What was erupting in the year...?
There were 67 confirmed eruptions at some point during 1991 from 65 different volcanoes; 37 of those were new eruptions that started during the year. A stop date with "(continuing)" indicates that the eruption was considered to be ongoing as of the date indicated. Data is reported through the last data update (19 September 2025). Information about more recent eruptions can be found in the Smithsonian / USGS Weekly Volcanic Activity Report.
| Volcano | Country | Eruption Start Date | Eruption Stop Date | Eruption Type | Max VEI |
|---|---|---|---|---|---|
| Kirishimayama | Japan | 1991 Dec 1 | 1992 Apr 19 | Explosive / Effusive | 1 |
| Northern EPR at 9.8°N | Undersea Features | 1991 Dec 1 ± 29 days | 1992 Feb 5 ± 29 days | Submarine | 0 |
| Westdahl | United States | 1991 Nov 29 | 1992 Jan 14 | Explosive / Effusive | 3 |
| Iliboleng | Indonesia | 1991 Nov 3 | 1991 Nov 15 | Explosive / Effusive | 1 |
| Lascar | Chile | 1991 Oct 21 | 1992 May 23 (?) | Explosive / Effusive | 2 |
| Marchena | Ecuador | 1991 Sep 25 | 1991 Nov 16 (?) ± 15 days | Explosive / Effusive | 2 |
| Nyamulagira | DR Congo | 1991 Sep 20 | 1993 Feb 8 | Explosive / Effusive | 3 |
| Akutan | United States | 1991 Sep 15 | 1991 Oct 29 ± 1 days | Explosive / Effusive | 2 |
| Raung | Indonesia | 1991 Sep 10 | 1991 Nov 12 (?) | Explosive / Effusive | 2 |
| Villarrica | Chile | 1991 Aug 30 | 1991 Sep 17 | Explosive / Effusive | 2 |
| Cerro Hudson | Chile | 1991 Aug 8 | 1991 Oct 27 | Explosive / Effusive | 5 |
| Piton de la Fournaise | France | 1991 Jul 19 | 1991 Jul 20 | Explosive / Effusive | 0 |
| Karthala | Union of the Comoros | 1991 Jul 11 | 1991 Jul 11 | Explosive / Effusive | 2 |
| Ruapehu | New Zealand | 1991 Jul 5 (?) | 1991 Jul 14 (?) | Explosive / Effusive | 1 |
| Karangetang | Indonesia | 1991 Jul 2 (on or before) | 1993 Dec 31 (on or after) | Explosive / Effusive | 2 |
| Peuet Sague | Indonesia | 1991 Jul 2 ± 182 days | Unknown | 2 | |
| Lateiki | Tonga | 1991 Jun 24 (on or before) | Unknown | 0 | |
| Soputan | Indonesia | 1991 May 22 | 1996 Sep 29 (on or after) | Explosive / Effusive | 2 |
| Lokon-Empung | Indonesia | 1991 May 17 | 1992 Jan 16 ± 15 days | Explosive / Effusive | 3 |
| Ontakesan | Japan | 1991 May 13 | 1991 May 16 | Explosive / Effusive | 0 |
| Lewotobi | Indonesia | 1991 May 11 | 1992 Dec 31 (on or after) | Explosive / Effusive | 1 |
| Iliboleng | Indonesia | 1991 May 8 | 1991 Jun 30 (on or after) | Explosive / Effusive | 1 |
| Rincon de la Vieja | Costa Rica | 1991 May 7 | 1992 Sep 16 ± 15 days | Explosive / Effusive | 2 |
| Kavachi | Solomon Islands | 1991 May 4 (on or before) | 1991 Sep 16 ± 15 days | Explosive / Effusive | 2 |
| Fernandina | Ecuador | 1991 Apr 19 | 1991 Apr 24 | Explosive / Effusive | 2 |
| Klyuchevskoy | Russia | 1991 Apr 8 | 1991 Jun 24 (?) | Explosive / Effusive | 2 |
| Pinatubo | Philippines | 1991 Apr 2 | 1991 Sep 2 | Explosive / Effusive | 6 |
| Barren Island | India | 1991 Apr 1 | 1991 Oct 31 ± 7 days | Explosive / Effusive | 2 |
| Ranakah | Indonesia | 1991 Mar 16 (on or before) ± 15 days | Unknown | 1 | |
| Poas | Costa Rica | 1991 Mar 6 | 1991 Sep 16 ± 15 days | Explosive / Effusive | 1 |
| Colima | Mexico | 1991 Mar 1 | 1991 Oct 16 ± 15 days | Explosive / Effusive | 2 |
| Kanlaon | Philippines | 1991 Feb 14 | 1991 Feb 14 | Explosive / Effusive | 2 |
