Caldera • Vatnajökull, Iceland
Possible, not imminent
An eruption at Grímsvötn in any given year is a real but minority possibility. Our model estimates a 26% chance of an eruption in the next 12 months — about one eruption every ~3 years on average. Its most recent known eruption was 2011.
Statistical estimate, not a prediction — medium confidence. Always follow official volcano observatory advisories. How this is calculated →
26%
1-year
2.4%
30-day
~3y
recurrence
64.420°, -17.330° · Iceland · 12 nearby earthquakes
26%
1-year probability
2.4%
30-day
~3y
Avg. recurrence
high
Risk level
~1 eruption every 3 yr — the GVP eruption frequency blended toward a caldera prior by how complete the record is.
85 dated eruptions over ~10241 yr — a well-documented record the rate can rely on.
Most eruptions ~VEI 2; capable of large (VEI ≥ 4) events — largest recorded VEI 6. ~1.2% chance of a VEI ≥ 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 →Poisson estimate from the GVP eruption frequency, blended toward a volcano-type prior by how complete the record is and adjusted for recency — 1-year range 19.4–34.4% (confidence medium; no live seismic feed for this volcano). Philippine volcanoes additionally use live PHIVOLCS alert levels and seismicity — see the Risk Analysis dashboard.
explosive · very high explosivity
Largest recorded: VEI 6
Most eruptions ~VEI 2; capable of large (VEI ≥ 4) events — largest recorded VEI 6.
85 dated eruptions over ~10241 yr — a well-documented record the rate can rely on.
Size from the volcano's VEI record combined with the global eruption size–frequency relation; the record grade reflects how complete its eruptive history is — sparse records lean on a volcano-type prior with wider uncertainty. How this is calculated →
1,725m
Elevation
2011
Last Eruption
VEI 4
Explosivity Index
Caldera
Type
111 km W of Höfn, Iceland
10.0km deep • 8km away
104 km WNW of Höfn, Iceland
10.0km deep • 14km away
117 km WNW of Höfn, Iceland
7.1km deep • 15km away
118 km WNW of Höfn, Iceland
8.2km deep • 16km away
115 km WNW of Höfn, Iceland
10.0km deep • 16km away
119 km WNW of Höfn, Iceland
10.0km deep • 19km away
108 km WNW of Höfn, Iceland
10.0km deep • 19km away
118 km WNW of Höfn, Iceland
10.0km deep • 20km away
123 km WNW of Höfn, Iceland
7.6km deep • 20km away
110 km WNW of Höfn, Iceland
10.0km deep • 21km away
120 km WNW of Höfn, Iceland
10.0km deep • 22km away
122 km WNW of Höfn, Iceland
8.6km deep • 22km away
Coordinates
64.4200°N, -17.3300°E
Region
Iceland and Arctic Ocean
Bars are relative to the 100 km total.
📊 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 →FAQ
An eruption at Grímsvötn in any given year is a real but minority possibility. Based on Grímsvötn's eruption history, our model estimates roughly a 26% chance of an eruption within the next 12 months (about one eruption every 3 years on average). This is a statistical estimate, not a definite prediction — always follow official volcano observatory advisories.
Grímsvötn's most recent known eruption was 2011 (per the Smithsonian Global Volcanism Program record).
Grímsvötn is classified as active. It is a caldera in Vatnajökull, Iceland, rising to 1,725 m.
About 100 people live within 30 km of Grímsvötn and roughly 20,000 within 100 km. The current modeled hazard level is high. Local hazard zones and typical eruption size are detailed on this page.
Grímsvötn is located in Vatnajökull, Iceland, at 64.420°, -17.330°, with a summit elevation of 1,725 m.