Volcano World

According to a news article the eruption at Ioto (Iwo-jima), from a submarine vent about 1 km off the SE coast at Okinahama, continued 17 November. During an overflight of the volcano passengers observed explosions that ejected material and white steam plumes above the vent every few minutes.

Source: Daily Yomiuri News

Observatorio Vulcanolgico y Sismolgico de Popayn, Servicio Geologico Colombiano (SGC) reported that at 1929 on 16 November the seismic network recorded a signal at Purac possibly associated with an ash-and-gas emission. An emission was not confirmed in webcam images due to darkness. The Alert Level remained at Yellow (the second lowest on a four-color scale).

Source: Servicio Geolgico Colombiano (SGC)

Icelandic Meteorological Office (IMO) reported that intense seismicity and deformation at the Reykjanes volcanic system, caused by a magmatic dike intrusion with no surface eruption, was ongoing during 15-21 November. Seismicity during the week was relatively stable with 1,500-2,000 daily earthquakes; the number of events decreased during 20-21 November with only 165 recorded during 0000-1530. Earthquakes were mostly located at depths averaging 4 km. Most of the earthquakes were located near the middle of the dike, near Hagafell, 3.5 km NNE of Grindavk, and near Sundhnk, about 1 km NE of Hagafell and about 2 km ENE of Mt. Thorbjorn. Most earthquakes were less than M 2 during 15-16 November and less than M 1 during 16-17 November; the largest event during the week was an M 3 recorded on 17 November. On 16 November sulfur dioxide gas was measured from a borehole located at Svartsengi, N of Mt. Thorbjorn, and extended E to a notable depth. The presence of sulfur dioxide was another indication of the magma intrusion N of Hagafell. In addition to earthquake detected by the seismic network, new technology using the high-sensitivity fiber optic cable that runs from Svartsengi, W of Mt. Thorbjorn, to Arfadalsvk was also collecting seismic data. Deformation data was consistent with magma flowing into the dyke at depths greater than 5 km. On 17 November GPS data from instruments in and around Grindavk, near the center of the subsidence zone, indicated about 3-4 cm of subsidence per day. Analysis of COSMO-SkyMed radar interferogram data from 18-19 November showed that 30 mm of uplift was centered in the vicinity of Svartsengi, about 2 km N of Hagafell. Uplift was recorded in that same area before the 10 November magmatic intrusion, thought the rate had accelerated. The uplift aligned with the margins of the intrusion, whereas subsidence was located above the intrusion itself. The deformation and seismic data indicated that Hagafell, where the intrusion was modeled to be the widest, was the most likely location for an eruption. The Blue Lagoon geothermal pool was closed on 9 November and planned to remain closed at least until 30 November. Residents of Grindavk evacuated on 10 November, due to the uncertainty of an eruption and the onset of ground cracking and damaged infrastructure; access to the town continued to be restricted with only periodic entry allowed for residents to collect belongings. During the week ground cracks and sinkholes opened in and around Grindavk, affecting streets and buildings. Construction of earthen barriers began by 15 November to protect the Svartsengi power station, which supplies tens of thousands of people with electricity and hot water; new wells were being drilled to produce a back-up water supply. An 18 November news report indicated that most of the houses in Grindavk were undamaged, but some had been damaged along a big crack that goes through the town; a few homes were destroyed.

Sources: Almannavarnadeild rkislgreglustjra (National Commissioner of the Icelandic Police and Department of Civil Protection and Emergency Management),Icelandic Meteorological Office (IMO),Icelandic National Broadcasting Service (RUV),mbl.is

