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Photo of this volcano
  • Portugal
  • Atlantic Ocean
  • Stratovolcano
  • 1630 CE
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 37.77°N
  • 25.32°W

  • 805 m
    2641 ft

  • 382100
  • Latitude
  • Longitude

  • Summit

  • Volcano

The Global Volcanism Program has no activity reports 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 Holocene eruptive periods.

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1630 Sep 3 1630 Nov 2 Confirmed 5 Historical Observations South end of caldera (Pico da Areia)
1441 ± 2 years Unknown Confirmed 4 Historical Observations Center of caldera (Gaspar), Tephra layer I
1430 ± 100 years Unknown Confirmed 3 Radiocarbon (uncorrected) East caldera floor, Tephra layer H
1170 ± 100 years Unknown Confirmed 4 Radiocarbon (uncorrected) E caldera floor (Lake crater), Tephra layer G
0840 ± 100 years Unknown Confirmed 4 Radiocarbon (uncorrected) Center of caldera (Gaspar), Tephra layer F
0080 ± 100 years Unknown Confirmed 5 Radiocarbon (uncorrected) N floor of younger caldera, Tephra layer C
0360 BCE ± 150 years Unknown Confirmed   Radiocarbon (uncorrected) Tephra layer B
1670 BCE ± 1460 years Unknown Confirmed   Tephrochronology Tephra layer A
4570 BCE (in or before) Unknown Confirmed   Radiocarbon (uncorrected) East rim of caldera (Pico do Canário)
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 post-caldera Furnas tephra, layer C, originated from a vent where part of the village of Furnas is now located. The eruption was dated at about 2900 years before present. Plinian and sub-plinian eruptions deposited airfall-pumice and -ash, accompanied by local pyroclastic flows and late-stage mudflows.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
The low hill covered by fields (left-center) is Pico do Gaspar lava dome, which lies east of Lagoa das Furnas. Plinian eruptions about 1100 years ago including local pyroclastic flows accompanied formation of two nested pumice rings. An arcuate line of trees about halfway between the lake and the summit of the lava dome marks the rim of the northern pumice ring. The eruption concluded with emplacement of the Pico do Gaspar trachytic lava dome.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
Abundant thermal features exist at Furnas volcano. Some hot springs occur near the caldera lake. This hot spring in the town of Furnas is part of the main fumarole field, which is located in the eastern part of the caldera. The fumarole field contains boiling hot springs and mudpots and is associated with caldera-bounding faults and late-Holocene eruptive vents. A few other fumaroles are located along a gorge of the small river that drains the caldera and on the southern flank, near the coast.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
Furnas volcano, at the eastern end of Sao Miguel Island, contains at least two calderas. The younger 6-km-wide caldera is seen here from its northern rim. At least 11 trachytic pumice layers, all erupted during the past 5000 years, post-date the caldera. A zone of late-Pleistocene to Holocene basaltic-to-trachytic cinder cones and lava domes is located between Furnas and neighboring Agua de Pau volcano. The only historical eruption of Furnas volcano, during 1630, was one of the largest Holocene eruptions in the Azores.

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