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 2300 UTC every Wednesday, these notices are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of eruptions during the week, but rather a summary of activity that meet selected criteria. Carefully reviewed, detailed reports are published in the Bulletin of the Global Volcanism Network.

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that a thermal anomaly over Bezymianny was identified in satellite images during 6-13 February. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are reported in UTC; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Sezione di Catania - Osservatorio Etneo (INGV) reported that the new eruption that began at Etna on 6 February continued during 10-16 February. Activity observed through webcams and during daily field inspections was characterized by the effusion of a lava flow from a fissure and explosive activity at the summit. The lava flow from the fissure that opened at the base of Bocca Nuova Crater on 8 February continued to effuse lava. The lava flow advanced down the SW flank, descending to 2,150 elevation by 11 February and 1,960 elevation by 13 February. The distal end of the flow was 6-8 m thick. Photogrammetric data collected by drones on 14 and 16 February, combined with satellite data, showed that the lava flow advanced 380 m during that 48-hour period. The total flow length was 4.2 km and covered an estimated area of 0.3 square kilometers (300,000 square meters). There were reports of phreatic explosions from the interaction with lava and snow that ejected lava fragments a few hundred meters, particularly on 12 February. Explosive activity at SE Crater originated from at least two vents based on webcam views and a 12 February field inspection. During the field inspection weak explosive activity originated from a vent located between SE Crater and Bocca Nuova Crater. Minor ash emissions rose from SE Crater and quickly dissipated downwind, depositing ash near the summit. Ash emissions intensified on 12, 14, and 16 February; the Aviation Color Code was raised to Red (the highest level on a four-color scale) on 12 February then back to Orange on 13 February, to Red on 14 February and back to Orange that same day, again to Red on 16 February, and back to orange on 18 February. Although weather conditions sometimes obscured views, the ash emissions rose no higher than an estimated maximum altitude of 5.5 km a.s.l. (about 2.1 km above the summit). According to a news report flights in and out of the Catania-Fontanarossa Airport were disrupted during 12-17 February.

Sources: Euronews,Sezione di Catania - Osservatorio Etneo (INGV)

The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea?s Kaluapele summit caldera, from vents along the SW margin of Halema?uma?u Crater, continued at variable levels during 11-18 February. A period of lava fountaining and effusion of lava onto the crater floor began at 1016 on 11 February and lasted more than 22 hours. Lava fountains rose as high as 100 m at the N vent and were bifurcated at the S vent, rising as high as 30 m. Both effusion rates and lava-fountain heights decreased by the morning of 12 February. Lava fountaining stopped at the N vent at 0830 and within a few minutes fountaining at the S vent was less vigorous. A small amount of lava continued to effuse from the S vent then completely ceased at 0843. Lava flows had traveled about 1 km across the crater floor, covering 50-60% of the surface. Overnight during 12-13 February several lava flows slowly moved on the crater floor. During 12-18 February areas of incandescence and gas emissions at the N vent and incandescence from cooling lava flows on the crater floor were visible. Incandescence and gas emissions were also visible at the S vent during 15-18 February. 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 Hawaiian Volcano Observatory (HVO)

