New Zealand's Whakaari/White Island leads this week's global volcano report after GeoNet confirmed renewed low-level eruptive activity. Elsewhere, Stromboli experienced another lava overflow, Kīlauea entered a new pause, and several volcanoes continued sustained explosive or dome-related activity. Every measurement below is tied to its observation date.
🇳🇿 Whakaari/White Island Alert Level 3 · Orange
The biggest development of the week: GeoNet confirmed on 21 October that Whakaari/White Island was continuously and passively emitting small amounts of volcanic ash. Its Volcanic Alert Level rose from 2 to 3, and Aviation Colour Code from Yellow to Orange.
Intermittent ash was observed from 16 October. An overflight on 20 October confirmed low-energy ash-bearing steam and gas emissions and thin ash deposits around the crater. Vent temperature had risen to around 395°C. Scientists saw no evidence of an explosion. GeoNet warns that more explosive activity could occur suddenly close to the island; it reports no significant threat to mainland communities beyond possible light ash or sulphur smells under suitable winds.
Official source: GeoNet bulletins, 16–21 October
🇮🇹 Stromboli Overflow Ended · 20 Oct
INGV reported that a lava overflow down the Sciara del Fuoco was no longer being fed in its 20 October, 15:52 UTC update. Ordinary Strombolian explosive activity of varying intensity continued from both the North and Centre-South crater areas. Tremor remained at medium-to-high values, with no significant ground-deformation changes reported.
Official source: INGV, 20 October
🇺🇸 Kīlauea Advisory · Yellow
Episode 55 ended at 9:03 a.m. HST on 17 October after approximately six hours of sustained lava fountaining. HVO subsequently returned the volcano to ADVISORY/YELLOW.
In the 22 October update, summit reinflation continued, with the UWD tiltmeter recovering 10.8 microradians of inflation since episode 55, compared with about 21 microradians of deflation during the episode. Glow remained visible at the north and west vents. HVO's preliminary forecast for episode 56 is 29 October–5 November, but the unusual run-up to episode 55 adds uncertainty. It is a forecast window, not a scheduled eruption.
Official source: USGS HVO, 17 and 22 October
🇵🇭 Kanlaon Alert Level 2
PHIVOLCS' 23 October bulletin recorded five volcanic earthquakes during the previous 24-hour period, a 100-metre plume drifting northeast, and SO₂ emissions of 1,178 tonnes per day measured on 22 October. Kanlaon remains at Alert Level 2, with entry prohibited inside its 4-kilometre Permanent Danger Zone.
Official source: PHIVOLCS, 23 October
🇬🇹 Fuego Continuing Explosions
INSIVUMEH observations for 20–21 October documented up to eight explosions per hour, with eruption plumes rising as much as 1,037 metres above the vent. Incandescent rockfalls and ashfall were also reported. These are figures for the stated observation window, not a constant rate for the entire week.
Source: Smithsonian/USGS daily report citing INSIVUMEH, 21 October
🇮🇩 Merapi Level 3 · Standby
PVMBG's 21 October observations recorded three hot rockfalls reaching up to 2 kilometres and 63 seismically detected rockfalls as dome-related activity continued. The alert level remained at Level 3 (Standby) on Indonesia's four-level scale.
Source: Smithsonian/USGS daily report citing PVMBG, 21 October
🇪🇨 Reventador Orange
IG-EPN reported 45 seismically detected explosions during 20–21 October, with ash-and-gas plumes rising as much as 900 metres above the vent and incandescent rockfalls descending up to 1.2 kilometres. The alert level remained Orange.
Source: Smithsonian/USGS daily report citing IG-EPN, 21 October