Active volcanoes in the world: November 23 - 29, 2016

Active volcanoes in the world: November 23 - 29, 2016

New activity was reported for 4 volcanoes between November 23 and 29, 2016. Ongoing activity was reported for 7 volcanoes during the same period.

New activity/unrest: Chirinkotan, Kuril Islands (Russia) | Copahue, Central Chile-Argentina border | Rotorua, North Island (New Zealand) | Sabancaya, Peru.

Ongoing activity: Colima, Mexico | Dukono, Halmahera (Indonesia) | Kilauea, Hawaiian Islands (USA) | Klyuchevskoy, Central Kamchatka (Russia) | Popocatepetl, Mexico | Sheveluch, Central Kamchatka (Russia) | Suwanosejima, Ryukyu Islands (Japan).

New activity/unrest

Chirinkotan, Kuril Islands (Russia)
48.98°N, 153.48°E, Summit elev. 724 m

SVERT reported that on 29 November an ash plume rose from Chirinkotan was visible in satellite images rising to an altitude of 8.8 km (29,000 ft) a.s.l. and drifting 39 km N. The Aviation Color Code was raised to Yellow (on a four-color scale).

Geological 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.

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

Based on satellite and webcam images, the Buenos Aires VAAC reported that during 23-25 and 27-29 November diffuse steam-and-ash plumes rose from Copahue to altitudes of 3.3-5.2 km (11,000-17,000 ft) a.s.l. and drifted SW, SE, and N. The Alert Level remained at Yellow; SERNAGEOMIN recommended no entry into a restricted area within 1.5 km of the crater.

Geological 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.

Rotorua, North Island (New Zealand)
38.08°S, 176.27°E, Summit elev. 757 m

GeoNet reported a small hydrothermal eruption in Lake Rotorua on 28 November, and noted that the occurrence was not unusual. In a news article residents described a geyser that rose 20-30 m above the lake surface. A GNS scientists noted that the last significant steam eruptions in Rotorua occurred about 15 years ago.

Geological summary: The 22-km-wide Rotorua caldera is the NW-most caldera of the Taupo volcanic zone. It is the only single-event caldera in the Taupo Volcanic Zone and was formed about 220,000 years ago following eruption of the >340 cu km rhyolitic Mamaku Ignimbrite. Although caldera collapse occurred in a single event, the process was complex and involved multiple collapse blocks. The major city of Rotorua lies at the south end of the lake that fills much of the caldera. Post-collapse eruptive activity, which ceased during the Pleistocene, was restricted to lava dome extrusion without major explosive activity. The youngest activity consisted of the eruption of three lava domes less than 25,000 years ago. The major thermal areas of Takeke, Tikitere, Lake Rotokawa, and Rotorua-Whakarewarewa are located within the caldera or outside its rim, and the city of Rotorua lies within and adjacent to active geothermal fields.

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

The Technical and Scientific Committee for volcanic risk management of the Arequipa region (comprised of five groups including IGP's OVS and INGEMMET's OVI) reported 288 explosions at Sabancaya during 21-27 November. Ash plumes rose as high as 4.5 km above the crater rim and drifted 35-40 km E and SE. Sulfur dioxide emissions were as high as 3,300 tonnes/day and deformation was detected on the SE flank. During 28-29 November ash plumes rose 2 km and drifted 30 km S and SE. The Alert level remained at Yellow; the public was warned to stay at least 10 km away from the volcano.

Geological 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.

Ongoing activity

Colima, Mexico
19.514°N, 103.62°W, Summit elev. 3850 m

Based on satellite, webcam, and wind data, the Washington VAAC reported that on 26 November an ash plume from Colima rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted 75 km W. The next day a gas plume with possible ash content rose to an altitude of 5.5 (18,000 ft) a.s.l. and drifted almost 20 km N. On 28 November an ash plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted 13 km NE.

Geological summary: The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.

Dukono, Halmahera (Indonesia)
1.693°N, 127.894°E, Summit elev. 1229 m

Based on analyses of satellite imagery, information from PVMBG, and model data, the Darwin VAAC reported that during 23-29 November ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, SE, and S.

Geological 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, Summit elev. 1222 m

During 21-29 November HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 6.5 m below the Halema’uma’u floor. A section of the wall of the Overlook Vent collapsed into the lava lake on 28 November. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. Breakouts at the upper part of the lava-tube system began on 21 November, sending lava as far as 500 m S and E. These breakouts, and others inland from the ocean entry, continued to be active through 29 November.

Geological 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 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.

Klyuchevskoy, Central Kamchatka (Russia)
56.056°N, 160.642°E, Summit elev. 4754 m

KVERT reported that a daily thermal anomaly over Klyuchevskoy was visible in satellite images during 18-25 November. The Aviation Color Code remained at Yellow.

Geological 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.

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

Each day during 22-28 November CENAPRED reported 129-324 steam and gas emissions from Popocatépetl that sometimes contained ash. Volcano-tectonic events were detected during 22-24 November, and explosions occurred on 22 and 24 November (4 and 7 events, respectively). At 0945 on 25 November an explosion generated a plume that rose 5 km above the crater rim and drifted SE and NE. Seismicity decreased after the event. Ashfall was reported in areas downwind including in the municipalities of Atlixco, Tochimilco, and San Pedro Benito Juárez. During 28-29 November there were 48 detected emissions. Beginning at 0559 emissions of water vapor, gas, and ash became constant, rising as high as 1.5 km above the crater rim and drifting NE. Incandescent fragments were ejected 300-800 m form the crater, mainly onto the NE flank. Ash fell in Atlixco, Chiautzingo, Domingo Arenas, Huejotzingo, Juan C. Bonilla, San Andrés Calpan, and San Martín Texmelucan (Puebla state), and in San Miguel (Tlaxcala state). The phase of continuous emissions and ejected material ended at 1630 on 30 November. The Alert Level remained at Yellow, Phase Two.

Geological 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, Summit elev. 3283 m

KVERT reported that during 18-25 November lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions with ash plumes as high as 6 km (19,700 ft) a.s.l., and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. Satellite and video data recorded ash plumes rising to altitudes of 6-6.5 km (19,700-21,300 ft) a.s.l. and drifted 130 km SW, E, and NE on 18, 20, 22, and 24 November. The Aviation Color Code remained at Orange.

Geological 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.

Suwanosejima, Ryukyu Islands (Japan)
29.638°N, 129.714°E, Summit elev. 796 m

Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported explosions on 23, 25, and 29 November. Ash plumes on 25 and 29 November rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted S and SW. On 29 November a pilot observed an ash plume that rose to an altitude of 3 km (10,000 ft) a.s.l.

Geological 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 people live on the island.

Source: GVP


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