Volcano World

KVERT reported that eruptive activity at Bezymianny continued during 18-23 October. Large collapses on the E flanks of the lava dome that began on 17 October continued the next day. A VONA issued at 1616 on 18 October described continuing large collapses and subsequent ash plumes that rose 4.5-5 km (14,800-16,400 ft) a.s.l. and drifted 32 km NW. A large explosion at 1630 produced ash plumes that rose 10-11 km (32,800-36,100 ft) a.s.l. and drifted 50 km NNE, prompting KVERT to raise the Aviation Color Code to Red (the highest level on a four-color scale). According to the Kamchatka Volcanological Station, inclement weather clouds hindered views of the volcano but a roar was heard at about 1650 and a dark ash cloud was visible. KVERT noted that by 2030 the ash cloud had detached and was 250 m long and 70 km wide; the cloud continued to drift NNE at an altitude of 8 km (26,200 ft) a.s.l. At 2117 the Aviation Color Code was lowered to Orange. Within two days, the ash cloud drifted NE and then NW as far as 850 km. Minor ashfall was reported in Kozyrevsk, 45 km W. At 0820 on 20 October an ash plume was identified in satellite images drifting 100 km ENE at altitudes of 4-4.5 km (13,100-14,800 ft) a.s.l. At 0903 the Aviation Color Code was lowered to Yellow. Lava effusion continued; fumarolic activity and dome incandescence were visible.

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

AVO raised the Volcano Alert Level for Bogoslof to Advisory (the second level on a four-level scale) and the Aviation Color Code to Yellow (the second color on a four-color scale) on 24 October due to increased seismicity. Over 90 earthquakes were detected in the vicinity of the volcano during the previous three days. No signs of unrest had been recorded in satellite data over the past several days.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

汤加地质服务报道,eruption at Home Reef was ongoing. A total of 11 eruptive events were detected in satellite data during 16-19 October. A pilot observed an ash plume rising to 300 m at 1150 on 18 October. The Aviation Color Code remained at Yellow (the second level on a four-color scale) and mariners were advised to stay 4 km away from the island.

Source: Tonga Geological Services, Government of Tonga

KVERT报道,在Kl Strombolian喷发yuchevskoy continued during 13-20 October and fed lava flows that descended the Apakhonchichsky drainage on the SE flank. Lava descended the Kozyrevsky drainage on 17 October. A daily bright thermal anomaly was identified in satellite images and plumes of resuspended ash rose to 6 km (19,700 ft) a.s.l. and drifted 430 km E. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates and times are in UTC; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

PVMBG reported continuing inflation and increased seismicity at Slamet in a 19 October press release. An increase in the amplitude of a continuous tremor signal was recorded by the seismic network on 1 October and a period of harmonic tremor that lasted one hour and 18 minutes was recorded on 18 October. Tiltmeter and Electronic Distance Measurement data from the Cilik station located at an elevation of 1,500 m showed inflation while another station (Buncis) showed deflation; the Jurangmangu station located at a lower elevation than Cilik showed no significant deformation pattern. Inflation was recorded in tilt data at the Bambangan station (at 2,000 m elevation) during 11-18 October. Gas emissions rose 50-300 m above the summit. The Alert Level was raised to 2 (on a scale of 1-4) due to increasing activity and the public was warned to stay outside a 2 km radius.

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

JMA reported ongoing activity at Minamidake Crater (Aira Caldera?s Sakurajima volcano) during 16-23 October, with incandescence at the crater observed nightly. Sulfur dioxide emissions were extremely high, averaging 4,200 tons per day on 16 October. During the week, there were a total of 11 eruptive events and 20 explosions, with a daily average of 1-5 explosions recorded during 16-21 October. Ash plumes rose as high as 3.6 km above the crater rim and drifted E, SE, and S, and large blocks were ejected as far as 1.2 km from the crater rim. A period of inflation began at around 0600 on 21 October, but ceased following an eruptive event during 0346-0430 on 24 October; the event produced an ash plume that rose 2.3 km above the crater rim and ejected large blocks 1.2 km. 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)

In a special advisory, PHIVOLCS reported that from 0500 on 14 October to 2100 on 22 October the seismic network at Bulusan recorded a total of 87 volcanic earthquakes. Out of those, 29 were volcano-tectonic events associated with rock fracturing, located at depths of 1-8 km beneath the S and W flanks of the volcano. Gas emissions from the summit crater were at weak-to-moderate levels; sulfur dioxide emissions averaged 241 tonnes per day on 19 October, near background levels. Ground deformation data from electronic tiltmeter stations continued to record inflation at the S flank since February 2023. The Alert Level remained at 0 (the lowest level on a scale of 0-5) and PHIVOLCS reminded the public not to enter the 4-km-radius Permanent Danger Zone (PDZ).

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

KVERT reported that moderate explosive activity at Ebeko was ongoing during 13-20 October. A thermal anomaly was identified in satellite images on 14 October; weather clouds obscured views on other days. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions on 14 and 19 October generated ash plumes that rose as high as 4 km (13,100 ft) a.s.l and drifted to the E. The Aviation Color Code remained at Orange (the third 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)

An eruption at Erta Ale continued during 5-20 October based on satellite data. Four thermal anomalies were located in the N and S pit craters, aligned in a NW-SE direction, based on a 5 October image. The northernmost anomaly in the N pit crater, was relatively weak. The other three, one located at the SE rim of the N pit crater and two in the S pit crater, were brighter and likely represented spatter cones. These three anomalies were more intense in a 10 October image. An image on 15 October showed lava flows likely coming from the two cones in the S pit crater traveling SE, SSE, NE, and SW. Minor, linear anomalies to the N of the cone on the SE rim of the N pit crater likely represented lava flows. The flows had cooled by 20 October.

Source: Sentinel Hub

AVO reported that slow lava effusion at Great Sitkin was confirmed in satellite radar data on 17 October and likely continued during 18-24 October. A thick lava flow in the summit crater mainly expanded E. Seismicity was low and only a couple of earthquakes were detected during 17-19 October. Weather clouds sometimes obscured satellite and webcam views. 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)