On 6 February the Servicio Nacional de Geología y Minería (SERNAGEOMIN) issued a special report noting increased emissions at Láscar. A whitish-colored gas plume observed in webcam views rose almost 2 km above the summit. Sulfur dioxide emissions detected in satellite data were 188 tons per day which was characterized as atypical during the previous year. A thermal anomaly in the crater was identified in satellite data suggesting an increase in temperature within the crater. Seismicity did not clearly indicate variations that may be related to unrest, though two long-period earthquakes were recorded on 7 and 9 February. Sulfur dioxide emissions increased to 752 tons on 11 February. On 12 February the Alert Level was raised to Yellow (the second lowest level on a four-color scale) and the public was warned to stay at least 1 km away from the crater.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki during 12-18 February. A sudden increase in the number of volcanic earthquakes was detected at 2200 on 11 February and the seismicity remained at high levels. At 0300 on 12 February the exclusion zone was expanded to a radius of 5 km from the center of Laki-laki and 6 km in a semicircle counterclockwise from the NE to the SW. The Alert Level was raised to 4 (on a scale of 1-4) at 0300 on 13 February and the exclusion zone was again expanded to 6 km from the center of Laki-laki and 7 km in a semicircle counterclockwise from the NE to the SW. PVMBG noted that during 3 January-13 February the seismic network also detected increases in harmonic tremor, low-frequency earthquakes, and shallow volcanic earthquakes. Observable activity also increased and fumarolic plumes rose from cracks on the upper NW flank, though weather conditions often obscured views. Crater incandescence was visible, but often faint. BNPB recommended that residents evacuate from the six villages within the expanded exclusion zone including Nobo (5 km NE), Dulipali (6 km NNW), and Hokeng Jaya (3 km WNW). During 13-17 February dense white plumes rose 400-600 m above the summit. Seismicity fluctuated, but notably deep volcanic earthquakes were recorded during 16-17 February while shallow volcanic earthquakes were not. At 0558, 1622, and 2343 on 17 February dense gray ash plumes rose 400-900 m above the summit and drifted N and NE.

Sources: Badan Nacional Penanggulangan Bencana (BNPB) ,Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that at 0200 on 16 February an eruptive event at Lewotolok generated a gray ash plume that rose around 200 m above the summit and drifted E. At 0922 on 16 February and at 0012 on 17 February dense white-and-gray ash plumes rose 100-200 m and drifted E and SE, respectively. Incandescence at the summit was visible in a webcam image from 0013 on 17 February. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the vent and 2.5 km away on the S, SE, and W flanks.

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

The Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported that eruptive activity at Poás was recorded during 11-18 February. The lake water level had dropped about 0.3 m in a week and convection cells over underwater fumarolic vents persisted; convecting water over Boca C vent was noted during 11-12 February. Sulfur dioxide gas flux significantly increased to 445 +/- 504 tons per day (t/d) on 13 February and was higher than the average of 267 +/- 97 t/d detected during the previous week. Frequent (every minute) phreatic explosions at Boca C were recorded during 15-17 February based on seismic and acoustic data. Material was ejected above the lake?s surface as high as 200 m. Sulfur dioxide emissions had decreased by 16 February. The frequency of phreatic explosions decreased during 17-18 February, though events were characterized as both intense and low magnitude, with ejected material rising less than 200 m.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Unrest at Ahyi Seamount continued during 7-13 February. A satellite image on 8 February showed a plume of discolored water in the vicinity of the seamount, indicating possible submarine activity. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).

Source: US Geological Survey

The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera?s Sakurajima volcano) during 10-17 February. Nightly crater incandescence was visible in webcam images. On 10 February sulfur dioxide emissions were high, averaging 2,200 tons per day. Six eruptive events, recorded during 11 and 15-16 February, produced ash plumes that rose 1-1.2 km above the summit and drifted SE, E, and NE. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 1 km away from both craters.

Source: Japan Meteorological Agency (JMA)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Dukono was ongoing during 12-18 February. Daily white-and-gray ash plumes rose 100-1,500 m above the crater rim and drifted in multiple directions. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater.

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

The Instituto Geofísico del Perú (IGP) reported that three lahars carrying blocks traveled down El Misti?s flanks on 15 February. The first descended the Matagente drainage on the NW flank at 1637, the second descended the El Pato drainage on the SW flank at 1750, and the third descended the Huarangal-Los Incas drainage on the SW flank at 1820. The public was warned to stay away from drainages and roads on the SW flank. The Alert Level remained at Green (the lowest level on a four-color scale).

Source: Instituto Geofísico del Perú (IGP)

The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick lava flow in Great Sitkin?s summit crater, confirmed by a 10 February radar image. The lava flow advanced along the NNE margin. Small daily earthquakes were detected by the seismic network during 10-18 February. Weakly elevated surface temperatures were identified in satellite data during 15-18 February. Cloudy weather obscured satellite and webcam images during most of the week. 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)