Stratovolcano โข Eastern Visayas, Philippines
Island volcano with active geothermal system.
Unlikely in any given year
Biliran erupts infrequently, so the chance in any single year is low. Our model estimates a 3.8% chance of an eruption in the next 12 months โ about one eruption every ~50 years on average. Its most recent known eruption was 1939.
Statistical estimate, not a prediction โ low confidence. Always follow official PHIVOLCS advisories. How this is calculated โ
3.8%
1-year
0.3%
30-day
~50y
recurrence
11.523ยฐ, 124.535ยฐ ยท Philippines ยท 12 nearby earthquakes
Biliran, Eastern Visayas ยท Stratovolcano
low confidenceยท 2 stationsยท no hazard map
๐ No specific action required.
Near the long-run baseline โ only background factors are mildly elevated.
How this number is built
What's driving it
Activity level 2/3
b=0.68 (low) ยท Mc 2.2 ยท n=665
Minimal indicators detected.
Near the long-run baseline โ only background factors are mildly elevated.
Activity level 2/3
A vigorous open hydrothermal system raises the chance of steam-driven (phreatic) activity.
Basis: PHIVOLCS hydrothermal monitoring
b = 0.68 (low) ยท Mc 2.2 ยท n=665
Low b-value (0.68) suggests high stress accumulation and potential for larger events
Basis: GutenbergโRichter b-value (Aki 1965; Wiemer & Wyss 2000)
Status-based estimate (~1 per 50 yr)
Anchor โ the average eruption frequency this volcano has shown historically.
Basis: Smithsonian Global Volcanism Program eruption record
Alert Level 0
No significant unrest โ eruption not expected in the near term.
Basis: PHIVOLCS Volcano Alert Level System
Recurrence interval not well constrained
No data-derived recurrence interval โ repose effect not modeled.
Basis: Weibull/renewal repose model (Bebbington & Lai 1996; Marzocchi & Bebbington 2012)
No eruptions in the last 10 years.
Volcanic activity clusters in episodes โ recent eruptions raise near-term probability.
Basis: GVP eruption history
No qualifying large earthquakes in range/time window
Large nearby earthquakes can perturb the magma/hydrothermal system (static + dynamic stress).
Basis: Nishimura (2017) GRL 44; Jenkins et al. (2024) Volcanica
0 events within 15 km ยท 0.1/day
Elevated shallow, near-field seismicity can indicate magma or fluid movement.
Basis: Volcano-seismic monitoring (PHIVOLCS / USGS)
No coherent migration detected
Insufficient data for depth migration analysis
Basis: Hypocenter migration (Roman & Cashman 2006)
No acceleration detected
Accelerating seismicity can precede failure of the edifice/conduit.
Basis: Material-failure forecasting (Voight 1988; Kilburn 2003)
No significant clustering
Swarms and clusters indicate stress concentration or fluid migration beneath the edifice.
Basis: Seismic cluster analysis
No data-derived recurrence interval โ repose effect not modeled.
Detailed instrument readouts
Normal โ no significant unrest
0.68 ยฑ 0.03
Mc 2.2 ยท n=665
Low b-value (0.68) suggests high stress accumulation and potential for larger events
No coherent migration detected
Insufficient data for depth migration analysis
No acceleration detected
859
analyzed
213
M3+
25
M4+
7
M5+
0
<5km deep
0
<15km away
0.1
ev/day
Smithsonian GVP eruption frequency โ about one eruption every ~50 years.
Normal โ no significant unrest reported.
Product of b-value, depth migration, acceleration, triggering & swarm signals.
Confidence: Limited monitoring or sparse local seismicity โ the estimate leans on the long-run base rate.
How this is calculated โModeled from PHIVOLCS alert level + live seismicity + eruption history. See the Risk Analysis dashboard for all volcanoes side by side.
gentle ยท low explosivity
Largest recorded: VEI 1
Most eruptions ~VEI 1; no large (VEI โฅ 4) eruption in the documented record.
Sparse / largely unknown history (1 recorded) โ the rate is dominated by a volcano-type prior, with wide uncertainty.
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
1,301m
Elevation
1939
Last Eruption
Stratovolcano
Type
โ
Recorded Eruptions
~50y
Avg. Recurrence
1939
Last Eruption
Baseline eruption rate derived from Smithsonian GVP confirmed-eruption frequency. Current eruption probability (incorporating PHIVOLCS alert level and live seismicity) is on the Risk Analysis dashboard.
002 km S 56ยฐ E of Biliran (Biliran)
5.0km deep โข 9km away
001 km S 33ยฐ W of Biliran (Biliran)
3.0km deep โข 10km away
003 km S 21ยฐ E of Biliran (Biliran)
2.0km deep โข 10km away
006 km N 74ยฐ W of Culaba (Biliran)
23.0km deep โข 17km away
002 km N 87ยฐ W of Naval (Biliran)
3.0km deep โข 18km away
009 km N 59ยฐ W of Capoocan (Leyte)
2.0km deep โข 22km away
010 km S 40ยฐ E of Leyte (Leyte)
5.0km deep โข 25km away
LEYTE, PHILIPPINES
5.0km deep โข 25km away
LEYTE, PHILIPPINES
6.0km deep โข 25km away
008 km N 82ยฐ W of Capoocan (Leyte)
6.0km deep โข 25km away
008 km N 86ยฐ W of Capoocan (Leyte)
5.0km deep โข 25km away
009 km S 86ยฐ W of Capoocan (Leyte)
7.0km deep โข 26km away
Coordinates
11.5230ยฐN, 124.5350ยฐE
Region
Philippines and SE Asia
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
Biliran erupts infrequently, so the chance in any single year is low. Based on Biliran's eruption history, our model estimates roughly a 3.8% chance of an eruption within the next 12 months (about one eruption every 50 years on average). This is a statistical estimate, not a definite prediction โ always follow official PHIVOLCS advisories.
Biliran's most recent known eruption was 1939 (per the Smithsonian Global Volcanism Program record).
Biliran is classified as active. It is a stratovolcano in Eastern Visayas, Philippines, rising to 1,301 m.
About 65,000 people live within 30 km of Biliran. The current modeled hazard level is low. Local hazard zones and typical eruption size are detailed on this page.
Biliran is located in Eastern Visayas, Philippines, at 11.523ยฐ, 124.535ยฐ, with a summit elevation of 1,301 m.