Rabaul Volcano Observatory (RVO) reported that the eruption at Ulawun continued to intensify in November and culminated in a larger event during 20-21 November. During 3-18 November white gas-and-steam plumes of variable densities rose from the summit crater. Low-level booming noises were reported on 9 November. Crater incandescence was observed nightly and fluctuated between dull and moderately bright; the most intense incandescence was observed during 10-11 November. Seismicity was at low-to-moderate levels and characterized by continuous, low-level volcanic tremors often punctuated by periods of small-to moderate discrete low-frequency volcanic earthquakes that evolved into sub-continuous volcanic tremors. Small ash emissions were observed on 19 November. Seismicity began to intensify at around 0200 on 20 November and then again at 0930. The ash emissions increased to moderate levels and eruption noises were heard between 1430-1500. The Alert Level was raised to Stage 3 (on the four-level scale). The ash plumes drifted W and NW, causing ashfall in Navo. The eruption significantly intensified during 1530-1600 and continued at high levels. According to the Darwin VAAC ash plumes rose as high as 9.1 km (30,000 ft) a.s.l. at 1600 and drifted SW. Ash plumes had risen to 15 km (50,000 ft) a.s.l. by 1630 and spread almost 65 km W by 1720. The Alert Level was raised to Stage 4. Continuous ash plumes obscured the summit area and by 1800 ashfall was reported in the Ulamona Mission area. A photo taken at 1807 showed incandescent material being ejected above the summit and a dark, dense ash plume rising from the crater. Ashfall was significant in areas to the N and NW and absent in areas to the N and E. Roaring and booming noises continued. Residents of Ubili and Ulamona Mission Station moved to Kabaya and Koasa, and Noau and Voluvolu residents moved to Bakada. Video and photos posted on social media showed tall lava fountaining at the summit and a pyroclastic flow descending the NW flank. Ash plumes continued to obscure the summit along with darkness from 2200 on 20 November to 0200 on 21 November, though the intensity of the eruption had declined. The VAAC continued to report a sustained ash plume rising to 15 km; by 0320 on 21 November ash had drifted as far as 520 km W. By 0450 the VAAC noted that ash had reached the stratosphere, rising to 18.2 km (60,000 ft) a.s.l. and drifting 75 km SE; ash at 15 km continued to drift W. Dark, dense ash emissions rose from the summit crater during 0200-1300 but were less intense. The Alert Level was lowered to Stage 3, but RVO also noted that at 0700 one of the two seismic stations had stopped working, making monitoring even more difficult. Low roaring and booming continued, and ash continued to fall mainly to the W and NW, affecting infrastructure and crops. By sunrise the view from the observation post to the summit was blanketed by ash; dense ash obscured views of the summit and flanks. RVO also noted that pyroclastic flows had likely descended the N, and possibly the SE, flanks during the early part of the eruption the day before. The VAAC reported that sustained ash plumes continued, though by 1630 they were rising to 12.2 km (40,000 ft) a.s.l. and drifting W while the ash at 18.2 km continued to drift E. During 1300-1400 ash emissions significantly decreased, allowing confirmation of a fissure vent on the SW flank at around 1,000-1,400 m elevation about 1 km SE of the 2019 fissure vent. Webcam images suggested that the lava effusion rate from the fissure was high, and that flows had descended possibly to 400 m elevation. Minor incandescent at the summit was visible as well as on the NW flank, possibly from a pyroclastic flow. Several centimeters of ash and scoria had accumulated on rooftops in areas to the N and NW. Minor ashfall was reported in Kimbe. By 2240 the VAAC stated that the ash at 18.2 km was no longer discernable in satellite images. RVO reported that during 2100 on 21 November to 0600 on 22 November the eruption was at low levels with only minor amounts of ash being emitted, though lava continued to effuse from the fissure. Summit incandescence was no longer visible by 0319. A few ash puffs were visible during 0600-0800 and then the summit was obscured by weather clouds. The Alert Level was lowered to Stage 2.

Sources: Darwin Volcanic Ash Advisory Centre (VAAC),Lekei Kilala,Rabaul Volcano Observatory (RVO),Reuters

JMA reported ongoing activity at Minamidake Crater (Aira Caldera?s Sakurajima volcano) during 13-20 November, with incandescence at the crater observed nightly. An explosion at 2053 on 13 November produced an ash plume that rose 400 m above the crater rim. Sulfur dioxide emissions were very high, averaging 3,000 tons per day on 13 November. An explosion at 0629 on 17 November generated an ash plume that rose as high as 1.1 km above the crater rim and drifted SE to SW and ejected large blocks 500-700 m from the crater. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 2 km away from both craters.

Source: Japan Meteorological Agency (JMA)

PVMBG reported that the eruption at Dukono was ongoing during 15-21 November. Seismicity was high during most of the week but began to decline on 19 November, though eruptive activity remained elevated. Daily dense white-and-gray or gray-to-black ash plumes rose as high as 1.2 km above the summit during 15-16 November, up to 2.6 km on 17 November, 3 km on 18 November, 2.6 km on 19 November, and 2.3 km on 20 November. The plumes mainly drifted E and NE each day, though on 17 November they also drifted SE. Thumping noises were reported on 17 November. The Alert Level remained at Level 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

KVERT reported that moderate explosive activity at Ebeko was ongoing during 10-16 November. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions on 13 November generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l and drifted E. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are UTC; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

INGV reported that Strombolian activity resumed at Etna?s SE Crater (SEC) on 22 October and became more continuous and intense through early November. An increase in the frequency of explosions occurred on 4 November, with one occurring about every three minutes. A small new cone formed on the NW flank, near the saddle, that effused lava for a few hours and produced two lava flows that traveled a maximum of 10 m. Strombolian activity at SEC was recorded during 10-12 November, and at 1000 on the 12th a small lava flow was produced. The activity intensified during the afternoon and lava fountaining commenced at around 1730, though weather clouds hindered views. Two main explosive vents were discernable and produced an ash plume that rose almost 1.2 km above the summit and drifted ESE. Ash and lapilli fell in areas from Milo to Zafferana and from Torre Archirafi to Pozzillo. Starting at around 2040 several pyroclastic flows descended the SSE flank and reached the W part of the Valle del Bove. Eruptive activity decreased at around 2100. Minor Strombolian activity continued, and several lava flows traveled S, SE, SSW, and SW.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

AVO reported that slow lava effusion continued at Great Sitkin during 15-21 November, confirmed at least through 16 November by a radar image. The thick flow in the summit crater mainly expanded E. Seismicity was low. Steam emissions were visible in satellite and webcam images during 18-19 November. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

PVMBG reported that Ibu continued to erupt during 15-21 November. White-and-gray ash emissions that were sometimes dense rose 200-1,000 m above the summit and drifted E, SE, and S during 15-17 and 21 November. The Alert Level remained at a 2 (the second highest level on a four-level scale), with the public advised to stay outside of the 2 km hazard zone and 3.5 km away from the N area of the active crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)