Eruption history
VEI – Volcanic Explosivity Index: 0 = lava outpouring, 4 = like Eyjafjallajökull 2010, 6 = like Pinatubo 1991, 7 = like Tambora 1815. The scale is logarithmic – each step is about 10 times more material.
| Start | End | VEI | Vent and dating |
|---|---|---|---|
| 29 May 2008 | 17 June 2008 | 1 | Summit and SE flank · Observations: Reported |
| 15 September 1998 | 21 October 1998 | 1 | N & W caldera floor, SE flank (630-680 m) · Observations: Reported |
| 29 January 1979 | 4 March 1979 | 2 | East flank (300 m) and summit · Observations: Reported |
| 29 June 1959 | 31 July 1959 | 2 | East flank · Observations: Reported |
| 2 July 1951 | — | ? | Observations: Reported |
| c. 2 July 1949 | — | 0 | Observations: Reported |
| 30 June 1948 | — | 0 | Observations: Reported |
| 13 April 1943 | 11 May 1943 | 3 | Caldera ring fracture · Observations: Reported |
| 2 July 1940 | — | 0 | East flank (Cerro de Las Animas) · Observations: Reported |
| 2 July 1932 | — | 1 | Observations: Reported |
| c. 2 July 1850 | — | ? | Isotopic: Cosmic Ray Exposure |
| c. 1250 | — | 0 | Isotopic: Cosmic Ray Exposure |
| 550 BCE ± 1,300 years | — | 0 | Isotopic: Cosmic Ray Exposure |
| 950 BCE ± 900 years | — | 0 | Isotopic: Cosmic Ray Exposure |
Data: Global Volcanism Program, Smithsonian Institution (#353060)