Caldera โข Kyushu, Japan
Possible, not imminent
An eruption at Aso 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 2021.
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
32.884ยฐ, 131.104ยฐ 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 caldera prior by how complete the record is.
187 dated eruptions over ~10071 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 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 moderate explosivity
Largest recorded: VEI 3
Most eruptions ~VEI 2; no large (VEI โฅ 4) eruption in the documented record.
187 dated eruptions over ~10071 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
1,592m
Elevation
2021
Last Eruption
VEI 2
Explosivity Index
Caldera
Type
4 km NE of Aso, Japan
15.4km deep โข 9km away
10 km N of Aso, Japan
10.0km deep โข 17km away
15 km SSW of Tsukawaki, Japan
9.8km deep โข 28km away
8 km NNE of Takedamachi, Japan
104.7km deep โข 36km away
12 km NNE of Takedamachi, Japan
102.7km deep โข 38km away
7 km NNW of Uto, Japan
10.0km deep โข 45km away
1 km WNW of Uto, Japan
10.0km deep โข 47km away
7 km NW of Uto, Japan
10.0km deep โข 50km away
36 km NE of Hitoyoshi, Japan
126.3km deep โข 53km away
6 km WSW of Matsubase, Japan
10.0km deep โข 55km away
7 km WSW of Uki, Japan
11.3km deep โข 58km away
3.5 km NE of Honmachi, Japan
10.0km deep โข 60km away
Coordinates
32.8842ยฐN, 131.1040ยฐE
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 Aso in any given year is a real but minority possibility. Based on Aso'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.
Aso's most recent known eruption was 2021 (per the Smithsonian Global Volcanism Program record).
Aso is classified as active. It is a caldera in Kyushu, Japan, rising to 1,592 m.
About 380,000 people live within 30 km of Aso and roughly 2,500,000 within 100 km. The current modeled hazard level is very high. Local hazard zones and typical eruption size are detailed on this page.
Aso is located in Kyushu, Japan, at 32.884ยฐ, 131.104ยฐ, with a summit elevation of 1,592 m.