Global volcanic monitoring networks tracked persistent ash emissions, seismic swarms, and lava flows across multiple continents as observatories issued fresh advisories for October 21, 2026.
Seismic Unrest Persists Below Mount Etna’s Flanks
An earthquake measuring 3.9 on the Richter scale struck beneath Mount Etna’s eastern flank at 08:49 local time at a shallow depth of only 4 kilometers, Volcano Discovery reported. Residents felt the tremor in nearby towns including Zafferana, Santa Venerina, and Milo. The volcano observatory in Catania noted that while the event was tectonic in origin, such shallow tremors can trigger underground magma movements.
This ground motion followed a busier seismic period three days earlier on October 18, when an earthquake swarm generated 20 tremors of magnitude 1.0 or greater beneath the western flank. That swarm included a magnitude 3.3 quake at 04:20 UTC centered approximately 600 meters southwest of Monte Minardo at a depth of 6.3 kilometers. Quieter conditions followed on October 19 and 20, registering only minor events near Monte Fontane and Maletto. Monitored parameters including ground deformation, degassing rates, and thermal radiation showed no significant variations, indicating that a new eruption remains unconfirmed.
Whakaari White Island Raises Alert Levels After Vent Temperature Surges
New Zealand’s Whakaari, also known as White Island, transitioned from intermittent bursts to continuous passive emission of steam, gas, and minor amounts of volcanic ash following an observation flight on October 20, 2026. The Wellington Volcanic Ash Advisory Center reported ash plumes rising to an estimated 5,000 feet, or flight level 050, moving south at 5 knots.
Over the preceding week, the active vent temperature increased sharply from approximately 100°C to 395°C, accompanied by daily sulfur dioxide emissions detected via satellite. In response, authorities raised the Volcanic Alert Level to Level 3 and the Aviation Colour Code to Orange. Minor ashfall remains likely on and near the island, though mainland impacts are not expected under current conditions.
Ash Advisories Track Global Explosive Activity
Volcanic Ash Advisory Centers across the globe issued continuous bulletins for active summits producing sustained plumes and persistent Strombolian activity:
- Sakurajima: Tokyo VAAC reported an explosion at 12:20 UTC on October 21, pushing ash over flight level 050 towards the southeast.
- Taal: An eruption was reported at 15:40 UTC on October 21, though satellite data identified no distinct ash cloud at the time.
- Ibu and Dukono: Darwin VAAC monitored ongoing explosive activity in Halmahera, Indonesia, with ash plumes reaching 6,000 feet and 7,000 feet respectively.
- Krakatau: Explosive activity in the Sunda Strait generated an ash plume rising to 8,000 feet on October 21.
- Sangay and Reventador: Washington VAAC tracked ongoing explosions in Ecuador, with Sangay’s ash plume reaching flight level 230 and Reventador reaching flight level 160.
Frequently Asked Questions About Current Volcanic Activity
What caused the recent seismic activity at Mount Etna?
The 3.9 magnitude earthquake on October 21 was tectonic in nature, originating at a shallow depth of 4 kilometers below the eastern flank. While it was felt in nearby towns, Catania observatory scientists noted it was part of an ongoing seismic swarm that included 20 smaller quakes days prior.
Why was the alert level raised for Whakaari White Island?
New Zealand authorities raised the alert to Level 3 after an observation flight confirmed continuous passive ash emission and a dramatic vent temperature surge from 100°C up to 395°C over a single week.
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