A newly reported submarine eruption in the Central Bismarck Sea led today’s activity snapshot. Explosive activity and lava effusion continued at several long-lived eruptions, including Indonesia and the Philippines. Since the previous day, Indonesia’s Lewotobi was raised to Level 3 and Alaska’s Kupreanof moved to Advisory with Aviation Yellow.
United States
Great Sitkin (Watch / Aviation ORANGE) remained in eruption. On Hawaii’s Big Island, Kilauea stayed at Advisory / Aviation Yellow with eruptive activity paused. In the Aleutians, Kupreanof was raised to Advisory / Aviation Yellow on sustained elevated seismicity and SO2 emissions; no ash was detected. Shishaldin continued in unrest at Advisory / Aviation Yellow.
Indonesia
Heightened unrest at Lewotobi prompted an alert raise to Level 3 amid elevated deep earthquakes, non-harmonic tremor, and deformation; gas emissions were observed. Eruptive activity featured frequent explosions at Semeru (ash to 1 km), Dukono (27 blasts, ash to 4.3 km), and Ibu (about 120 small explosions to 0.4 km). On Java and Sumatra, Merapi produced hot avalanches traveling up to 1.7 km, while Marapi and Lewotolok emitted low plumes with a few explosions. Several others across the arc showed ongoing Level 2 unrest without notable ash.
Philippines
At Mayon, lava effusion kept flows active to 3.8 km (Basud), 3.2 km (Bonga), and 1.6 km (Mi-isi), with minor Strombolian bursts and SO2 averaging 1,295 t/d. Kanlaon produced plumes to 600 m with crater glow and weak seismicity amid a long-term inflation trend. Taal maintained low-level unrest, while Bulusan registered 86 volcanic earthquakes and brief low plumes.
Mexico
Popocatepetl emitted ash-and-gas plumes; two small VT quakes (M1.3 and M1.1) were recorded under Yellow Phase 2.
South America
In Ecuador, Reventador and Sangay remained in eruption with alerts unchanged. Peru’s Sabancaya continued erupting at Orange.
Other
A submarine eruption at the Central Bismarck Sea produced a steam plume to 3 km and a 9 x 11 km patch of discolored water; earlier small seismic swarms preceded the activity.
Source: Smithsonian/USGS GVP Daily Volcanic Activity Report — Report date: 12 May 2026.
Activity Summary for 12 May 2026
| Volcano | Country | Activity Type | Keynotes |
|---|---|---|---|
| Central Bismarck Sea | Papua New Guinea | Eruption onset | Submarine eruption; steam plume to 3.0 km; 9×11 km discolored water. |
| Dukono | Indonesia | Eruption | 27 explosions; ash plumes to 4.3 km. |
| Great Sitkin | United States | Eruption | Eruption ongoing; Watch / Aviation ORANGE. |
| Ibu | Indonesia | Eruption | ~120 explosions; ash/gas plumes 0.2–0.4 km. |
| Kilauea | United States | Paused | Eruption paused; Advisory / Aviation YELLOW. |
| Kanlaon | Philippines | Eruption | Plumes to 0.6 km; crater glow; SO2 410 t/d. |
| Lewotobi | Indonesia | Eruption | Elevated deep quakes and tremor; deformation; gas emissions. |
| Lewotolok | Indonesia | Eruption | 6 explosions; very low plumes ~0.02 km. |
| Marapi | Indonesia | Eruption | 1 explosion; gas plumes to 0.2 km. |
| Mayon | Philippines | Eruption | Lava flows to 3.8/3.2/1.6 km; minor Strombolian bursts; SO2 1,295 t/d. |
| Merapi | Indonesia | Eruption | 3 hot avalanches to 1.7 km; 89 rockfalls; low plumes. |
| Popocatepetl | Mexico | Eruption | Ash-and-gas emissions; two small VT quakes (M1.3, M1.1). |
| Reventador | Ecuador | Eruption | Eruption ongoing; Alert Level Orange. |
| Sabancaya | Peru | Eruption | Eruption ongoing; Alert Level Orange. |
| Sangay | Ecuador | Eruption | Eruption ongoing; Alert Level 2 – Yellow. |
| Semeru | Indonesia | Eruption | 61 explosions; ash to 1.0 km; 6 rockfalls. |
| Taal | Philippines | Eruption | Ongoing unrest; Alert Level 1. |
| Awu | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Bulusan | Philippines | Unrest | Weak plumes to 0.1 km; 86 volcanic quakes; inflation. |
| Bur ni Telong | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Dempo | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Gamalama | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Karangetang | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Kerinci | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Krakatau | Indonesia | Unrest | Gas plume ~10 m at vent. |
| Kupreanof | United States | Unrest | Elevated seismicity and SO2; no ash. |
| Lokon-Empung | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Raung | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Sangeang Api | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Shishaldin | United States | Unrest | Ongoing unrest; Advisory / Aviation YELLOW. |
| Slamet | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Soputan | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Sorikmarapi | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Tambora | Indonesia | Unrest | Ongoing unrest; Alert Level 2. |
| Ijen | Indonesia | Background | Background activity; Alert Level 1 – Normal. |
| Laguna del Maule | Chile | Background | Background activity; Green Alert. |
| Tangkuban Parahu | Indonesia | Background | Background activity; Alert Level 1 – Normal. |