Logo link to homepage

São Jorge

Photo of this volcano
  • Portugal
  • Azores Triple Junction Volcanic Province
  • Cluster | Fissure vent
  • 1902 CE
  • Country
  • Volcanic Province
  • Landform | Volc Type
  • Last Known Eruption
  • 38.65°N
  • 28.08°W

  • 1053 m
    3455 ft

  • 382030
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 13 July-19 July 2022 Citation IconCite this Report

A seismic swarm at São Jorge began at 1605 on 19 March along a WNW-ESE fissure system stretching from Ponta dos Rosais to Norte Pequeno - Silveira. The seismic data as well as deformation data indicated a magmatic intrusion, though by early April no significant deformation was detected. The frequency of earthquakes had decreased in late May-early June, leading CIVISA to lower the Alert Level to V3 (on a scale of V0-V6) on 8 June. Seismicity continued to be elevated; by 18 July a total of 43,410 low-magnitude tectonic events had been recorded.

Source: Centro de Informação e Vigilância Sismovulcânica dos Açores (CIVISA)

Weekly Reports - Index


2022: March | July


13 July-19 July 2022 Citation IconCite this Report

A seismic swarm at São Jorge began at 1605 on 19 March along a WNW-ESE fissure system stretching from Ponta dos Rosais to Norte Pequeno - Silveira. The seismic data as well as deformation data indicated a magmatic intrusion, though by early April no significant deformation was detected. The frequency of earthquakes had decreased in late May-early June, leading CIVISA to lower the Alert Level to V3 (on a scale of V0-V6) on 8 June. Seismicity continued to be elevated; by 18 July a total of 43,410 low-magnitude tectonic events had been recorded.

Source: Centro de Informação e Vigilância Sismovulcânica dos Açores (CIVISA)


30 March-5 April 2022 Citation IconCite this Report

A seismic swarm beneath the W half of São Jorge began at 1605 on 19 March, with earthquakes along the Manadas volcanic fissure system between Velas (S side of the island) and Fajã do Ouvidor (N coast). On 31 March there were 714 seismic events detected, according to a preliminary analysis of seismic records. As the week progressed, the number of daily events fluctuated from 397 on 1 April to 592 on 5 April; magnitudes were relatively low. The Alert Level remained at V4 (on a scale of V0-V6).

Source: Centro de Informação e Vigilância Sismovulcânica dos Açores (CIVISA)


23 March-29 March 2022 Citation IconCite this Report

A seismic swarm beneath the W half of São Jorge began at 1605 on 19 March, with earthquakes along the Manadas volcanic fissure system between Velas (S side of the island) and Fajã do Ouvidor (N coast). CIVISA raised the Alert Level to V2 and then V3 (on a scale of V0-V6) during the morning of 20 March, and finally to V4 that afternoon. On 22 March Proteção Civil e Bombeiros dos Açores noted that, although no official evacuations had been issued, vulnerable people such as patients in the Velas health center were being moved to other locations on the island. Supplies were being distributed to São Jorge Island and residents were encouraged to prepare in case of a volcanic eruption. On 23 March a VONA was issued, announcing that the Aviation Color Code was raised to Yellow (on a four-color scale). The total estimated population of the island was around 8,400 people; according to a news report, about 1,250 residents left the island during 23-24 March. Most of the earthquakes were low magnitude, M 1.6-3.3, though about 209 of them were felt by residents; the largest event, a M 3.8, was detected near Velas at 2256 on 29 March. By 30 March a total of about 20,000 events had been recorded. Besides the increased seismicity, CIVISA noted that ground-based Global Navigation Satellite System (GNSS) data showed inflation, which was also suggested by satellite-based data processed by partners.

Sources: Portuguese American Journal; Centro de Informação e Vigilância Sismovulcânica dos Açores (CIVISA); Proteção Civil e Bombeiros dos Açores; U.S. News; Reuters; Açoriano Oriental; Açoriano Oriental


The Global Volcanism Program has no Bulletin Reports available for São Jorge.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 10 confirmed Holocene eruptive periods.

