued, as well as lava flows on the SW, W, and SE flanks.

At 0815 on 16 October satellite images detected ash plumes that rose to altitudes of 2-3 km (6,600-9,800 ft) a.s.l. and drifted 480 km NNW. Activity again increased and at 1143 KVERT issued a notice stating that the Aviation Color Code was again being raised to Red. Seismic data indicated that ash plumes rose to an altitude of 10 km (32,800 ft) a.s.l. Clouds prevented direct observations but satellite images showed ash plumes drifting NW. At 1624 satellite images showed ash plumes drifting WSW at altitudes of 7-7.5 km (23,000-24,600 ft) a.s.l. Strombolian and Vulcanian explosions continued. Activity again slightly decreased; the Aviation Color Code was lowered to Orange. Minor ashfall was reported in Mayskoe Village.

During 16-17 October the melting of the Bogdanovich glacier due to the volcanic activity caused increased water flow in the Studenaya River, which destroyed part of a road near Kozyrevsk village (about 50 km W).

On 18 October the Aviation Color Code was again raised to Red but lowered to Orange later that day. Ash plumes rose to altitudes of 8-9 km (26,200-29,500 ft) a.s.l. and drifted 20-100 km SE. Strombolian activity continued and several lava flows continued to effuse onto the W, SW, and SE flanks. At 0559 on 19 October ash plumes observed in satellite images drifted 630 km SE at altitudes of 8-9 km (26,200-29,500 ft) a.s.l. The Aviation Color Code was raised to Red. Ash plume altitudes fluctuated between 7-8 km (23,000-26,200 ft) a.s.l. later that day. A large amount of ash continued to drift 600 km SE. At 0100 on 21 October a sharp decrease in seismicity was detected and only fumarolic activity was observed. The Aviation Color Code was lowered to Orange.

Geologic summary: 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. Kliuchevskoi 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 at Kliuchevskoi 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 its 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.

SEMERU, Eastern Java (Indonesia) 
8.108°S, 112.92°E; summit elev. 3676 m

The Darwin VAAC reported that on 18 October a pilot saw a low-level ash plume from Semeru. Ash was not identified in satellite images.

Geologic summary:  Semeru is the highest volcano on Java and one of its most active. The symmetrical stratovolcano rises abruptly to 3,676 m above coastal plains to the S and lies at the southern end of a volcanic massif extending N to the Tengger caldera. Semeru has been in almost continuous eruption since 1967. Frequent small-to-moderate Vulcanian eruptions have accompanied intermittent lava dome extrusion, and periodic pyroclastic flows and lahars have damaged villages below the volcano. A major secondary lahar on 14 May 1981 caused more than 250 deaths and damaged 16 villages.

SHIVELUCH, Central Kamchatka (Russia) 
56.653°N, 161.360°E; summit elev. 3283 m

Based on visual observations and analyses of satellite data, KVERT reported that during 11-18 October a viscous lava flow effused onto the N and NE flanks of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, ash explosions, and fumarolic activity. A thermal anomaly was detected daily in satellite images.

At 1528 on 18 October video data showed ash plumes rising to altitudes of 9-10 km (29,500-32,800 ft) a.s.l. Several explosions during 1506-1528 generated ash plumes that rose to an altitude of 10 km (32,800 ft) a.s.l. and drifted SE. The Aviation Color Code was raised to Red. Video images showed ash plumes rising to 6-7 km (19,700-23,000 ft) a.s.l. at 1634, to altitudes of 7-7.5 km (23,000-24,600 ft) a.s.l. at 1708 and 1722, and to altitudes of 9 km (29,500 ft) a.s.l. at 1753 and 1759. KVERT announced that the Aviation Color Code was lowered to Orange at 2038. Continuous ash emissions produced plumes that rose 3-3.5 km (9,800-11.500 ft) a.s.l. and drifted S. The lava dome continued to grow.

Geologic summary:  The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. Intermittent explosive eruptions began in the 1990s from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.

TUNGURAHUA, Ecuador 
1.467°S, 78.442°W; summit elev. 5023 m

IG reported that after a 3-month lull in activity at Tungurahua, a new eruption that began on 6 October was characterized by increased seismicity, Strombolian activity that ejected incandescent blocks, and ash plumes that produced ashfall in nearby areas. Seismicity peaked on 11 October and high-level ash plumes again produced ashfall in nearby towns. The number of explosions increased on 14 October and two small pyroclastic flows traveled a few hundred meters the next day.

Seismicity remained high during 16-22 October. Gas-and-ash plumes on 16 October rose 1 km and drifted W and N. Ashfall on 16 October accumulated more than 1 mm in Baños de Agua Santa, Runtún (6 km NNE), and Penipe (15 km SW). Strombolian activity was observed. On 17 October steam, gas, and ash plumes rose 2 km and drifted W, N, and NE. Incandescent blocks were ejected 100 m above the crater and then rolled 300 m down the flanks. Ash fell in Ulba (NNE), Juive (7 km NNW), Pelileo (8 km N), Cevallos (23 km NW), Baños (8 km N), Runtún, Bilbao (W), Palitahua (S), and Choglontus (SW). Overnight during 17-18 October incandescent blocks rolled down the flanks and explosions shook structures. During 18-21 October explosions generated ash plumes that rose 1-3 km and caused ashfall in Choglontus, Bilbao, Cusúa (8 km NW), El Manzano (8 km SW), Palitahua, Penipe (15 km SW), Chacauco (NW), Chontal, Mocha (25 km WNW), Quero (20 km NW), Cevallos, Píllate, and Ambato (31 km N). Blocks rolled down the flanks. Explosions during 21-22 October generated ash plumes that rose 3.5-4 km above the crater.

