Caldera โข Aleutians, USA
Unlikely in any given year
Okmok erupts infrequently, so the chance in any single year is low. Our model estimates a 6.7% chance of an eruption in the next 12 months โ about one eruption every ~14 years on average. Its most recent known eruption was 2008.
Statistical estimate, not a prediction โ medium confidence. Always follow official volcano observatory advisories. How this is calculated โ
6.7%
1-year
0.6%
30-day
~14y
recurrence
53.428ยฐ, -168.131ยฐ ยท USA ยท 12 nearby earthquakes
6.7%
1-year probability
0.6%
30-day
~14y
Avg. recurrence
moderate
Risk level
~1 eruption every 14 yr โ the GVP eruption frequency blended toward a caldera prior by how complete the record is.
19 dated eruptions over ~8318 yr โ a well-documented record the rate can rely on.
Most eruptions ~VEI 3; capable of large (VEI โฅ 4) events โ largest recorded VEI 6. ~1.4% chance of a VEI โฅ 4 event this year.
A recently active volcano gets a higher near-term rate; a long-dormant one is tempered.
No live PHIVOLCS/seismic feed for this volcano, so short-term precursors and alert levels are not applied.
Confidence: A monitoring network and a multi-eruption history constrain the estimate, but with meaningful uncertainty.
How this is calculated โPoisson estimate from the GVP eruption frequency, blended toward a volcano-type prior by how complete the record is and adjusted for recency โ 1-year range 4.8โ9.2% (confidence medium; no live seismic feed for this volcano). Philippine volcanoes additionally use live PHIVOLCS alert levels and seismicity โ see the Risk Analysis dashboard.
severe ยท very high explosivity
Largest recorded: VEI 6
Most eruptions ~VEI 3; capable of large (VEI โฅ 4) events โ largest recorded VEI 6.
19 dated eruptions over ~8318 yr โ a well-documented record the rate can rely on.
Size from the volcano's VEI record combined with the global eruption sizeโfrequency relation; the record grade reflects how complete its eruptive history is โ sparse records lean on a volcano-type prior with wider uncertainty. How this is calculated โ
1,073m
Elevation
2008
Last Eruption
VEI 4
Explosivity Index
Caldera
Type
54 km ENE of Nikolski, Alaska
66.4km deep โข 31km away
83 km ENE of Nikolski, Alaska
67.6km deep โข 40km away
24 km NE of Nikolski, Alaska
75.0km deep โข 49km away
35 km E of Nikolski, Alaska
48.1km deep โข 56km away
70 km E of Nikolski, Alaska
43.3km deep โข 58km away
59 km WSW of Unalaska, Alaska
92.3km deep โข 58km away
37 km E of Nikolski, Alaska
48.0km deep โข 60km away
80 km E of Nikolski, Alaska
43.0km deep โข 63km away
86 km SSW of Unalaska, Alaska
59.0km deep โข 67km away
77 km SSW of Unalaska, Alaska
55.6km deep โข 70km away
53 km ESE of Nikolski, Alaska
26.2km deep โข 72km away
92 km E of Nikolski, Alaska
33.1km deep โข 73km away
Coordinates
53.4285ยฐN, -168.1305ยฐE
Region
Canada and Western USA
Bars are relative to the 100 km total.
๐ Scientific Note: Volcanic risk assessments use peer-reviewed seismic-volcanic correlation models (Nishimura 2017, Jenkins 2024). These represent statistical probabilities, not predictions. Always follow official PHIVOLCS advisories.
How this is calculated โFAQ
Okmok erupts infrequently, so the chance in any single year is low. Based on Okmok's eruption history, our model estimates roughly a 6.7% chance of an eruption within the next 12 months (about one eruption every 14 years on average). This is a statistical estimate, not a definite prediction โ always follow official volcano observatory advisories.
Okmok's most recent known eruption was 2008 (per the Smithsonian Global Volcanism Program record).
Okmok is classified as active. It is a caldera in Aleutians, USA, rising to 1,073 m.
About 500 people live within 30 km of Okmok and roughly 5,000 within 100 km. The current modeled hazard level is moderate. Local hazard zones and typical eruption size are detailed on this page.
Okmok is located in Aleutians, USA, at 53.428ยฐ, -168.131ยฐ, with a summit elevation of 1,073 m.