[ 1964 Feb 18 - 1964 Feb 18 ] Uncertain Eruption

Episode 1 | Uncertain Episode Submarine off SW coast
1964 Feb 18 - 1964 Feb 18 Evidence from Unknown
 Suspected submarine activity connected with seismic swarm.

List of 2 Events for Episode 1 at Submarine off SW coast

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Earthquakes (undefined)
1964 Feb 18    - - - - VEI (Explosivity Index)

[ 1907 ] Discredited Eruption

Submarine eruption (no details) listed in Mitchell-Thome (1981). This event has not been included in later eruptions lists by Azores volcanologists (through 2021), and may have been mistaken for the 1907 submarine eruption near Monaco Bank, S of Sao Miguel Island.

1902 May 7 - 1902 May 8 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Submarine, ~27 km ESE of Ponta do Topo
1902 May 7 - 1902 May 8 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Submarine, ~27 km ESE of Ponta do Topo

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Property Damage
1902 May 7    - - - - VEI (Explosivity Index)

1808 May 1 - 1808 Jun 10 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Sao Jorge
1808 May 1 - 1808 Jun 10 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Sao Jorge

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava flow
   - - - -    - - - - Fumarolic or Solfataric
   - - - -    - - - - Property Damage
1808    - - - - Fatalities
1808 May 1    - - - - VEI (Explosivity Index)

1800 Jun 24 - 1800 Jun 25 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Submarine, ~35 km SE of Ponta do Topo
1800 Jun 24 - 1800 Jun 25 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Submarine, ~35 km SE of Ponta do Topo

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1800 Jun 24    - - - - VEI (Explosivity Index)

[ 1757 Jul 9 - 1757 Jul 10 ] Discredited Eruption

Reported eruption coincided with a M 7.4 earthquake; supposedly 18 ephemeral islets formed during this activity. This event is not generally included in eruption lists by Azores volcanologists (through 2021), so was probably simply effects of the earthquake.

1580 May 1 - 1580 Aug 30 (?) Confirmed Eruption Max VEI: 3 (?)

Episode 1 | Eruption Episode Sao Jorge (SW side)
1580 May 1 - 1580 Aug 30 (?) Evidence from Observations: Reported

List of 7 Events for Episode 1 at Sao Jorge (SW side)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava flow
   - - - -    - - - - Property Damage
1580    - - - - Fatalities
1580    - - - - Fatalities
1580 May 1    - - - - VEI (Explosivity Index)

1483 Confirmed Eruption  

Episode 1 | Eruption Episode Sao Jorge
1483 - Unknown Evidence from Isotopic: 14C (calibrated)

1426 Confirmed Eruption  

Episode 1 | Eruption Episode Sao Jorge
1426 - Unknown Evidence from Isotopic: 14C (calibrated)

1293 Confirmed Eruption  

Episode 1 | Eruption Episode Sao Jorge
1293 - Unknown Evidence from Isotopic: 14C (calibrated)

1282 Confirmed Eruption  

Episode 1 | Eruption Episode Sao Jorge
1282 - Unknown Evidence from Isotopic: 14C (calibrated)

0412 Confirmed Eruption  

Episode 1 | Eruption Episode Sao Jorge
0412 - Unknown Evidence from Isotopic: 14C (calibrated)

2137 BCE Confirmed Eruption  

Episode 1 | Eruption Episode Sao Jorge
2137 BCE - Unknown Evidence from Isotopic: 14C (calibrated)
Deformation History

There is no Deformation History data available for São Jorge.

Emission History

There is no Emissions History data available for São Jorge.

GVP Map Holdings

The Global Volcanism Program has no maps available for São Jorge.

Smithsonian Sample Collections Database

There are no samples for São Jorge in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites