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Furnas

Photo of this volcano
  • Portugal
  • Azores Triple Junction Volcanic Province
  • Composite | Stratovolcano
  • 1630 CE
  • Country
  • Volcanic Province
  • Landform | Volc Type
  • Last Known Eruption
  • 37.77°N
  • 25.32°W

  • 805 m
    2641 ft

  • 382100
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports available for Furnas.

The Global Volcanism Program has no Weekly Reports available for Furnas.

The Global Volcanism Program has no Bulletin Reports available for Furnas.

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 9 confirmed Holocene eruptive periods.

1630 Sep 3 - 1630 Nov 2 Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode South end of caldera (Pico da Areia)
1630 Sep 3 - 1630 Nov 2 Evidence from Observations: Reported

List of 14 Events for Episode 1 at South end of caldera (Pico da Areia)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava dome
   - - - -    - - - - Avalanche
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Pumice
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1630 Sep    - - - - Fatalities
1630 Sep 3    - - - - VEI (Explosivity Index)
1630 Sep 30    - - - - Fatalities

1441 ± 2 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode Center of caldera (Gaspar), Tephra layer I
1441 ± 2 years - Unknown Evidence from Observations: Reported

List of 6 Events for Episode 1 at Center of caldera (Gaspar), Tephra layer I

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava dome
   - - - -    - - - - Lapilli
   - - - -    - - - - Pumice
1441 ± 2 years    - - - - VEI (Explosivity Index)

1430 ± 100 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode East caldera floor, Tephra layer H
1430 ± 100 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 5 Events for Episode 1 at East caldera floor, Tephra layer H

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Pumice
1430 ± 100 years    - - - - VEI (Explosivity Index)

1170 ± 100 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode E caldera floor (Lake crater), Tephra layer G
1170 ± 100 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 4 Events for Episode 1 at E caldera floor (Lake crater), Tephra layer G

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
1170 ± 100 years    - - - - VEI (Explosivity Index)

0840 ± 100 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode Center of caldera (Gaspar), Tephra layer F
0840 ± 100 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 4 Events for Episode 1 at Center of caldera (Gaspar), Tephra layer F

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Lava dome
0840 ± 100 years    - - - - VEI (Explosivity Index)

0080 ± 100 years Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode N floor of younger caldera, Tephra layer C
0080 ± 100 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 6 Events for Episode 1 at N floor of younger caldera, Tephra layer C

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow weak or small
   - - - -    - - - - Ash
   - - - -    - - - - Pumice
   - - - -    - - - - Lahar or Mudflow
0080 ± 100 years    - - - - VEI (Explosivity Index)

0360 BCE ± 150 years Confirmed Eruption  

Episode 1 | Eruption Episode Tephra layer B
0360 BCE ± 150 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 3 Events for Episode 1 at Tephra layer B

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli

1670 BCE ± 1460 years Confirmed Eruption  

Episode 1 | Eruption Episode Tephra layer A
1670 BCE ± 1460 years - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at Tephra layer A

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli

4570 BCE (in or before) Confirmed Eruption  

Episode 1 | Eruption Episode East rim of caldera (Pico do Canário)
4570 BCE (in or before) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 2 Events for Episode 1 at East rim of caldera (Pico do Canário)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
Deformation History

There is no Deformation History data available for Furnas.

Emission History

There is no Emissions History data available for Furnas.

Photo Gallery

The village of Furnas (right) lies in the center of Furnas caldera, whose northern rim forms the ridge in the background. The largest eruption in the last 5,000 years originated at a vent where the village is now located. This Plinian eruption, named Furnas C, occurred about 1,900 years ago. Activity varied between phreatomagmatic and magmatic styles, producing massive fallout of pumice and ash and pyroclastic flows and surges.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
The low hill covered by fields (left center) is Pico do Gaspar lava dome, surrounded by a low tuff cone. The Lagoa das Furnas lies to the west (right) and the eastern caldera wall can be seen in the left background. The Pico do Gaspar dome has been the site of two eruptions, including in about 1439-1443 CE; descriptions suggest an initial explosive phase producing ash, followed by lava dome formation.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
Hydrothermal features at Furnas include several fields of fumaroles, hot springs, bubbling pools and mudpits, and the emission of carbon dioxide both at springs and through the soil. Fumarole fields are found on the north shore of Furnas Lake, in the river gorge of the Ribeira Quente, the Ribeira Quente village on the coast outside of the caldera, and in the upper Ribeira dos Tambores. A significant fumarole field, including the hot spring seen here, is located in the main fumarole field, Caldeiras das Furnas, in the village of Furnas.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
Furnas volcano, at the eastern end of Sao Miguel Island, contains two nested calderas. The southern rim of the younger 6-km-wide caldera is seen here from the north, with Furnas Lake on the right foreground. At least 10 trachytic pumice layers, all erupted during the past 5,000 years, post-date the caldera. The dome with the semi-circle of trees in the center behind the lake is the site of the most recent eruption at Furnas, a sub-Plinian eruption in 1630 CE.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
GVP Map Holdings

The Global Volcanism Program has no maps available for Furnas.

Smithsonian Sample Collections Database

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

External Sites