Geologic summary: The steep-sided Tungurahua stratovolcano towers more than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's capital city, and is one of Ecuador's most active volcanoes. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. The last major eruption took place from 1916 to 1918, although minor activity continued until 1925. The latest eruption began in October 1999 and prompted temporary evacuation of the town of Baños on the N side of the volcano.

VENIAMINOF, Alaska Peninsula 
56.17°N, 159.38°W; summit elev. 2507 m

Lava effusion from Veniaminof's intracaldera cone resumed on 6 October, prompting AVO to raise the Volcano Alert Level to Watch and the Aviation Color code to Orange.

On 17 October AVO noted that seismicity had decreased during the previous week and satellite observations during periods of clear weather showed no evidence of eruptive activity. The Aviation Color Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory. Seismicity remained above background levels during 17-22 October.

Geologic summary:  Massive Veniaminof volcano, one of the highest and largest volcanoes on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700 years ago. The caldera rim is up to 520 m high on the N, is deeply notched on the W by Cone Glacier, and is covered by an ice sheet on the S. Post-caldera vents are located along a NW-SE zone bisecting the caldera that extends 55 km from near the Bering Sea coast, across the caldera, and down the Pacific flank. Historical eruptions probably all originated from the westernmost and most prominent of two intra-caldera cones, which reaches an elevation of 2,156 m and rises about 300 m above the surrounding icefield. The other cone is larger, and has a summit crater or caldera that may reach 2.5 km in diameter, but is more subdued and barely rises above the glacier surface.

WHITE ISLAND, New Zealand
37.52°S, 177.18°E; summit elev. 321 m

On 21 October the GeoNet Data Centre reported that no further eruptive activity at White Island was detected after the eruption on 11 October, which ejected material over 350 m from the active vent and caused a wet surge cloud that enveloped the Main Crater. Volcanic tremor levels had decreased after the eruption and continued at variable levels. Gas flight measurements on 17 October showed that the SO2 flux was 450 tonnes per day, CO2 was 1,140 tonnes per day, and H2S was12 tonnes per day. The SO2 and H2S flux had changed very little, and CO2 had decreased from the previous measurements on 23 August. The Volcanic Alert Level was lowered to 1 and the Aviation Colour Code remained at Yellow.

Geologic summary:  The uninhabited 2 x 2.4 km White Island, one of New Zealand's most active volcanoes, is the emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The 321-m-high island consists of two overlapping stratovolcanoes; the summit crater appears to be breached to the SE because the shoreline corresponds to the level of several notches in the SE crater wall. Throughout the short historical period beginning in 1826 the volcano has had long periods of continuous hydrothermal activity and steam release, punctuated by small-to-medium eruptions. Its activity also forms a prominent part of Maori legends. The most recent eruptive episode, which began on 7 March 2000, included the largest eruption at White Island in the past 20 years on 27 July.

Ongoing activity

CHIRINKOTAN, Kuril Islands 
48.980°N, 153.480°E; summit elev. 724 m

SVERT reported that during 17-19 October a thermal anomaly from Chirinkotan was detected in satellite images along with gas-and-steam emissions drifting 30-60 km SE. Cloud cover prevented observations on the other days during 14-21 October. 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.

DUKONO, Halmahera 
1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 18-22 October ash plumes from Dukono rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted 35-150 km NE and E.

Geologic summary: Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano presenting a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.

KARYMSKY, Eastern Kamchatka (Russia) 
54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that moderate seismic activity at Karymsky was detected during 11-18 October. Satellite images showed a thermal anomaly on the volcano on 11 and 16 October, and an ash plume drifting 18 km SE on 12 October. The thermal anomalies and short ash plume possibly indicated Strombolian and weak Vulcanian activity. 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 about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-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. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.

KILAUEA, Hawaii (USA) 
19.421°N, 155.287°W; summit elev. 1222 m

During 16-22 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 5.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of a few breakouts; on 21 October geologists mapped a small breakout lava flow, with two lobes, about 3 km SE of Pu'u 'O'o.

Geologic summary: Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 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.

SAKURA-JIMA, Kyushu 
31.585°N, 130.657°E; summit elev. 1117 m

JMA reported that seven explosions from Sakura-jima's Showa Crater ejected tephra as far as 1,300 m during 15-18 October. An explosion on 15 October was followed by 3-cm-sized tephra falling in areas 3.5 km SW. Based on information from JMA, the Tokyo VAAC reported that during 16-22 October explosions generated plumes that rose to altitudes of 1.2-3.7 km (4,000-12,000 ft) a.s.l. and drifted W, SW, S, and SE. On 21 October an ash plume rose vertically to an altitude of 5.5 km (18,000 ft) a.s.l.

Geologic summary: Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. 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.

SUWANOSE-JIMA, Kyushu 
29.635°N, 129.716°E; summit elev. 799 m

According to the Tokyo VAAC, a pilot observed an ash plume from Suwanose-jima on 21 October. Based on information from JMA the VAAC noted that a plume rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted S that same day.

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

Source: GVP