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 Thursday, 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 Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported ongoing eruptive activity at Lewotolok during 29 January-3 February. White plumes were visible on 30 January and 1 February rising as high as 50 m above the summit and drifting E. On 31 January white-and-gray ash plumes rose 100 m above the crater rim and drifted E. Emissions either did not occur or were not visually observed on the other days. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit.

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

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that the eruption at Mayon continued during 28 January-4 February, characterized by effusion and collapses at the summit dome, pyroclastic density currents (PDCs), rockfalls, ash plumes, avalanches of incandescent material, and lava flows. Episodic and minor Strombolian activity was visible on 28 January. Moderate emissions rose as high as 1 km above the summit and drifted in various directions during 28-30 January and on 4 February; weather clouds obscured views on the other days. The seismic network recorded 284-389 daily rockfall events and 26-68 daily PDCs. The number of volcanic earthquakes recorded was variable: 119 on 28 February, 21 on 29 February, and 0-9 daily the rest of the week. Sulfur dioxide emissions increased each day, averaging 1,275 tonnes per day (t/d) on 28 January and rising to 5,297 t/d by 3 February. Sulfur dioxide emissions peaked at 6,569 t/d on 4 February, the highest average recorded in the past 15 years. According to a news report ashfall was reported on 2 February in at least five villages including Quirangay, Sua, Tumpa, Libod and Anoling. Ash fell with rain causing reduced road visibility and affecting local farmlands. By 1800 on 4 February a total of 4,058 people (1,115 families) were staying in 13 evacuation shelters, and an additional 53 people (17 families) were staying with friends or relatives, according to the Disaster Response Operations Monitoring and Information Center (DROMIC). The Alert Level remained at 3 (on a 0-5 scale) and residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ). PHIVOLCS recommended that civil aviation authorities advise pilots to avoid flying close to the summit.

Sources: Disaster Response Operations Monitoring and Information Center (DROMIC),Inquirer.net,Philippine Institute of Volcanology and Seismology (PHIVOLCS)

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported continuing eruptive activity at Sheveluch?s ?300 years of RAS? dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 28 January-4 February. A daily thermal anomaly was identified in satellite images. Tall ash plumes were generated on a few days during the week. An explosive period that began at 0030 on 29 January produced ash plumes that rose 4 km (13,100 ft) a.s.l. and drifted 35 WSW by 0050 based on satellite images. At 2110 on 31 January an ash plume rose 6 km (19,700 ft) a.s.l. and drifted 70 km WNW. Explosions generated an ash plume rose 11 km (36,100 ft) a.s.l. at 0130 on 2 February; the 24 x 34 km plume was identified in a satellite image drifting 50 km NNE. At 0220 the Aviation Color Code was raised to Red (the highest level on a four-color scale). Explosions a few hours later produced ash plumes that rose 7.5 km (24,600 ft) a.s.l. by 0405 and drifted 36 km NE. The previous ash cloud was 135 x 60 km and was 228 km NW. At 0614 the Aviation Color Code was lowered to Orange. An explosion on 3 February generated an ash cloud that was 25 x 15 km, rose to 11.5 km (37,700 ft) a.s.l. by 0251, and drifted 80 km NW. At 0345 the Aviation Color Code was raised to Red, but then lowered back to Orange at 0552. According to the Kamchatka Volcanological Station (Volkstat) the NW part of the lava dome was active and glowing ash plumes with frequent lightning strikes had recently been observed at night. Dates are based on UTC; specific events are in local time where noted.

Sources: Kamchatka Volcanological Station,Kamchatkan Volcanic Eruption Response Team (KVERT)

The Alaska Volcano Observatory (AVO) reported that on 29 January plumes of unconsolidated ash in the vicinity of Okmok were visible in satellite images possibly rising as high as 900 m (3,000 ft) a.s.l. and drifting S. According to the Anchorage Volcanic Ash Advisory Center (VAAC) plumes of unconsolidated ash were identified the next day as well, drifting SSW at the same altitude. The Volcano Alert Level remained at Normal (the lowest level on a four-level scale) and the Aviation Color Code remained at Green (the lowest level on a four-color scale).

Sources: Anchorage Volcanic Ash Advisory Center (VAAC) ,US Geological Survey Alaska Volcano Observatory (AVO)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 29 January-1 February. White-and-gray gas-and-ash plumes rose 50-400 m above the summit and drifted in multiple directions on most days; white plumes rose 200-400 m above the crater rim and drifted E on 30 January. 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 Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin?s summit crater during 28 January-4 February. Seismic activity was low, with occasional small earthquakes and rockfalls detected by the seismic network. Weather clouds often obscured satellite and webcam views. Slightly warm, snow-free areas of the active lava dome were observed in clear satellite images during 28-29 January. 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)

Satellite images of Heard Island?s Big Ben volcano showed a temperature anomaly at the summit and on the W and SW flanks on 27 and 29 January and 1 February, suggestive of active lava flows. A small anomaly on the upper NE flank in the 27 February followed by a darker area in subsequent images suggested an active then cooling lava flow.

Source: Copernicus

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity at Ibu continued during 29 January-3 February with daily eruptive events recorded. Daily white-to-gray or gray ash plumes rose 300-800 m above the summit and drifted in multiple directions. Incandescence at the summit was visible in a few nighttime webcam images. The Alert Level remained at 2 (the second lowest level on a four-level scale) and the public was advised to stay 2 km away from the active crater and 3.5 km away from the N crater wall opening.

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

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 28 January-4 February. The seismic network recorded 0-5 daily volcanic earthquakes. Gas-and-steam emissions rose as high as 1.5 km above the crater rim and drifted mainly W, SW, and S and occasionally NE. Sulfur dioxide emissions ranged from 688 to 2,092 tonnes per day. According to the Tokyo Volcanic Ash Advisory Center (VAAC) an ash plume rose to 3 km (10,000 ft) a.s.l. (or about 600 m above the summit) and drifted SW at 1344 on 4 February, based on satellite images. PHIVOLCS noted that the ash emissions lasted for six minutes. The Alert Level remained at 2 (on a scale of 0-5); the public was warned to stay out of the 4-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit.

Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS) ,Tokyo Volcanic Ash Advisory Center (VAAC)

The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea?s Kaluapele summit caldera, characterized by episodic fountaining, incandescence, and intermittent spatter from craters along the SW margin of Halema?uma?u Crater, continued at variable levels during 29 January-4 February. Incandescence from both the N and S vents was intermittent during the week, though stronger at the S vent. Flames at the N vent were visible nightly beginning on 30 January. Pulses of increased tremor beneath the summit occurred several times per hour during the second half of the week. These pulses correlated with periods of increased brightness at the S vent, suggesting that gas pistoning was probably occurring within that conduit. 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)

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that lava flows at Krasheninnikov continued to descend the ENE flanks of the Northern Cone and gas-and-steam emissions continued to rise from the cone. A large bright thermal anomaly continued to be identified in satellite images, though the temperature of the anomaly compared to the background temperatures surrounding the active areas began to decrease on 18 January. At 2236 on 29 January the Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale). Dates and times are provided in Coordinated Universal Time (UTC); specific events are indicated in local time where specified.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

The eruption at Nyamulagira continued in January, with observations based on satellite images. Incandescence on the floor of the summit caldera and from active lava flows on the WNW and NW flanks were visible in a clear 21 January satellite image and a mostly cloudy image from 31 January. The distal end of the farthest lava flow was about 8 km from the crater rim.

Source: Copernicus