Complex volcano โข Kyushu, Japan
Unlikely in any given year
Unzen erupts infrequently, so the chance in any single year is low. Our model estimates a 4.6% chance of an eruption in the next 12 months โ about one eruption every ~21 years on average. Its most recent known eruption was 1995.
Statistical estimate, not a prediction โ medium confidence. Always follow official volcano observatory advisories. How this is calculated โ
4.6%
1-year
0.4%
30-day
~21y
recurrence
32.757ยฐ, 130.294ยฐ ยท Japan ยท 12 nearby earthquakes
4.6%
1-year probability
0.4%
30-day
~21y
Avg. recurrence
low
Risk level
~1 eruption every 21 yr โ the GVP eruption frequency blended toward a complex volcano prior by how complete the record is.
14 dated eruptions over ~6046 yr โ a well-documented record the rate can rely on.
Most eruptions ~VEI 2; no large (VEI โฅ 4) eruption in the documented record.
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 3.3โ6.4% (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 low explosivity
Largest recorded: VEI 2
Most eruptions ~VEI 2; no large (VEI โฅ 4) eruption in the documented record.
14 dated eruptions over ~6046 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
1,500m
Elevation
1995
Last Eruption
VEI 3
Explosivity Index
Complex volcano
Type
19 km NNW of Hondomachi-hondo, Japan
10.0km deep โข 23km away
10 km E of Nagasaki, Japan
10.0km deep โข 28km away
7 km NW of Uto, Japan
10.0km deep โข 29km away
7 km ESE of Nagasaki, Japan
10.0km deep โข 32km away
8 km NNW of Honmachi, Japan
15.5km deep โข 32km away
7 km NNW of Uto, Japan
10.0km deep โข 33km away
6 km WSW of Matsubase, Japan
10.0km deep โข 33km away
12 km S of Kashima, Japan
11.9km deep โข 34km away
7 km WSW of Uki, Japan
11.3km deep โข 34km away
1 km WNW of Uto, Japan
10.0km deep โข 35km away
2 km NE of ?muta, Japan
10.0km deep โข 37km away
3.5 km NE of Honmachi, Japan
10.0km deep โข 40km away
Coordinates
32.7569ยฐN, 130.2944ยฐE
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
Unzen erupts infrequently, so the chance in any single year is low. Based on Unzen's eruption history, our model estimates roughly a 4.6% chance of an eruption within the next 12 months (about one eruption every 21 years on average). This is a statistical estimate, not a definite prediction โ always follow official volcano observatory advisories.
Unzen's most recent known eruption was 1995 (per the Smithsonian Global Volcanism Program record).
Unzen is classified as active. It is a complex volcano in Kyushu, Japan, rising to 1,500 m.
About 450,000 people live within 30 km of Unzen and roughly 2,000,000 within 100 km. The current modeled hazard level is low. Local hazard zones and typical eruption size are detailed on this page.
Unzen is located in Kyushu, Japan, at 32.757ยฐ, 130.294ยฐ, with a summit elevation of 1,500 m.