The VSI reported that during 23-29 January no explosive activity occurred, but a plume of white ash rose 100-500 m above the crater. The volcano remained at Alert Level 3 (on a scale of 1-4).

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

The VSI reported that activity remained normal during 23-29 January. There were no major changes since the previous week when the Alert Level was raised from level 1 to 2 on 19 January after several monitored parameters changed at the volcano. Kelut remained at Alert Level 2 (on a scale of 1-4).

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

The VSI reported that volcanic activity increased in comparison to the previous week. Explosions began occurring at 1920 on 28 January and produced glowing ejecta (volcanic bombs) that fell on the N slope of the volcano. The height of the ash cloud that was produced by the eruption could not be measured due to unfavorable weather conditions. A strong sulfurous smell was detected from Kakaskasen observatory. On the morning of 29 January an ash plume rose continuously up to 300 m above the crater. The Alert Level at the volcano was raised during the report period from level 2 to 3 (on a scale of 1-4).

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

PHIVOLCS reported that numerous shallow earthquakes, high SO₂ emission rates, and sustained inflation during the week reflected the active state of the growing summit lava dome. They reported that during the week up to 46 volcanic earthquakes were recorded per day, the SO₂ emission rate increased from 2,600 metric tons per day (t/d) on 1 February to 5,330 t/d on 5 February, and electronic tiltmeters on the N flank of the cone continued to detect inflation at the volcano's edifice. Incandescence was visible periodically at the summit. On 1 February, officials recommended that residents of the five towns within the 6-km-radius Permanent Danger Zone evacuate the area. In addition, PHIVOLCS warned residents just outside of the Permanent Danger Zone to be alert for potential hazardous volcanic flows, which may be channeled by rivers and gullies that radiate from the summit. Mayon remained at Alert Level 3 (on a scale of 0-5).

Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Reuters, Agence France-Presse (AFP)

The VSI reported that activity continued to increase during 23 January-1 February. At 0000 on 27 January an eruption produced continuous pyroclastic flows and molten lava avalanches that lasted as long as 2 hours. The eruption also produced a thick ash plume that rose 2 km above the volcano's summit and was accompanied by a strong sulfurous smell. On 28 January, "lava dome 2001" partially collapsed, resulting in pyroclastic flows and molten lava avalanches that occurred at 2-5 minute intervals. The avalanche and pyroclastic-flow material traveled down the Sat and Bebeng rivers to the SW, and Senowo River to the W. The maximum runout distance of 4.5 km occurred in the Sat River. Ash fell in 5 districts within a 15-20 km radius around the volcano; Dukun, Srumbung, Salam, Ngluwar, and Muntilan. On 31 January, pyroclastic flows continuously entered the Sat River, and to a lesser extent the Senowo and Bebeng rivers. The maximum runout distance was ~3.5 km. Again, ash fell on the towns within a ~15 km radius around the volcano. Visual observations and photographic analysis revealed that the dome became higher and larger than it was during the previous report period, and that there was a new active point at the summit that may have been a fumarole or a hot spot. The volcano remained at Alert Level 3 (on a scale of 1-4).

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Agence France-Presse (AFP), Associated Press

According to a preliminary report from USAID/OFDA, Nyamuragira began erupting at 0032 on 6 February. Observations made during a flight over the volcano revealed that there were active lava flows. The lava appeared to be flowing from two fissures; one to the W towards the town of Kitchanga, and another to the S in the direction of the town of Mugunga (Sake) and Nyiragongo volcano. Smoke was observed near the volcano and the sound of thunder was heard. Cloudy conditions prevented clear observations of the volcano.

Source: US Agency for International Development / Bureau for Humanitarian Assistance

The IGNS wrote, "On Friday 26 January at about 1530 to 1540, a muddy hot pool (Spring 721) erupted violently in the largest hydrothermal eruption in Kuirau Park since 1966. Blocks of rock debris and mud were blasted to a height of about 100 m. Blocks up to a meter in diameter were blown over 50 m from the vent, with fragments up to 10 cm landing over 100 m away. The steam cloud from the eruption was visible several kilometers away." The eruption deposited debris 120 m to the E of the vent and ~30 m to the W. The original hot pool was about 3 meters in diameter; the newly formed crater was about 10-12 m in diameter.

Sources: GeoNet, GeoNet

According to the Italy's Volcanoes website, since 20 January lava has continuously issued at a low but persistent rate from a vent on the NNE flank of the Southeast Crater. The lava formed a small field of overlapping and adjacent flows that extend a few hundred meters. At Bocca Nuova Crater Strombolian activity increased, with ejecta being thrown above the crater rim.

Source: Italy's Volcanoes

The IG reported on 31 January that seismicity and volcanic activity remained at moderate levels. Continuous dome growth persisted at dome 9 and small morphologic changes were observed at the dome the previous week.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

The VSI reported that during 23-29 January explosive activity continued, with explosions on both 25 and 28 January. At 2227 on 25 January a minor explosion produced a thick ash plume that rose 700 m above the volcano, blew to the W, and dropped ash over the sea. The explosion also produced a lava avalanche that traveled ~1,250 m down the Kelitu River. The second explosion during the report period occurred at 2109 on 28 January and produced a Strombolian-type eruption with glowing ejecta that reached up to 300 m above the crater. In addition, a black ash-filled plume rose to ~1 km above the volcano. The explosion opened a new crater in the lava dome and produced a lava avalanche that traveled ~1.5 km down the W slope of the volcano. The volcano remained at Alert Level 2 (on a scale of 1-4).

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

The HVO reported that lava had not entered the sea since 29 January. Surface lava flow activity occurred primarily on the E branch of the flow on the Pūlama pali, with some breakouts occurring along the trace of the W branch of the flow. Overall, volcanic tremor near Puʻu ʻŌʻō and in Kīlauea's caldera was at low-to-moderate levels. Tiltmeters in the summit area and along the E rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

The Washington VAAC reported that during 1530 to 1545 on 30 January a moderate ash emission was visible on the CENAPRED camera; it rose to ~7 km a.s.l. and blew to the NNE. At 1345 on 1 February a small eruption was visible on GOES-8 imagery. The narrow plume of ash rose to ~6.7 km and blew to the NNE. The volcano remained at Alert Level Yellow Phase III, with a restricted area of 12-km-radius.

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)

The KVERT reported that at 1802 and 1820 on 29 January, shallow earthquakes were registered beneath the volcano that were accompanied by short-lived explosions. The ash cloud produced from the first explosion reached ~2.5 km above the volcano, while the second eruption's ash cloud could not be observed. During 26-31 January a gas-and-steam plume rose 50-800 m above the volcano, and on 1 February a gas-and-steam plume rose 2 km above the volcano. The Concern Color Code remained at Yellow.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

The MVO reported that activity at the Soufrière Hills Volcano was lower than during the previous week, although the lava dome continued to grow. The level of seismicity was also generally lower. During the morning of 29 January a very low-energy swarm of 20 volcano-tectonic earthquakes occurred to the NE of the volcano. During the week, brief observations revealed that volcanic activity remained concentrated on the SE side of the dome. On 1 February, a small pyroclastic flow was observed in the White River Valley. It traveled ~1 km to the SE and produced a small ash cloud that rose to a maximum height of ~1.5 km a.s.l.

Source: Montserrat Volcano Observatory (MVO)