Complex volcano โข Honshu, Japan
Possible, not imminent
An eruption at Asama in any given year is a real but minority possibility. Our model estimates a 39.3% chance of an eruption in the next 12 months โ about one eruption every ~2 years on average. Its most recent known eruption was 2019.
Statistical estimate, not a prediction โ medium confidence. Always follow official volcano observatory advisories. How this is calculated โ
39.3%
1-year
4%
30-day
~2y
recurrence
36.406ยฐ, 138.523ยฐ ยท Japan ยท 12 nearby earthquakes
39.3%
1-year probability
4%
30-day
~2y
Avg. recurrence
very high
Risk level
~1 eruption every 2 yr โ the GVP eruption frequency blended toward a complex volcano prior by how complete the record is.
145 dated eruptions over ~9219 yr โ a well-documented record the rate can rely on.
Most eruptions ~VEI 2; capable of large (VEI โฅ 4) events โ largest recorded VEI 5. ~2% 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 30โ50.3% (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.
explosive ยท high explosivity
Largest recorded: VEI 5
Most eruptions ~VEI 2; capable of large (VEI โฅ 4) events โ largest recorded VEI 5.
145 dated eruptions over ~9219 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
2,568m
Elevation
2019
Last Eruption
VEI 2
Explosivity Index
Complex volcano
Type
9 km ENE of Komoro, Japan
169.3km deep โข 8km away
2 km SSE of Iiyama, Japan
1.6km deep โข 48km away
17 km E of Iiyama, Japan
10.0km deep โข 51km away
7 km NE of Hotaka, Japan
2.9km deep โข 53km away
12 km ENE of Shibukawa, Japan
11.2km deep โข 56km away
6 km ESE of Maebashi, Japan
148.5km deep โข 56km away
1 km ENE of ลmachi, Japan
10.0km deep โข 58km away
23 km ENE of Iiyama, Japan
10.0km deep โข 59km away
7 km SSE of Hakuba, Japan
9.9km deep โข 61km away
15 km WSW of Chichibu, Japan
135.0km deep โข 61km away
10 km SSW of Hakuba, Japan
10.0km deep โข 65km away
12 km NNW of ลmachi, Japan
10.0km deep โข 68km away
Coordinates
36.4064ยฐN, 138.5230ยฐE
Region
Japan, Taiwan, Marianas
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
An eruption at Asama in any given year is a real but minority possibility. Based on Asama's eruption history, our model estimates roughly a 39.3% chance of an eruption within the next 12 months (about one eruption every 2 years on average). This is a statistical estimate, not a definite prediction โ always follow official volcano observatory advisories.
Asama's most recent known eruption was 2019 (per the Smithsonian Global Volcanism Program record).
Asama is classified as active. It is a complex volcano in Honshu, Japan, rising to 2,568 m.
About 350,000 people live within 30 km of Asama and roughly 8,000,000 within 100 km. The current modeled hazard level is very high. Local hazard zones and typical eruption size are detailed on this page.
Asama is located in Honshu, Japan, at 36.406ยฐ, 138.523ยฐ, with a summit elevation of 2,568 m.