Data from the Global Volcanism Program of the Smithsonian Institution
Details for: Furnas
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).
Volcano Number:382100
Volcano Name:Furnas
Country:Portugal
Volcano Type:Stratovolcano
Last Eruption:1630 CE
Elevation:805m
Tectonic Setting:Rift zone / Oceanic crust (< 15 km)
Pop. within 5km:1333
Pop. within 10km:7310
Pop. within 30km:87865
Pop. within 100km:153182
Latitude:37.77
Longitude:-25.32



Eruption Data from the Global Volcanism Program of the Smithsonian Institution
Volcano Number Volcano Name Eruption Number Activity Type Explosivity Index Max Explosivity Index Modifier Activity Area Activity Unit Start Evidence Method Start Date End Date
382100 Furnas 13034 Confirmed Eruption East rim of caldera (Pico do Canário) Radiocarbon (uncorrected) -4570
382100 Furnas 13035 Confirmed Eruption Tephra layer A Tephrochronology -1670
382100 Furnas 13036 Confirmed Eruption Tephra layer B Radiocarbon (uncorrected) -360
382100 Furnas 13037 Confirmed Eruption 5 N floor of younger caldera Tephra layer C Radiocarbon (uncorrected) 80
382100 Furnas 13038 Confirmed Eruption 4 Center of caldera (Gaspar) Tephra layer F Radiocarbon (uncorrected) 840
382100 Furnas 13039 Confirmed Eruption 4 E caldera floor (Lake crater) Tephra layer G Radiocarbon (uncorrected) 1170
382100 Furnas 13040 Confirmed Eruption 3 East caldera floor Tephra layer H Radiocarbon (uncorrected) 1430
382100 Furnas 13041 Confirmed Eruption 4 Center of caldera (Gaspar) Tephra layer I Historical Observations 1441
382100 Furnas 13042 Confirmed Eruption 5 South end of caldera (Pico da Areia) Historical Observations 1630/9/3 1630/11/2
Emissions Data from the Global Volcanism Program of the Smithsonian Institution
Sorry. No emissions data found for this volcano.


Data from the Earthchem Library
Sorry. No data exist for this volcano in the EarthChem Library.
Data from the Earthchem Portal


Data from the SESAR Database


Data from the MaGa Database
Location: Furnas Ribeira Quente area (View Details at MaGa DB)
Description: Diffuse degassing in Ribeira Quente area.
Hazard Description: n.a.
Type: soil_diffuse_emission
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas
Gas Flux Data:
Measurement Name Detail Date Specie Flux Std. Dev. Unit of Measure
Furnas Ribeira Quente area_062007 Detail 2007/06/01 CO2 243 43 Mg/d

Location: Furnas caldera (View Details at MaGa DB)
Description: Degassing at Furnas caldera (São Miguel Island, Azores) is mostly associated with the main fumarolic fields, and CO2 soil degassing is the surface expression of rising steam from the hydrothermal system.
Hazard Description: At Furnas village, inside Furnas volcano caldera, about 62% of the 896 houses are within the CO2 anomaly, 5% being in areas of moderate to high risk. Several inhabitants witnessed symptoms associated with high CO2 concentrations during certain periods, as well as the death of small animals (e.g., birds, chicken, and cats) in some depressed areas.
Type: soil_diffuse_emission
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas
Gas Flux Data:
Measurement Name Detail Date Specie Flux Std. Dev. Unit of Measure
Furnas caldera_062007 Detail 2007/06/01 CO2 959 84 Mg/d

Location: Furnas do Enxofre fumarolic field (View Details at MaGa DB)
Description: Permanent fumarolic activity inside a huge cave located in the only caldera of the island, whose origin is related to the collapse phase and drainage of a lava lake in the interior of the caldera.
Hazard Description: n.a.
Type: soil_diffuse_emission
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas

Location: Furnas Village (View Details at MaGa DB)
Description: Area interested by soil diffuse degassing, fumaroles, cold and thermal springs.
Hazard Description: One third of Furnas village houses are located over important diffuse degassing tectonic structures.
Type: soil_diffuse_emission
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas
Gas Flux Data:
Measurement Name Detail Date Specie Flux Std. Dev. Unit of Measure
Furnas Village_062007 Detail 2007/06/01 CO2 17 2 Mg/d
Furnas village CdA_22082014 Detail 2014/08/22 CO2 3.2 0.2 Mg/d

Location: Furnas lake (View Details at MaGa DB)
Description: Discrete soil diffuse degassing and fumarolic manifestations in the area close to the Furnas lake.
Hazard Description: n.a.
Type: soil_diffuse_emission
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas
Gas Flux Data:
Measurement Name Detail Date Specie Flux Std. Dev. Unit of Measure
Furnas lake_01062007 Detail 2007/06/01 CO2 14 2 Mg/d
Furnas lake WJ_19082014 Detail 2014/08/19 CO2 6 0.2 Mg/d

Location: Furnas lake fumaroles (View Details at MaGa DB)
Description: Hydrothermal activity is widespread on the island and includes soil diffuse degassing areas steaming ground, thermal springs, cold CO2-rich springs, and lowtemperature fumaroles (95–100 °C), mostly concentrated inside the Furnas caldera (where three main fumarolic fields are observed).
Hazard Description: not reporetd
Type: fumarole
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas
Gas Flux Data:
Measurement Name Detail Date Specie Flux Std. Dev. Unit of Measure
Furnas lake ST_19082014 Detail 2014/08/19 CO2 11.4 4.7 Mg/d
Furnas lake WJ_19082014 Detail 2014/08/19 CO2 17.6 5.3 Mg/d
Furnas lake WJ_19082014 Detail 2014/08/19 H2S 0.08 0 Mg/d

Location: Furnas Village fumarole (View Details at MaGa DB)
Description: Furnas Village is the largest fumarolic field in the Furnas caldera. Several moderate to large fumaroles are active within an area of several hundred square meters. “Caldeira Grande” and “Caldeira do Asmodeu” are the main hydrothermal vent manifestations (CG and CdA).
Hazard Description: not reported
Type: fumarole
Region: Azores, Portugal
Country: Portugal
Volcanic Complex: Furnas
Gas Flux Data:
Measurement Name Detail Date Specie Flux Std. Dev. Unit of Measure
Furnas village CdA_22082014 Detail 2014/08/22 CO2 17.8 4.1 Mg/d
Furnas village CG_22082014 Detail 2014/08/22 CO2 3 0.8 Mg/d