Volcano World

KVERT reported that a thermal anomaly over Alaid was identified in satellite images during 15-22 September. On 18 September an ash plume drifted 50 km E. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

The Tonga Geological Services reported that the new island at Home Reef that emerged from the ocean on 10 September continued to grow through 27 September. The eruption continued at variable intensities, mainly producing daily plumes of gas and steam that rose no higher than 2 km above sea level. During 0040-0250 on 25 September steam-and-ash plumes rose 2-4 km a.s.l. and drifted 30 km W, S, and SE. At 0030 on 27 September an ash plume rose 6-8 km a.s.l. and drifted 25 km SSE. The island was surrounded by plumes of discolored water. Mariners were advised to stay 4 km away from the volcano.

Source: Tonga Geological Services, Government of Tonga

OVPF reported that the eruption at Piton de la Fournaise that began on 19 September, E of Piton Kala Pl, was ongoing during 21-27 September. Gas plumes drifted SW, WSW, W, NNW, and were detected as far as 200 km from the vent in a 27 September satellite image. The active cone on the low end of the fissure ejected lava to low heights above the cone?s rim. Lava flows from the base of the cone formed two main flows that traveled SE and ESE. Lava flowed through sections of tubes mainly located along the first kilometer of both flows. Average daily lava-flow rate estimates varied from 1 to 8 meters per second based on satellite data. The SE flow front had advanced to the Chteau Fort crater area, reaching 2,000 m elevation on 24 September, though that flow had stopped advancing by 26 September. The eruption was confined to the caldera, so the Alert Level remained at 2-1 (?2? is the highest level of a 3-level scale and ?-1? denotes the lowest of three sub-levels).

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

On 28 September GeoNet reported that seismic unrest and deformation at Taupo continued during the previous week. About 750 earthquakes have been located at depths of 4-13 km beneath the lake since unrest began in May. During the past week the locations were concentrated beneath the E part of the lake and occurred at a slightly lower rate than the week before. An area of deformation at Horomatangi Reef had been rising at a rate of 60 mm (plus or minus 20 mm) per year since May. The data suggested that the seismicity and deformation was caused by the movement of magma and hydrothermal fluids. GeoNet noted that unrest at calderas was common and may continue for months or years without resulting in an eruption; more significant unrest would be indicated by additional indicators of activity and substantial impacts on the local area. The Volcanic Alert Level remained at 1 (the second lowest level on a six-level scale) reflecting ?minor volcanic unrest? characterized by ongoing seismicity and inflation.

Source: GeoNet

JMA reported that six eruptive events and three explosions at Minamidake Crater (at Aira Caldera?s Sakurajima volcano) were recorded during 19-26 September. Volcanic plumes rose as high as 2.4 km above the crater rim and large blocks were ejected as far as 700 m from the vent. Incandescence at the crater was visible nightly. Sulfur dioxide emissions were somewhat high at 1,900 tons per day on 22 September. Nighttime incandescence at the crater was visible during 2-16 September. A notable eruptive event at 1335 on 23 September generated an ash plume that rose 1.7 km above the crater rim and also drifted down-flank to the SE until 1600. A large amount of ashfall was deposited on the SE flank. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.

Source: Japan Meteorological Agency (JMA)

KVERT reported that moderate activity at Ebeko was ongoing. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 3.5 km (11,500 ft) a.s.l. and drifted E. A thermal anomaly over the volcano was identified in satellite images on 18 September. Ash fell in Severo-Kurilsk during 20-22 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

AVO reported that slow lava effusion at Great Sitkin likely continued during 20-27 September. Elevated surface temperatures were identified during 20-21 September; weather clouds often prevented webcam and satellite views during the rest of the week. A data outage that affected the local seismic network was resolved by 23 September. Seismicity was low during 24-25 September. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 16-18 and 20-21 September. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea?s Halema`uma`u Crater during 20-27 September, entering the lava lake and flowing onto the crater floor. The continuously active part of the lake dropped 10 m, regained 3 m during 19-22 September, and then was unchanged the rest of the week. Breakouts of lava occurred at the W and N margins of the lake during most of the week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Strong winds re-suspended ash from the E flank of Klyuchevskoy and created plumes that were visible in satellite images drifting 460 km SE during 21-22 September. KVERT raised the Aviation Color Code to Orange on 21 September but lowered it back to Green on 24 September. Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)