| Planchon-Peteroa | Chile | 1991 Feb 9 | 1991 Mar 2 ± 2 days | Explosive / Effusive | 2 |
| Northern EPR at 9.8°N | Undersea Features | 1991 Jan 27 ± 29 days | 1991 Mar 26 ± 29 days | Submarine | 0 |
| Hekla | Iceland | 1991 Jan 17 | 1991 Mar 11 | Explosive / Effusive | 3 |
| Ebeko | Russia | 1991 Jan 16 ± 15 days | 1991 Jan 16 ± 15 days | Explosive / Effusive | 1 |
| Avachinsky | Russia | 1991 Jan 13 | 1991 Jan 30 | Explosive / Effusive | 2 |
| Unzendake | Japan | 1990 Nov 17 | 1995 Feb 16 ± 15 days | Explosive / Effusive | 1 |
| St. Helens | United States | 1990 Nov 5 | 1991 Feb 14 | Explosive / Effusive | 3 |
| Ambrym | Vanuatu | 1990 Sep 16 (on or before) ± 15 days | 1991 Jul 16 (on or after) ± 15 days | Explosive / Effusive | 2 |
| Monowai | New Zealand | 1990 May 30 | 1991 Mar 25 | Explosive / Effusive | 0 |
| Sabancaya | Peru | 1990 May 28 | 1998 Sep 16 (?) ± 15 days | Explosive / Effusive | 3 |
| Suwanosejima | Japan | 1990 Apr 16 ± 15 days | 1996 Jul 14 | Explosive / Effusive | 2 |
| Bezymianny | Russia | 1990 Jan 29 | 1991 Nov 29 | Explosive / Effusive | 3 |
| Sheveluch | Russia | 1990 Jan 10 | 1995 Feb 16 ± 15 days | Explosive / Effusive | 3 |
| Galeras | Colombia | 1990 Jan 7 | 1992 Jul 16 | Explosive / Effusive | 2 |
| Pacaya | Guatemala | 1990 Jan 4 (?) | 2000 Mar 1 | Explosive / Effusive | 3 |
| Asosan | Japan | 1989 Apr 5 | 1991 Feb 9 | Explosive / Effusive | 2 |
| Marapi | Indonesia | 1987 Jan 15 | 1994 Aug 12 (on or after) | Explosive / Effusive | 2 |
| Whakaari/White Island | New Zealand | 1986 Feb 1 (?) | 1994 Jul 28 | Explosive / Effusive | 3 |
| Nevado del Ruiz | Colombia | 1985 Sep 11 | 1991 Jul 13 | Explosive / Effusive | 3 |
| Kilauea | United States | 1983 Jan 3 | 2018 Sep 5 | Explosive / Effusive | 3 |
| Ol Doinyo Lengai | Tanzania | 1983 Jan 1 | 1993 Sep 24 | Explosive / Effusive | 2 |
| Etna | Italy | 1979 Jul 3 | 1993 Mar 30 | Explosive / Effusive | 2 |
| Manam | Papua New Guinea | 1974 Mar 4 (?) | 1999 Nov 9 (?) | Explosive / Effusive | 3 |
| Langila | Papua New Guinea | 1973 Feb 24 ± 4 days | 2000 Oct 16 (on or after) ± 15 days | Explosive / Effusive | 3 |
| Erebus | Antarctica | 1972 Dec 16 (on or before) ± 15 days | 2025 Sep 19 (continuing) | Lava Lake | 2 |
| Bagana | Papua New Guinea | 1972 Jul 2 ± 182 days | 1995 Jul 2 (on or after) ± 182 days | Explosive / Effusive | 2 |
| Arenal | Costa Rica | 1968 Jul 29 | 2010 Dec 16 (?) ± 15 days | Explosive / Effusive | 3 |
| Semeru | Indonesia | 1967 Aug 31 | 2009 Mar 15 | Explosive / Effusive | 3 |
| Erta Ale | Ethiopia | 1967 Jul 2 (in or before) ± 182 days | 2025 Sep 19 (continuing) | Explosive / Effusive | 0 |
| Aira | Japan | 1955 Oct 13 | 2016 Aug 22 | Explosive / Effusive | 3 |
| Sangay | Ecuador | 1934 Aug 8 | 2011 Mar 2 | Explosive / Effusive | 3 |
| Stromboli | Italy | 1934 Feb 2 | 2025 Sep 19 (continuing) | Explosive / Effusive | 2 |
| Dukono | Indonesia | 1933 Aug 13 | 2025 Sep 19 (continuing) | Explosive / Effusive | 3 |
| Santa Maria | Guatemala | 1922 Jun 22 | 2025 Sep 19 (continuing) | Explosive / Effusive | 3 |
| Yasur | Vanuatu | 1270 ± 110 years | 2025 Sep 19 (continuing) | Explosive / Effusive | 3 |
List of Questions
Global Volcanism Program, 2025. [Database] Volcanoes of the World (v. 5.3.3; 26 Nov 2025). Distributed by Smithsonian Institution, compiled by Venzke, E. https://doi.org/10.5479/si.GVP.VOTW5-2025.5.3
