On October 25, 2023, Colombia’s Puracé Volcano experienced a noticeable increase in seismic activity, with earthquakes reaching a maximum magnitude of 1.0. Located between 1 and 4 km (0.6 – 2.5 miles) in depth, these quakes coincided with higher degassing levels and persistent high CO2 values.
New activity/unrest was reported for 5 from October 18 to 24, 2023. During the same period, ongoing activity was reported for 16 volcanoes.
An intense earthquake swarm started north of Grindavik and near Fagradalsfjall volcano, Iceland’s Reykjanes Peninsula early on October 25, 2023, prompting the Civil Protection Service to declare an uncertainty phase due to the seismic swarm.
On October 25, 2023, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) raised the alert status of Bulusan Volcano from Alert Level 0 to Alert Level 1 due to a period of low-level unrest that began on October 14, 2023. This includes a series of 121 volcanic earthquakes and signs of ground deformation.
Increased seismic activity has been recorded at Bogoslof volcano in Alaska since October 21, 2023, leading authorities to raise the alert level.
The Philippine Institute of Volcanology and Seismology reported a significant rise in both seismic activity and lava effusion at Mayon Volcano on October 21, 2023.
At 00:38 local time on October 21, 2023, Colombia’s Nevado del Huila volcano experienced a significant earthquake with a magnitude of 3.6 at a depth of 1 km (0.6 miles) below its Central Peak. From then until 08:00 local time, a total of 320 earthquakes were recorded, associated with rock fracturing inside the volcano.
New activity/unrest was reported for 3 volcanoes from October 11 to 17, 2023. During the same period, ongoing activity was reported for 18 volcanoes.
After several days of increased activity, a strong eruption took place at Russia’s Bezymianny volcano at around 04:30 UTC on October 18, 2023. As a result, the Kamchatka Volcanic Eruption Response Team (KVERT) increased the Aviation Color Code from Orange to Red.
Corrosive ash fallout from the massive eruption of Hunga Tonga-Hunga Ha’apai volcano last year has triggered a series of power outages on Tonga’s main island, Tongatapu, beginning September 2022. Tonga Power, the island’s electricity provider, has termed the situation a “crisis” due to the unprecedented damage to the High Voltage Aerial Bundled Cabling across the island.
